Class: String
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Subclasses:
|
|
Super Chains via Extension / Inclusion / Inheritance | |
Instance Chain:
self,
::Comparable
|
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Inherits: | Object |
Defined in: | string.c, complex.c, encoding.c, pack.rb, rational.c, symbol.c, transcode.c |
Overview
A String object holds and manipulates an arbitrary sequence of bytes, typically representing characters. String
objects may be created using .new or as literals.
Because of aliasing issues, users of strings should be aware of the methods that modify the contents of a String
object. Typically, methods with names ending in “!” modify their receiver, while those without a “!” return a new String
. However, there are exceptions, such as #[]=.
Class Method Summary
-
.new(str = "") ⇒ String
constructor
Returns a new string object containing a copy of str.
-
.try_convert(obj) ⇒ String?
Try to convert obj into a
String
, using to_str method.
Instance Attribute Summary
-
#ascii_only? ⇒ Boolean
readonly
Returns true for a string which has only ASCII characters.
-
#empty? ⇒ Boolean
readonly
Returns
true
if str has a length of zero. -
#valid_encoding? ⇒ Boolean
readonly
Returns true for a string which is encoded correctly.
Instance Method Summary
-
#%(arg) ⇒ String
Format—Uses str as a format specification, and returns the result of applying it to arg.
-
#*(integer) ⇒ String
Copy — Returns a new
String
containinginteger
copies of the receiver. -
#+(other_str) ⇒ String
Concatenation—Returns a new
String
containing other_str concatenated to str. -
#+ ⇒ str (mutable)
If the string is frozen, then return duplicated mutable string.
-
#- ⇒ str (frozen)
Returns a frozen, possibly pre-existing copy of the string.
-
#<<(obj) ⇒ String
Appends the given object to str.
-
#<=>(other_string) ⇒ 1, ...
Comparison—Returns -1, 0, +1, or
nil
depending on whetherstring
is less than, equal to, or greater thanother_string
. -
#==(obj) ⇒ Boolean
(also: #===)
Equality—Returns whether
str
==obj
, similar toObject#==
. -
#===(obj) ⇒ Boolean
Alias for #==.
-
#=~(obj) ⇒ Integer?
Match—If obj is a
::Regexp
, use it as a pattern to match against str,and returns the position the match starts, ornil
if there is no match. -
#[](index) ⇒ String?
(also: #slice)
Element Reference — If passed a single #index, returns a substring of one character at that index.
-
#[]=(integer, new_str)
Element Assignment—Replaces some or all of the content of str.
-
#b ⇒ String
Returns a copied string whose encoding is ASCII-8BIT.
-
#bytes ⇒ Array
Returns an array of bytes in str.
-
#bytesize ⇒ Integer
Returns the length of
str
in bytes. -
#byteslice(integer) ⇒ String?
Byte Reference—If passed a single
::Integer
, returns a substring of one byte at that position. -
#capitalize ⇒ String
Returns a copy of str with the first character converted to uppercase and the remainder to lowercase.
-
#capitalize! ⇒ String?
Modifies str by converting the first character to uppercase and the remainder to lowercase.
-
#casecmp(other_str) ⇒ 1, ...
Case-insensitive version of #<=>.
-
#casecmp?(other_str) ⇒ true, ...
Returns
true
ifstr
andother_str
are equal after Unicode case folding,false
if they are not equal. -
#center(width, padstr = ' ') ⇒ String
Centers
str
inwidth
. -
#chars ⇒ Array
Returns an array of characters in str.
-
#chomp(separator = $/) ⇒ String
Returns a new
String
with the given record separator removed from the end of str (if present). -
#chomp!(separator = $/) ⇒ String?
Modifies str in place as described for #chomp, returning str, or
nil
if no modifications were made. -
#chop ⇒ String
Returns a new
String
with the last character removed. -
#chop! ⇒ String?
Processes str as for #chop, returning str, or
nil
if str is the empty string. -
#chr ⇒ String
Returns a one-character string at the beginning of the string.
-
#clear ⇒ String
Makes string empty.
-
#codepoints ⇒ Array
Returns an array of the
::Integer
ordinals of the characters in str. -
#concat(obj1, obj2, ...) ⇒ String
Concatenates the given object(s) to str.
-
#count([other_str]+) ⇒ Integer
Each
other_str
parameter defines a set of characters to count. -
#crypt(salt_str) ⇒ String
Returns the string generated by calling
crypt(3)
standard library function withstr
andsalt_str
, in this order, as its arguments. -
#delete([other_str]+) ⇒ String
Returns a copy of str with all characters in the intersection of its arguments deleted.
-
#delete!([other_str]+) ⇒ String?
Performs a #delete operation in place, returning str, or
nil
if str was not modified. -
#delete_prefix(prefix) ⇒ String
Returns a copy of str with leading
prefix
deleted. -
#delete_prefix!(prefix) ⇒ self?
Deletes leading
prefix
from str, returningnil
if no change was made. -
#delete_suffix(suffix) ⇒ String
Returns a copy of str with trailing
suffix
deleted. -
#delete_suffix!(suffix) ⇒ self?
Deletes trailing
suffix
from str, returningnil
if no change was made. -
#downcase ⇒ String
Returns a copy of str with all uppercase letters replaced with their lowercase counterparts.
-
#downcase! ⇒ String?
Downcases the contents of str, returning
nil
if no changes were made. -
#dump ⇒ String
Returns a quoted version of the string with all non-printing characters replaced by
\xHH
notation and all special characters escaped. -
#each_byte {|integer| ... } ⇒ String
Passes each byte in str to the given block, or returns an enumerator if no block is given.
-
#each_char {|cstr| ... } ⇒ String
Passes each character in str to the given block, or returns an enumerator if no block is given.
-
#each_codepoint {|integer| ... } ⇒ String
Passes the
::Integer
ordinal of each character in str, also known as a codepoint when applied to Unicode strings to the given block. -
#each_grapheme_cluster {|cstr| ... } ⇒ String
Passes each grapheme cluster in str to the given block, or returns an enumerator if no block is given.
-
#each_line(separator = $/, chomp: false) {|substr| ... } ⇒ String
Splits str using the supplied parameter as the record separator (
$/
by default), passing each substring in turn to the supplied block. -
#encode(encoding [, options] ) ⇒ String
The first form returns a copy of
str
transcoded to encoding #encoding. -
#encode!(encoding [, options] ) ⇒ String
The first form transcodes the contents of str from str.encoding to #encoding.
-
#encoding ⇒ Encoding
Alias for Regexp#encoding.
-
#end_with?([suffixes]+) ⇒ Boolean
Returns true if
str
ends with one of thesuffixes
given. -
#eql?(other) ⇒ Boolean
Two strings are equal if they have the same length and content.
-
#force_encoding(encoding) ⇒ String
Changes the encoding to #encoding and returns self.
- #freeze
-
#getbyte(index) ⇒ 0 .. 255
returns the indexth byte as an integer.
-
#grapheme_clusters ⇒ Array
Returns an array of grapheme clusters in str.
-
#gsub(pattern, replacement) ⇒ String
Returns a copy of str with all occurrences of pattern substituted for the second argument.
-
#gsub!(pattern, replacement) ⇒ String?
Performs the substitutions of #gsub in place, returning str, or
nil
if no substitutions were performed. -
#hash ⇒ Integer
Returns a hash based on the string’s length, content and encoding.
-
#hex ⇒ Integer
Treats leading characters from str as a string of hexadecimal digits (with an optional sign and an optional
0x
) and returns the corresponding number. -
#include?(other_str) ⇒ Boolean
Returns
true
if str contains the given string or character. -
#index(substring [, offset]) ⇒ Integer?
Returns the index of the first occurrence of the given substring or pattern (regexp) in str.
-
#initialize_copy(other_str) ⇒ String
Alias for #replace.
-
#insert(index, other_str) ⇒ String
Inserts other_str before the character at the given index, modifying str.
-
#inspect ⇒ String
Returns a printable version of str, surrounded by quote marks, with special characters escaped.
-
#intern ⇒ Symbol
(also: #to_sym)
Returns the
::Symbol
corresponding to str, creating the symbol if it did not previously exist. -
#length ⇒ Integer
(also: #size)
Returns the character length of str.
-
#lines(separator = $/, chomp: false) ⇒ Array
Returns an array of lines in str split using the supplied record separator (
$/
by default). -
#ljust(integer, padstr = ' ') ⇒ String
If integer is greater than the length of str, returns a new
String
of length integer with str left justified and padded with padstr; otherwise, returns str. -
#lstrip ⇒ String
Returns a copy of the receiver with leading whitespace removed.
-
#lstrip! ⇒ self?
Removes leading whitespace from the receiver.
-
#match(pattern) ⇒ MatchData?
Converts pattern to a
::Regexp
(if it isn’t already one), then invokes itsmatch
method on str. -
#match?(pattern) ⇒ Boolean
Converts pattern to a
::Regexp
(if it isn’t already one), then returns atrue
orfalse
indicates whether the regexp is matched str or not without updating$~
and other related variables. -
#next ⇒ String
(also: #succ)
Returns the successor to str.
-
#next! ⇒ String
(also: #succ!)
Equivalent to #succ, but modifies the receiver in place.
-
#oct ⇒ Integer
Treats leading characters of str as a string of octal digits (with an optional sign) and returns the corresponding number.
-
#ord ⇒ Integer
Returns the
::Integer
ordinal of a one-character string. -
#partition(sep) ⇒ Array, ...
Searches sep or pattern (regexp) in the string and returns the part before it, the match, and the part after it.
-
#prepend(other_str1, other_str2, ...) ⇒ String
Prepend—Prepend the given strings to str.
-
#replace(other_str) ⇒ String
(also: #initialize_copy)
Replaces the contents of str with the corresponding values in other_str.
-
#reverse ⇒ String
Returns a new string with the characters from str in reverse order.
-
#reverse! ⇒ String
Reverses str in place.
-
#rindex(substring [, integer]) ⇒ Integer?
Returns the index of the last occurrence of the given substring or pattern (regexp) in str.
-
#rjust(integer, padstr = ' ') ⇒ String
If integer is greater than the length of str, returns a new
String
of length integer with str right justified and padded with padstr; otherwise, returns str. -
#rpartition(sep) ⇒ Array, ...
Searches sep or pattern (regexp) in the string from the end of the string, and returns the part before it, the match, and the part after it.
-
#rstrip ⇒ String
Returns a copy of the receiver with trailing whitespace removed.
-
#rstrip! ⇒ self?
Removes trailing whitespace from the receiver.
-
#scan(pattern) ⇒ Array
Both forms iterate through str, matching the pattern (which may be a
::Regexp
or aString
). -
#scrub ⇒ String
If the string is invalid byte sequence then replace invalid bytes with given replacement character, else returns self.
-
#scrub! ⇒ String
If the string is invalid byte sequence then replace invalid bytes with given replacement character, else returns self.
-
#setbyte(index, integer) ⇒ Integer
modifies the indexth byte as integer.
-
#size ⇒ Integer
Alias for #length.
-
#slice(index) ⇒ String?
Alias for #[].
-
#slice!(integer) ⇒ String?
Deletes the specified portion from str, and returns the portion deleted.
-
#split(pattern = nil, [limit]) ⇒ Array
Divides str into substrings based on a delimiter, returning an array of these substrings.
-
#squeeze([other_str]*) ⇒ String
Builds a set of characters from the other_str parameter(s) using the procedure described for #count.
-
#squeeze!([other_str]*) ⇒ String?
Squeezes str in place, returning either str, or
nil
if no changes were made. -
#start_with?([prefixes]+) ⇒ Boolean
Returns true if
str
starts with one of theprefixes
given. -
#strip ⇒ String
Returns a copy of the receiver with leading and trailing whitespace removed.
-
#strip! ⇒ self?
Removes leading and trailing whitespace from the receiver.
-
#sub(pattern, replacement) ⇒ String
Returns a copy of
str
with the first occurrence ofpattern
replaced by the second argument. -
#sub!(pattern, replacement) ⇒ String?
Performs the same substitution as #sub in-place.
-
#succ ⇒ String
Alias for #next.
-
#succ! ⇒ String
Alias for #next!.
-
#sum(n = 16) ⇒ Integer
Returns a basic n-bit checksum of the characters in str, where n is the optional
::Integer
parameter, defaulting to 16. -
#swapcase ⇒ String
Returns a copy of str with uppercase alphabetic characters converted to lowercase and lowercase characters converted to uppercase.
-
#swapcase! ⇒ String?
Equivalent to #swapcase, but modifies the receiver in place, returning str, or
nil
if no changes were made. -
#to_c ⇒ Complex
Returns a complex which denotes the string form.
-
#to_f ⇒ Float
Returns the result of interpreting leading characters in str as a floating point number.
-
#to_i(base = 10) ⇒ Integer
Returns the result of interpreting leading characters in str as an integer base base (between 2 and 36).
-
#to_r ⇒ Rational
Returns the result of interpreting leading characters in
str
as a rational. -
#to_s ⇒ String
(also: #to_str)
Returns
self
. -
#to_str ⇒ String
Alias for #to_s.
-
#to_sym ⇒ Symbol
Alias for #intern.
-
#tr(from_str, to_str) ⇒ String
Returns a copy of
str
with the characters infrom_str
replaced by the corresponding characters in #to_str. -
#tr!(from_str, to_str) ⇒ String?
Translates str in place, using the same rules as #tr.
-
#tr_s(from_str, to_str) ⇒ String
Processes a copy of str as described under #tr, then removes duplicate characters in regions that were affected by the translation.
-
#tr_s!(from_str, to_str) ⇒ String?
Performs #tr_s processing on str in place, returning str, or
nil
if no changes were made. -
#undump ⇒ String
Returns an unescaped version of the string.
-
#unicode_normalize(form = :nfc)
Unicode Normalization—Returns a normalized form of
str
, using Unicode normalizations NFC, NFD, NFKC, or NFKD. -
#unicode_normalize!(form = :nfc)
Destructive version of #unicode_normalize, doing Unicode normalization in place.
-
#unicode_normalized?(form = :nfc)
Checks whether
str
is in Unicode normalization formform
, which can be any of the four values:nfc
,:nfd
,:nfkc
, or:nfkd
. -
#unpack(format) ⇒ Array
Decodes str (which may contain binary data) according to the format string, returning an array of each value extracted.
-
#unpack1(format) ⇒ Object
Decodes str (which may contain binary data) according to the format string, returning the first value extracted.
-
#upcase ⇒ String
Returns a copy of str with all lowercase letters replaced with their uppercase counterparts.
-
#upcase! ⇒ String?
Upcases the contents of str, returning
nil
if no changes were made. -
#upto(other_str, exclusive = false) {|s| ... } ⇒ String
Iterates through successive values, starting at str and ending at other_str inclusive, passing each value in turn to the block.
::Comparable
- Included
#< | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than 0. |
#<= | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than or equal to 0. |
#== | Compares two objects based on the receiver’s #<=> method, returning true if it returns 0. |
#> | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than 0. |
#>= | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than or equal to 0. |
#between? | |
#clamp |
Constructor Details
.new(str = "") ⇒ String
.new(str = "", encoding: enc) ⇒ String
.new(str = "", capacity: size) ⇒ String
String
.new(str = "", encoding: enc) ⇒ String
.new(str = "", capacity: size) ⇒ String
Returns a new string object containing a copy of str.
The optional encoding keyword argument specifies the encoding of the new string. If not specified, the encoding of str is used (or ASCII-8BIT, if str is not specified).
The optional capacity keyword argument specifies the size of the internal buffer. This may improve performance, when the string will be concatenated many times (causing many realloc calls).
# File 'string.c', line 1547
static VALUE rb_str_init(int argc, VALUE *argv, VALUE str) { static ID keyword_ids[2]; VALUE orig, opt, venc, vcapa; VALUE kwargs[2]; rb_encoding *enc = 0; int n; if (!keyword_ids[0]) { keyword_ids[0] = rb_id_encoding(); CONST_ID(keyword_ids[1], "capacity"); } n = rb_scan_args(argc, argv, "01:", &orig, &opt); if (!NIL_P(opt)) { rb_get_kwargs(opt, keyword_ids, 0, 2, kwargs); venc = kwargs[0]; vcapa = kwargs[1]; if (venc != Qundef && !NIL_P(venc)) { enc = rb_to_encoding(venc); } if (vcapa != Qundef && !NIL_P(vcapa)) { long capa = NUM2LONG(vcapa); long len = 0; int termlen = enc ? rb_enc_mbminlen(enc) : 1; if (capa < STR_BUF_MIN_SIZE) { capa = STR_BUF_MIN_SIZE; } if (n == 1) { StringValue(orig); len = RSTRING_LEN(orig); if (capa < len) { capa = len; } if (orig == str) n = 0; } str_modifiable(str); if (STR_EMBED_P(str)) { /* make noembed always */ char *new_ptr = ALLOC_N(char, (size_t)capa + termlen); memcpy(new_ptr, RSTRING(str)->as.ary, RSTRING_EMBED_LEN_MAX + 1); RSTRING(str)->as.heap.ptr = new_ptr; } else if (FL_TEST(str, STR_SHARED|STR_NOFREE)) { const size_t size = (size_t)capa + termlen; const char *const old_ptr = RSTRING_PTR(str); const size_t osize = RSTRING(str)->as.heap.len + TERM_LEN(str); char *new_ptr = ALLOC_N(char, (size_t)capa + termlen); memcpy(new_ptr, old_ptr, osize < size ? osize : size); FL_UNSET_RAW(str, STR_SHARED|STR_NOFREE); RSTRING(str)->as.heap.ptr = new_ptr; } else if (STR_HEAP_SIZE(str) != (size_t)capa + termlen) { SIZED_REALLOC_N(RSTRING(str)->as.heap.ptr, char, (size_t)capa + termlen, STR_HEAP_SIZE(str)); } RSTRING(str)->as.heap.len = len; TERM_FILL(&RSTRING(str)->as.heap.ptr[len], termlen); if (n == 1) { memcpy(RSTRING(str)->as.heap.ptr, RSTRING_PTR(orig), len); rb_enc_cr_str_exact_copy(str, orig); } FL_SET(str, STR_NOEMBED); RSTRING(str)->as.heap.aux.capa = capa; } else if (n == 1) { rb_str_replace(str, orig); } if (enc) { rb_enc_associate(str, enc); ENC_CODERANGE_CLEAR(str); } } else if (n == 1) { rb_str_replace(str, orig); } return str; }
Class Method Details
.try_convert(obj) ⇒ String
?
Try to convert obj into a String
, using to_str method. Returns converted string or nil if obj cannot be converted for any reason.
String.try_convert("str") #=> "str"
String.try_convert(/re/) #=> nil
# File 'string.c', line 2331
static VALUE rb_str_s_try_convert(VALUE dummy, VALUE str) { return rb_check_string_type(str); }
Instance Attribute Details
#ascii_only? ⇒ Boolean
(readonly)
Returns true for a string which has only ASCII characters.
"abc".force_encoding("UTF-8").ascii_only? #=> true
"abc\u{6666}".force_encoding("UTF-8").ascii_only? #=> false
# File 'string.c', line 10162
static VALUE rb_str_is_ascii_only_p(VALUE str) { int cr = rb_enc_str_coderange(str); return cr == ENC_CODERANGE_7BIT ? Qtrue : Qfalse; }
#empty? ⇒ Boolean
(readonly)
Returns true
if str has a length of zero.
"hello".empty? #=> false
" ".empty? #=> false
"".empty? #=> true
# File 'string.c', line 1875
static VALUE rb_str_empty(VALUE str) { if (RSTRING_LEN(str) == 0) return Qtrue; return Qfalse; }
#valid_encoding? ⇒ Boolean
(readonly)
Returns true for a string which is encoded correctly.
"\xc2\xa1".force_encoding("UTF-8").valid_encoding? #=> true
"\xc2".force_encoding("UTF-8").valid_encoding? #=> false
"\x80".force_encoding("UTF-8").valid_encoding? #=> false
# File 'string.c', line 10144
static VALUE rb_str_valid_encoding_p(VALUE str) { int cr = rb_enc_str_coderange(str); return cr == ENC_CODERANGE_BROKEN ? Qfalse : Qtrue; }
Instance Method Details
#%(arg) ⇒ String
Format—Uses str as a format specification, and returns the result of applying it to arg. If the format specification contains more than one substitution, then arg must be an ::Array
or ::Hash
containing the values to be substituted. See Kernel.sprintf for details of the format string.
"%05d" % 123 #=> "00123"
"%-5s: %016x" % [ "ID", self.object_id ] #=> "ID : 00002b054ec93168"
"foo = %{foo}" % { :foo => 'bar' } #=> "foo = bar"
# File 'string.c', line 2035
static VALUE rb_str_format_m(VALUE str, VALUE arg) { VALUE tmp = rb_check_array_type(arg); if (!NIL_P(tmp)) { return rb_str_format(RARRAY_LENINT(tmp), RARRAY_CONST_PTR(tmp), str); } return rb_str_format(1, &arg, str); }
#*(integer) ⇒ String
Copy — Returns a new String
containing integer
copies of the receiver. integer
must be greater than or equal to 0.
"Ho! " * 3 #=> "Ho! Ho! Ho! "
"Ho! " * 0 #=> ""
# File 'string.c', line 1965
VALUE rb_str_times(VALUE str, VALUE times) { VALUE str2; long n, len; char *ptr2; int termlen; if (times == INT2FIX(1)) { return rb_str_dup(str); } if (times == INT2FIX(0)) { str2 = str_alloc(rb_obj_class(str)); rb_enc_copy(str2, str); return str2; } len = NUM2LONG(times); if (len < 0) { rb_raise(rb_eArgError, "negative argument"); } if (RSTRING_LEN(str) == 1 && RSTRING_PTR(str)[0] == 0) { str2 = str_alloc(rb_obj_class(str)); if (!STR_EMBEDDABLE_P(len, 1)) { RSTRING(str2)->as.heap.aux.capa = len; RSTRING(str2)->as.heap.ptr = ZALLOC_N(char, (size_t)len + 1); STR_SET_NOEMBED(str2); } STR_SET_LEN(str2, len); rb_enc_copy(str2, str); return str2; } if (len && LONG_MAX/len < RSTRING_LEN(str)) { rb_raise(rb_eArgError, "argument too big"); } len *= RSTRING_LEN(str); termlen = TERM_LEN(str); str2 = str_new0(rb_obj_class(str), 0, len, termlen); ptr2 = RSTRING_PTR(str2); if (len) { n = RSTRING_LEN(str); memcpy(ptr2, RSTRING_PTR(str), n); while (n <= len/2) { memcpy(ptr2 + n, ptr2, n); n *= 2; } memcpy(ptr2 + n, ptr2, len-n); } STR_SET_LEN(str2, len); TERM_FILL(&ptr2[len], termlen); rb_enc_cr_str_copy_for_substr(str2, str); return str2; }
#+(other_str) ⇒ String
Concatenation—Returns a new String
containing other_str concatenated to str.
"Hello from " + self.to_s #=> "Hello from main"
# File 'string.c', line 1893
VALUE rb_str_plus(VALUE str1, VALUE str2) { VALUE str3; rb_encoding *enc; char *ptr1, *ptr2, *ptr3; long len1, len2; int termlen; StringValue(str2); enc = rb_enc_check_str(str1, str2); RSTRING_GETMEM(str1, ptr1, len1); RSTRING_GETMEM(str2, ptr2, len2); termlen = rb_enc_mbminlen(enc); if (len1 > LONG_MAX - len2) { rb_raise(rb_eArgError, "string size too big"); } str3 = str_new0(rb_cString, 0, len1+len2, termlen); ptr3 = RSTRING_PTR(str3); memcpy(ptr3, ptr1, len1); memcpy(ptr3+len1, ptr2, len2); TERM_FILL(&ptr3[len1+len2], termlen); ENCODING_CODERANGE_SET(str3, rb_enc_to_index(enc), ENC_CODERANGE_AND(ENC_CODERANGE(str1), ENC_CODERANGE(str2))); RB_GC_GUARD(str1); RB_GC_GUARD(str2); return str3; }
#+ ⇒ str
(mutable
)
If the string is frozen, then return duplicated mutable string.
If the string is not frozen, then return the string itself.
# File 'string.c', line 2632
static VALUE str_uplus(VALUE str) { if (OBJ_FROZEN(str)) { return rb_str_dup(str); } else { return str; } }
#- ⇒ str
(frozen
)
Returns a frozen, possibly pre-existing copy of the string.
The string will be deduplicated as long as it does not have any instance variables set on it.
# File 'string.c', line 2652
static VALUE str_uminus(VALUE str) { if (!BARE_STRING_P(str) && !rb_obj_frozen_p(str)) { str = rb_str_dup(str); } return rb_fstring(str); }
#<<(obj) ⇒ String
#<<(integer) ⇒ String
String
#<<(integer) ⇒ String
# File 'string.c', line 3064
VALUE rb_str_concat(VALUE str1, VALUE str2) { unsigned int code; rb_encoding *enc = STR_ENC_GET(str1); int encidx; if (RB_INTEGER_TYPE_P(str2)) { if (rb_num_to_uint(str2, &code) == 0) { } else if (FIXNUM_P(str2)) { rb_raise(rb_eRangeError, "%ld out of char range", FIX2LONG(str2)); } else { rb_raise(rb_eRangeError, "bignum out of char range"); } } else { return rb_str_append(str1, str2); } encidx = rb_enc_to_index(enc); if (encidx == ENCINDEX_ASCII || encidx == ENCINDEX_US_ASCII) { /* US-ASCII automatically extended to ASCII-8BIT */ char buf[1]; buf[0] = (char)code; if (code > 0xFF) { rb_raise(rb_eRangeError, "%u out of char range", code); } rb_str_cat(str1, buf, 1); if (encidx == ENCINDEX_US_ASCII && code > 127) { rb_enc_associate_index(str1, ENCINDEX_ASCII); ENC_CODERANGE_SET(str1, ENC_CODERANGE_VALID); } } else { long pos = RSTRING_LEN(str1); int cr = ENC_CODERANGE(str1); int len; char *buf; switch (len = rb_enc_codelen(code, enc)) { case ONIGERR_INVALID_CODE_POINT_VALUE: rb_raise(rb_eRangeError, "invalid codepoint 0x%X in %s", code, rb_enc_name(enc)); break; case ONIGERR_TOO_BIG_WIDE_CHAR_VALUE: case 0: rb_raise(rb_eRangeError, "%u out of char range", code); break; } buf = ALLOCA_N(char, len + 1); rb_enc_mbcput(code, buf, enc); if (rb_enc_precise_mbclen(buf, buf + len + 1, enc) != len) { rb_raise(rb_eRangeError, "invalid codepoint 0x%X in %s", code, rb_enc_name(enc)); } rb_str_resize(str1, pos+len); memcpy(RSTRING_PTR(str1) + pos, buf, len); if (cr == ENC_CODERANGE_7BIT && code > 127) cr = ENC_CODERANGE_VALID; ENC_CODERANGE_SET(str1, cr); } return str1; }
#<=>(other_string) ⇒ 1
, ...
Comparison—Returns -1, 0, +1, or nil
depending on whether string
is less than, equal to, or greater than other_string
.
nil
is returned if the two values are incomparable.
If the strings are of different lengths, and the strings are equal when compared up to the shortest length, then the longer string is considered greater than the shorter one.
<=>
is the basis for the methods <
, <=
, >
, >=
, and between?
, included from module ::Comparable
. The method #== does not use Comparable#==.
"abcdef" <=> "abcde" #=> 1
"abcdef" <=> "abcdef" #=> 0
"abcdef" <=> "abcdefg" #=> -1
"abcdef" <=> "ABCDEF" #=> 1
"abcdef" <=> 1 #=> nil
# File 'string.c', line 3319
static VALUE rb_str_cmp_m(VALUE str1, VALUE str2) { int result; VALUE s = rb_check_string_type(str2); if (NIL_P(s)) { return rb_invcmp(str1, str2); } result = rb_str_cmp(str1, s); return INT2FIX(result); }
#==(obj) ⇒ Boolean
#===(obj) ⇒ Boolean
Also known as: #===
Boolean
#===(obj) ⇒ Boolean
# File 'string.c', line 3266
VALUE rb_str_equal(VALUE str1, VALUE str2) { if (str1 == str2) return Qtrue; if (!RB_TYPE_P(str2, T_STRING)) { if (!rb_respond_to(str2, idTo_str)) { return Qfalse; } return rb_equal(str2, str1); } return rb_str_eql_internal(str1, str2); }
#==(obj) ⇒ Boolean
#===(obj) ⇒ Boolean
Boolean
#===(obj) ⇒ Boolean
Alias for #==.
#=~(obj) ⇒ Integer?
Match—If obj is a ::Regexp
, use it as a pattern to match against str,and returns the position the match starts, or nil
if there is no match. Otherwise, invokes obj.=~, passing str as an argument. The default =~
in ::Object
returns nil
.
Note: str =~ regexp
is not the same as regexp =~ str
. Strings captured from named capture groups are assigned to local variables only in the second case.
"cat o' 9 tails" =~ /\d/ #=> 7
"cat o' 9 tails" =~ 9 #=> nil
# File 'string.c', line 3787
static VALUE rb_str_match(VALUE x, VALUE y) { if (SPECIAL_CONST_P(y)) goto generic; switch (BUILTIN_TYPE(y)) { case T_STRING: rb_raise(rb_eTypeError, "type mismatch: String given"); case T_REGEXP: return rb_reg_match(y, x); generic: default: return rb_funcall(y, idEqTilde, 1, x); } }
#[](index) ⇒ String
?
#[](start, length) ⇒ String
?
#[](range) ⇒ String
?
#[](regexp) ⇒ String
?
#[](regexp, capture) ⇒ String
?
#[](match_str) ⇒ String
?
#slice(index) ⇒ String
?
#slice(start, length) ⇒ String
?
#slice(range) ⇒ String
?
#slice(regexp) ⇒ String
?
#slice(regexp, capture) ⇒ String
?
#slice(match_str) ⇒ String
?
Also known as: #slice
String
?
#[](start, length) ⇒ String
?
#[](range) ⇒ String
?
#[](regexp) ⇒ String
?
#[](regexp, capture) ⇒ String
?
#[](match_str) ⇒ String
?
#slice(index) ⇒ String
?
#slice(start, length) ⇒ String
?
#slice(range) ⇒ String
?
#slice(regexp) ⇒ String
?
#slice(regexp, capture) ⇒ String
?
#slice(match_str) ⇒ String
?
Element Reference — If passed a single #index, returns a substring of one character at that index. If passed a start
index and a #length, returns a substring containing #length characters starting at the start
index. If passed a range
, its beginning and end are interpreted as offsets delimiting the substring to be returned.
In these three cases, if an index is negative, it is counted from the end of the string. For the start
and range
cases the starting index is just before a character and an index matching the string’s size. Additionally, an empty string is returned when the starting index for a character range is at the end of the string.
Returns nil
if the initial index falls outside the string or the length is negative.
If a ::Regexp
is supplied, the matching portion of the string is returned. If a capture
follows the regular expression, which may be a capture group index or name, follows the regular expression that component of the ::MatchData
is returned instead.
If a match_str
is given, that string is returned if it occurs in the string.
Returns nil
if the regular expression does not match or the match string cannot be found.
a = "hello there"
a[1] #=> "e"
a[2, 3] #=> "llo"
a[2..3] #=> "ll"
a[-3, 2] #=> "er"
a[7..-2] #=> "her"
a[-4..-2] #=> "her"
a[-2..-4] #=> ""
a[11, 0] #=> ""
a[11] #=> nil
a[12, 0] #=> nil
a[12..-1] #=> nil
a[/[aeiou](.)\1/] #=> "ell"
a[/[aeiou](.)\1/, 0] #=> "ell"
a[/[aeiou](.)\1/, 1] #=> "l"
a[/[aeiou](.)\1/, 2] #=> nil
a[/(?<vowel>[aeiou])(?<non_vowel>[^aeiou])/, "non_vowel"] #=> "l"
a[/(?<vowel>[aeiou])(?<non_vowel>[^aeiou])/, "vowel"] #=> "e"
a["lo"] #=> "lo"
a["bye"] #=> nil
# File 'string.c', line 4555
static VALUE rb_str_aref_m(int argc, VALUE *argv, VALUE str) { if (argc == 2) { if (RB_TYPE_P(argv[0], T_REGEXP)) { return rb_str_subpat(str, argv[0], argv[1]); } else { long beg = NUM2LONG(argv[0]); long len = NUM2LONG(argv[1]); return rb_str_substr(str, beg, len); } } rb_check_arity(argc, 1, 2); return rb_str_aref(str, argv[0]); }
#[]=(integer, new_str)
#[]=(integer, integer, new_str)
#[]=(range, aString)
#[]=(regexp, new_str)
#[]=(regexp, integer, new_str)
#[]=(regexp, name, new_str)
#[]=(other_str, new_str)
Element Assignment—Replaces some or all of the content of str. The portion of the string affected is determined using the same criteria as #[]. If the replacement string is not the same length as the text it is replacing, the string will be adjusted accordingly. If the regular expression or string is used as the index doesn’t match a position in the string, ::IndexError
is raised. If the regular expression form is used, the optional second ::Integer
allows you to specify which portion of the match to replace (effectively using the ::MatchData
indexing rules. The forms that take an ::Integer
will raise an ::IndexError
if the value is out of range; the ::Range
form will raise a ::RangeError
, and the ::Regexp
and String
will raise an ::IndexError
on negative match.
# File 'string.c', line 4793
static VALUE rb_str_aset_m(int argc, VALUE *argv, VALUE str) { if (argc == 3) { if (RB_TYPE_P(argv[0], T_REGEXP)) { rb_str_subpat_set(str, argv[0], argv[1], argv[2]); } else { rb_str_splice(str, NUM2LONG(argv[0]), NUM2LONG(argv[1]), argv[2]); } return argv[2]; } rb_check_arity(argc, 2, 3); return rb_str_aset(str, argv[0], argv[1]); }
#b ⇒ String
Returns a copied string whose encoding is ASCII-8BIT.
# File 'string.c', line 10124
static VALUE rb_str_b(VALUE str) { VALUE str2 = str_alloc(rb_cString); str_replace_shared_without_enc(str2, str); ENC_CODERANGE_CLEAR(str2); return str2; }
#bytes ⇒ Array
Returns an array of bytes in str. This is a shorthand for str.each_byte.to_a
.
If a block is given, which is a deprecated form, works the same as #each_byte.
# File 'string.c', line 8423
static VALUE rb_str_bytes(VALUE str) { VALUE ary = WANTARRAY("bytes", RSTRING_LEN(str)); return rb_str_enumerate_bytes(str, ary); }
#bytesize ⇒ Integer
Returns the length of str
in bytes.
"\x80\u3042".bytesize #=> 4
"hello".bytesize #=> 5
# File 'string.c', line 1858
static VALUE rb_str_bytesize(VALUE str) { return LONG2NUM(RSTRING_LEN(str)); }
#byteslice(integer) ⇒ String
?
#byteslice(integer, integer) ⇒ String
?
#byteslice(range) ⇒ String
?
String
?
#byteslice(integer, integer) ⇒ String
?
#byteslice(range) ⇒ String
?
Byte Reference—If passed a single ::Integer
, returns a substring of one byte at that position. If passed two ::Integer
objects, returns a substring starting at the offset given by the first, and a length given by the second. If given a ::Range
, a substring containing bytes at offsets given by the range is returned. In all three cases, if an offset is negative, it is counted from the end of str. Returns nil
if the initial offset falls outside the string, the length is negative, or the beginning of the range is greater than the end. The encoding of the resulted string keeps original encoding.
"hello".byteslice(1) #=> "e"
"hello".byteslice(-1) #=> "o"
"hello".byteslice(1, 2) #=> "el"
"\x80\u3042".byteslice(1, 3) #=> "\u3042"
"\x03\u3042\xff".byteslice(1..3) #=> "\u3042"
# File 'string.c', line 5596
static VALUE rb_str_byteslice(int argc, VALUE *argv, VALUE str) { if (argc == 2) { long beg = NUM2LONG(argv[0]); long end = NUM2LONG(argv[1]); return str_byte_substr(str, beg, end, TRUE); } rb_check_arity(argc, 1, 2); return str_byte_aref(str, argv[0]); }
#capitalize ⇒ String
#capitalize([options]) ⇒ String
String
#capitalize([options]) ⇒ String
Returns a copy of str with the first character converted to uppercase and the remainder to lowercase.
See #downcase for meaning of options
and use with different encodings.
"hello".capitalize #=> "Hello"
"HELLO".capitalize #=> "Hello"
"123ABC".capitalize #=> "123abc"
# File 'string.c', line 6901
static VALUE rb_str_capitalize(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE | ONIGENC_CASE_TITLECASE; VALUE ret; flags = check_case_options(argc, argv, flags); enc = str_true_enc(str); if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return str; if (flags&ONIGENC_CASE_ASCII_ONLY) { ret = rb_str_new_with_class(str, 0, RSTRING_LEN(str)); rb_str_ascii_casemap(str, ret, &flags, enc); } else { ret = rb_str_casemap(str, &flags, enc); } return ret; }
#capitalize! ⇒ String
?
#capitalize!([options]) ⇒ String
?
String
?
#capitalize!([options]) ⇒ String
?
Modifies str by converting the first character to uppercase and the remainder to lowercase. Returns nil
if no changes are made. There is an exception for modern Georgian (mkhedruli/MTAVRULI), where the result is the same as for #downcase, to avoid mixed case.
See #downcase for meaning of options
and use with different encodings.
a = "hello"
a.capitalize! #=> "Hello"
a #=> "Hello"
a.capitalize! #=> nil
# File 'string.c', line 6866
static VALUE rb_str_capitalize_bang(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE | ONIGENC_CASE_TITLECASE; flags = check_case_options(argc, argv, flags); str_modify_keep_cr(str); enc = str_true_enc(str); if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return Qnil; if (flags&ONIGENC_CASE_ASCII_ONLY) rb_str_ascii_casemap(str, str, &flags, enc); else str_shared_replace(str, rb_str_casemap(str, &flags, enc)); if (ONIGENC_CASE_MODIFIED&flags) return str; return Qnil; }
#casecmp(other_str) ⇒ 1
, ...
Case-insensitive version of #<=>. Currently, case-insensitivity only works on characters A-Z/a-z, not all of Unicode. This is different from #casecmp?.
"aBcDeF".casecmp("abcde") #=> 1
"aBcDeF".casecmp("abcdef") #=> 0
"aBcDeF".casecmp("abcdefg") #=> -1
"abcdef".casecmp("ABCDEF") #=> 0
nil
is returned if the two strings have incompatible encodings, or if other_str
is not a string.
"foo".casecmp(2) #=> nil
"\u{e4 f6 fc}".encode("ISO-8859-1").casecmp("\u{c4 d6 dc}") #=> nil
# File 'string.c', line 3354
static VALUE rb_str_casecmp(VALUE str1, VALUE str2) { VALUE s = rb_check_string_type(str2); if (NIL_P(s)) { return Qnil; } return str_casecmp(str1, s); }
#casecmp?(other_str) ⇒ true
, ...
Returns true
if str
and other_str
are equal after Unicode case folding, false
if they are not equal.
"aBcDeF".casecmp?("abcde") #=> false
"aBcDeF".casecmp?("abcdef") #=> true
"aBcDeF".casecmp?("abcdefg") #=> false
"abcdef".casecmp?("ABCDEF") #=> true
"\u{e4 f6 fc}".casecmp?("\u{c4 d6 dc}") #=> true
nil
is returned if the two strings have incompatible encodings, or if other_str
is not a string.
"foo".casecmp?(2) #=> nil
"\u{e4 f6 fc}".encode("ISO-8859-1").casecmp?("\u{c4 d6 dc}") #=> nil
# File 'string.c', line 3441
static VALUE rb_str_casecmp_p(VALUE str1, VALUE str2) { VALUE s = rb_check_string_type(str2); if (NIL_P(s)) { return Qnil; } return str_casecmp_p(str1, s); }
#center(width, padstr = ' ') ⇒ String
Centers str
in width
. If width
is greater than the length of str
, returns a new String
of length width
with str
centered and padded with padstr
; otherwise, returns str
.
"hello".center(4) #=> "hello"
"hello".center(20) #=> " hello "
"hello".center(20, '123') #=> "1231231hello12312312"
# File 'string.c', line 9744
static VALUE rb_str_center(int argc, VALUE *argv, VALUE str) { return rb_str_justify(argc, argv, str, 'c'); }
#chars ⇒ Array
Returns an array of characters in str. This is a shorthand for str.each_char.to_a
.
If a block is given, which is a deprecated form, works the same as #each_char.
# File 'string.c', line 8501
static VALUE rb_str_chars(VALUE str) { VALUE ary = WANTARRAY("chars", rb_str_strlen(str)); return rb_str_enumerate_chars(str, ary); }
#chomp(separator = $/) ⇒ String
Returns a new String
with the given record separator removed from the end of str (if present). If $/
has not been changed from the default Ruby record separator, then chomp
also removes carriage return characters (that is it will remove \n
, \r
, and \r\n
). If $/
is an empty string, it will remove all trailing newlines from the string.
"hello".chomp #=> "hello"
"hello\n".chomp #=> "hello"
"hello\r\n".chomp #=> "hello"
"hello\n\r".chomp #=> "hello\n"
"hello\r".chomp #=> "hello"
"hello \n there".chomp #=> "hello \n there"
"hello".chomp("llo") #=> "he"
"hello\r\n\r\n".chomp('') #=> "hello"
"hello\r\n\r\r\n".chomp('') #=> "hello\r\n\r"
# File 'string.c', line 8978
static VALUE rb_str_chomp(int argc, VALUE *argv, VALUE str) { VALUE rs = chomp_rs(argc, argv); if (NIL_P(rs)) return rb_str_dup(str); return rb_str_subseq(str, 0, chompped_length(str, rs)); }
#chomp!(separator = $/) ⇒ String
?
Modifies str in place as described for #chomp, returning str, or nil
if no modifications were made.
# File 'string.c', line 8944
static VALUE rb_str_chomp_bang(int argc, VALUE *argv, VALUE str) { VALUE rs; str_modifiable(str); if (RSTRING_LEN(str) == 0) return Qnil; rs = chomp_rs(argc, argv); if (NIL_P(rs)) return Qnil; return rb_str_chomp_string(str, rs); }
#chop ⇒ String
Returns a new String
with the last character removed. If the string ends with \r\n
, both characters are removed. Applying chop
to an empty string returns an empty string. #chomp is often a safer alternative, as it leaves the string unchanged if it doesn’t end in a record separator.
"string\r\n".chop #=> "string"
"string\n\r".chop #=> "string\n"
"string\n".chop #=> "string"
"string".chop #=> "strin"
"x".chop.chop #=> ""
# File 'string.c', line 8795
static VALUE rb_str_chop(VALUE str) { return rb_str_subseq(str, 0, chopped_length(str)); }
#chop! ⇒ String
?
[ GitHub ]
# File 'string.c', line 8759
static VALUE rb_str_chop_bang(VALUE str) { str_modify_keep_cr(str); if (RSTRING_LEN(str) > 0) { long len; len = chopped_length(str); STR_SET_LEN(str, len); TERM_FILL(&RSTRING_PTR(str)[len], TERM_LEN(str)); if (ENC_CODERANGE(str) != ENC_CODERANGE_7BIT) { ENC_CODERANGE_CLEAR(str); } return str; } return Qnil; }
#chr ⇒ String
Returns a one-character string at the beginning of the string.
a = "abcde"
a.chr #=> "a"
# File 'string.c', line 5407
static VALUE rb_str_chr(VALUE str) { return rb_str_substr(str, 0, 1); }
#clear ⇒ String
Makes string empty.
a = "abcde"
a.clear #=> ""
# File 'string.c', line 5383
static VALUE rb_str_clear(VALUE str) { str_discard(str); STR_SET_EMBED(str); STR_SET_EMBED_LEN(str, 0); RSTRING_PTR(str)[0] = 0; if (rb_enc_asciicompat(STR_ENC_GET(str))) ENC_CODERANGE_SET(str, ENC_CODERANGE_7BIT); else ENC_CODERANGE_SET(str, ENC_CODERANGE_VALID); return str; }
#codepoints ⇒ Array
Returns an array of the ::Integer
ordinals of the characters in str. This is a shorthand for str.each_codepoint.to_a
.
If a block is given, which is a deprecated form, works the same as #each_codepoint.
# File 'string.c', line 8576
static VALUE rb_str_codepoints(VALUE str) { VALUE ary = WANTARRAY("codepoints", rb_str_strlen(str)); return rb_str_enumerate_codepoints(str, ary); }
#concat(obj1, obj2, ...) ⇒ String
Concatenates the given object(s) to str. If an object is an ::Integer
, it is considered a codepoint and converted to a character before concatenation.
concat
can take multiple arguments, and all the arguments are concatenated in order.
a = "hello "
a.concat("world", 33) #=> "hello world!"
a #=> "hello world!"
b = "sn"
b.concat("_", b, "_", b) #=> "sn_sn_sn"
See also #<<, which takes a single argument.
# File 'string.c', line 3028
static VALUE rb_str_concat_multi(int argc, VALUE *argv, VALUE str) { str_modifiable(str); if (argc == 1) { return rb_str_concat(str, argv[0]); } else if (argc > 1) { int i; VALUE arg_str = rb_str_tmp_new(0); rb_enc_copy(arg_str, str); for (i = 0; i < argc; i++) { rb_str_concat(arg_str, argv[i]); } rb_str_buf_append(str, arg_str); } return str; }
#count([other_str]+) ⇒ Integer
Each other_str
parameter defines a set of characters to count. The intersection of these sets defines the characters to count in str
. Any other_str
that starts with a caret ^
is negated. The sequence c1-c2
means all characters between c1 and c2. The backslash character \
can be used to escape ^
or -
and is otherwise ignored unless it appears at the end of a sequence or the end of a other_str
.
a = "hello world"
a.count "lo" #=> 5
a.count "lo", "o" #=> 2
a.count "hello", "^l" #=> 4
a.count "ej-m" #=> 4
"hello^world".count "\\^aeiou" #=> 4
"hello-world".count "a\\-eo" #=> 4
c = "hello world\\r\\n"
c.count "\\" #=> 2
c.count "\\A" #=> 0
c.count "X-\\w" #=> 3
# File 'string.c', line 7709
static VALUE rb_str_count(int argc, VALUE *argv, VALUE str) { char table[TR_TABLE_SIZE]; rb_encoding *enc = 0; VALUE del = 0, nodel = 0, tstr; char *s, *send; int i; int ascompat; rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS); tstr = argv[0]; StringValue(tstr); enc = rb_enc_check(str, tstr); if (argc == 1) { const char *ptstr; if (RSTRING_LEN(tstr) == 1 && rb_enc_asciicompat(enc) && (ptstr = RSTRING_PTR(tstr), ONIGENC_IS_ALLOWED_REVERSE_MATCH(enc, (const unsigned char *)ptstr, (const unsigned char *)ptstr+1)) && !is_broken_string(str)) { int n = 0; int clen; unsigned char c = rb_enc_codepoint_len(ptstr, ptstr+1, &clen, enc); s = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return INT2FIX(0); send = RSTRING_END(str); while (s < send) { if (*(unsigned char*)s++ == c) n++; } return INT2NUM(n); } } tr_setup_table(tstr, table, TRUE, &del, &nodel, enc); for (i=1; i<argc; i++) { tstr = argv[i]; StringValue(tstr); enc = rb_enc_check(str, tstr); tr_setup_table(tstr, table, FALSE, &del, &nodel, enc); } s = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return INT2FIX(0); send = RSTRING_END(str); ascompat = rb_enc_asciicompat(enc); i = 0; while (s < send) { unsigned int c; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (table[c]) { i++; } s++; } else { int clen; c = rb_enc_codepoint_len(s, send, &clen, enc); if (tr_find(c, table, del, nodel)) { i++; } s += clen; } } return INT2NUM(i); }
#crypt(salt_str) ⇒ String
Returns the string generated by calling crypt(3)
standard library function with str
and salt_str
, in this order, as its arguments. Please do not use this method any longer. It is legacy; provided only for backward compatibility with ruby scripts in earlier days. It is bad to use in contemporary programs for several reasons:
-
Behaviour of C’s
crypt(3)
depends on the OS it is run. The generated string lacks data portability. -
On some OSes such as Mac OS,
crypt(3)
never fails (i.e. silently ends up in unexpected results). -
On some OSes such as Mac OS,
crypt(3)
is not thread safe. -
So-called “traditional” usage of
crypt(3)
is very very very weak. According to its manpage, Linux’s traditionalcrypt(3)
output has only 2**56 variations; too easy to brute force today. And this is the default behaviour. -
In order to make things robust some OSes implement so-called “modular” usage. To go through, you have to do a complex build-up of the
salt_str
parameter, by hand. Failure in generation of a proper salt string tends not to yield any errors; typos in parameters are normally not detectable.-
For instance, in the following example, the second invocation of String#crypt is wrong; it has a typo in “round=” (lacks “s”). However the call does not fail and something unexpected is generated.
"foo".crypt("$5$rounds=1000$salt$") # OK, proper usage "foo".crypt("$5$round=1000$salt$") # Typo not detected
-
-
Even in the “modular” mode, some hash functions are considered archaic and no longer recommended at all; for instance module
$1$
is officially abandoned by its author: see
phk.freebsd.dk/sagas/md5crypt_eol.html . For another
instance module <code>$3$</code> is considered completely
broken: see the manpage of FreeBSD.
-
On some OS such as Mac OS, there is no modular mode. Yet, as written above,
crypt(3)
on Mac OS never fails. This means even if you build up a proper salt string it generates a traditional DES hash anyways, and there is no way for you to be aware of."foo".crypt("$5$rounds=1000$salt$") # => "$5fNPQMxC5j6."
If for some reason you cannot migrate to other secure contemporary password hashing algorithms, install the string-crypt gem and require 'string/crypt'
to continue using it.
# File 'string.c', line 9460
static VALUE rb_str_crypt(VALUE str, VALUE salt) { #ifdef HAVE_CRYPT_R VALUE databuf; struct crypt_data *data; # define CRYPT_END() ALLOCV_END(databuf) #else extern char *crypt(const char *, const char *); # define CRYPT_END() (void)0 #endif VALUE result; const char *s, *saltp; char *res; #ifdef BROKEN_CRYPT char salt_8bit_clean[3]; #endif StringValue(salt); mustnot_wchar(str); mustnot_wchar(salt); if (RSTRING_LEN(salt) < 2) { short_salt: rb_raise(rb_eArgError, "salt too short (need >=2 bytes)"); } s = StringValueCStr(str); saltp = RSTRING_PTR(salt); if (!saltp[0] || !saltp[1]) goto short_salt; #ifdef BROKEN_CRYPT if (!ISASCII((unsigned char)saltp[0]) || !ISASCII((unsigned char)saltp[1])) { salt_8bit_clean[0] = saltp[0] & 0x7f; salt_8bit_clean[1] = saltp[1] & 0x7f; salt_8bit_clean[2] = '\0'; saltp = salt_8bit_clean; } #endif #ifdef HAVE_CRYPT_R data = ALLOCV(databuf, sizeof(struct crypt_data)); # ifdef HAVE_STRUCT_CRYPT_DATA_INITIALIZED data->initialized = 0; # endif res = crypt_r(s, saltp, data); #else res = crypt(s, saltp); #endif if (!res) { int err = errno; CRYPT_END(); rb_syserr_fail(err, "crypt"); } result = rb_str_new_cstr(res); CRYPT_END(); return result; }
#delete([other_str]+) ⇒ String
Returns a copy of str with all characters in the intersection of its arguments deleted. Uses the same rules for building the set of characters as #count.
"hello".delete "l","lo" #=> "heo"
"hello".delete "lo" #=> "he"
"hello".delete "aeiou", "^e" #=> "hell"
"hello".delete "ej-m" #=> "ho"
# File 'string.c', line 7528
static VALUE rb_str_delete(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_delete_bang(argc, argv, str); return str; }
#delete!([other_str]+) ⇒ String
?
Performs a #delete operation in place, returning str, or nil
if str was not modified.
# File 'string.c', line 7452
static VALUE rb_str_delete_bang(int argc, VALUE *argv, VALUE str) { char squeez[TR_TABLE_SIZE]; rb_encoding *enc = 0; char *s, *send, *t; VALUE del = 0, nodel = 0; int modify = 0; int i, ascompat, cr; if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return Qnil; rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS); for (i=0; i<argc; i++) { VALUE s = argv[i]; StringValue(s); enc = rb_enc_check(str, s); tr_setup_table(s, squeez, i==0, &del, &nodel, enc); } str_modify_keep_cr(str); ascompat = rb_enc_asciicompat(enc); s = t = RSTRING_PTR(str); send = RSTRING_END(str); cr = ascompat ? ENC_CODERANGE_7BIT : ENC_CODERANGE_VALID; while (s < send) { unsigned int c; int clen; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (squeez[c]) { modify = 1; } else { if (t != s) *t = c; t++; } s++; } else { c = rb_enc_codepoint_len(s, send, &clen, enc); if (tr_find(c, squeez, del, nodel)) { modify = 1; } else { if (t != s) rb_enc_mbcput(c, t, enc); t += clen; if (cr == ENC_CODERANGE_7BIT) cr = ENC_CODERANGE_VALID; } s += clen; } } TERM_FILL(t, TERM_LEN(str)); STR_SET_LEN(str, t - RSTRING_PTR(str)); ENC_CODERANGE_SET(str, cr); if (modify) return str; return Qnil; }
#delete_prefix(prefix) ⇒ String
Returns a copy of str with leading prefix
deleted.
"hello".delete_prefix("hel") #=> "lo"
"hello".delete_prefix("llo") #=> "hello"
# File 'string.c', line 9979
static VALUE rb_str_delete_prefix(VALUE str, VALUE prefix) { long prefixlen; prefixlen = deleted_prefix_length(str, prefix); if (prefixlen <= 0) return rb_str_dup(str); return rb_str_subseq(str, prefixlen, RSTRING_LEN(str) - prefixlen); }
#delete_prefix!(prefix) ⇒ self
?
Deletes leading prefix
from str, returning nil
if no change was made.
"hello".delete_prefix!("hel") #=> "lo"
"hello".delete_prefix!("llo") #=> nil
# File 'string.c', line 9957
static VALUE rb_str_delete_prefix_bang(VALUE str, VALUE prefix) { long prefixlen; str_modify_keep_cr(str); prefixlen = deleted_prefix_length(str, prefix); if (prefixlen <= 0) return Qnil; return rb_str_drop_bytes(str, prefixlen); }
#delete_suffix(suffix) ⇒ String
Returns a copy of str with trailing suffix
deleted.
"hello".delete_suffix("llo") #=> "he"
"hello".delete_suffix("hel") #=> "hello"
# File 'string.c', line 10065
static VALUE rb_str_delete_suffix(VALUE str, VALUE suffix) { long suffixlen; suffixlen = deleted_suffix_length(str, suffix); if (suffixlen <= 0) return rb_str_dup(str); return rb_str_subseq(str, 0, RSTRING_LEN(str) - suffixlen); }
#delete_suffix!(suffix) ⇒ self
?
Deletes trailing suffix
from str, returning nil
if no change was made.
"hello".delete_suffix!("llo") #=> "he"
"hello".delete_suffix!("hel") #=> nil
# File 'string.c', line 10035
static VALUE rb_str_delete_suffix_bang(VALUE str, VALUE suffix) { long olen, suffixlen, len; str_modifiable(str); suffixlen = deleted_suffix_length(str, suffix); if (suffixlen <= 0) return Qnil; olen = RSTRING_LEN(str); str_modify_keep_cr(str); len = olen - suffixlen; STR_SET_LEN(str, len); TERM_FILL(&RSTRING_PTR(str)[len], TERM_LEN(str)); if (ENC_CODERANGE(str) != ENC_CODERANGE_7BIT) { ENC_CODERANGE_CLEAR(str); } return str; }
#downcase ⇒ String
#downcase([options]) ⇒ String
String
#downcase([options]) ⇒ String
Returns a copy of str with all uppercase letters replaced with their lowercase counterparts. Which letters exactly are replaced, and by which other letters, depends on the presence or absence of options, and on the #encoding of the string.
The meaning of the options
is as follows:
- No option
-
Full Unicode case mapping, suitable for most languages (see :turkic and :lithuanian options below for exceptions). Context-dependent case mapping as described in Table 3-14 of the Unicode standard is currently not supported.
:ascii
-
Only the ASCII region, i.e. the characters “A” to “Z” and “a” to “z”, are affected. This option cannot be combined with any other option.
:turkic
-
Full Unicode case mapping, adapted for Turkic languages (Turkish, Azerbaijani, …). This means that upper case I is mapped to lower case dotless i, and so on.
:lithuanian
-
Currently, just full Unicode case mapping. In the future, full Unicode case mapping adapted for Lithuanian (keeping the dot on the lower case i even if there is an accent on top).
:fold
-
Only available on
downcase
anddowncase!
. Unicode case folding, which is more far-reaching than Unicode case mapping. This option currently cannot be combined with any other option (i.e. there is currently no variant for turkic languages).
Please note that several assumptions that are valid for ASCII-only case conversions do not hold for more general case conversions. For example, the length of the result may not be the same as the length of the input (neither in characters nor in bytes), some roundtrip assumptions (e.g. str.downcase == str.upcase.downcase) may not apply, and Unicode normalization (i.e. #unicode_normalize) is not necessarily maintained by case mapping operations.
Non-ASCII case mapping/folding is currently supported for UTF-8, UTF-16BE/LE, UTF-32BE/LE, and ISO-8859-1~16 Strings/Symbols. This support will be extended to other encodings.
"hEllO".downcase #=> "hello"
# File 'string.c', line 6822
static VALUE rb_str_downcase(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_DOWNCASE; VALUE ret; flags = check_case_options(argc, argv, flags); enc = str_true_enc(str); if (case_option_single_p(flags, enc, str)) { ret = rb_str_new_with_class(str, RSTRING_PTR(str), RSTRING_LEN(str)); str_enc_copy(ret, str); downcase_single(ret); } else if (flags&ONIGENC_CASE_ASCII_ONLY) { ret = rb_str_new_with_class(str, 0, RSTRING_LEN(str)); rb_str_ascii_casemap(str, ret, &flags, enc); } else { ret = rb_str_casemap(str, &flags, enc); } return ret; }
#downcase! ⇒ String
?
#downcase!([options]) ⇒ String
?
String
?
#downcase!([options]) ⇒ String
?
Downcases the contents of str, returning nil
if no changes were made.
See #downcase for meaning of options
and use with different encodings.
# File 'string.c', line 6749
static VALUE rb_str_downcase_bang(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_DOWNCASE; flags = check_case_options(argc, argv, flags); str_modify_keep_cr(str); enc = str_true_enc(str); if (case_option_single_p(flags, enc, str)) { if (downcase_single(str)) flags |= ONIGENC_CASE_MODIFIED; } else if (flags&ONIGENC_CASE_ASCII_ONLY) rb_str_ascii_casemap(str, str, &flags, enc); else str_shared_replace(str, rb_str_casemap(str, &flags, enc)); if (ONIGENC_CASE_MODIFIED&flags) return str; return Qnil; }
#dump ⇒ String
Returns a quoted version of the string with all non-printing characters replaced by \xHH
notation and all special characters escaped.
This method can be used for round-trip: if the resulting new_str
is eval’ed, it will produce the original string.
"hello \n ''".dump #=> "\"hello \\n ''\""
"\f\x00\xff\\\"".dump #=> "\"\\f\\x00\\xFF\\\\\\\"\""
See also #undump.
# File 'string.c', line 6041
VALUE rb_str_dump(VALUE str) { int encidx = rb_enc_get_index(str); rb_encoding *enc = rb_enc_from_index(encidx); long len; const char *p, *pend; char *q, *qend; VALUE result; int u8 = (encidx == rb_utf8_encindex()); static const char nonascii_suffix[] = ".dup.force_encoding(\"%s\")"; len = 2; /* "" */ if (!rb_enc_asciicompat(enc)) { len += strlen(nonascii_suffix) - rb_strlen_lit("%s"); len += strlen(enc->name); } p = RSTRING_PTR(str); pend = p + RSTRING_LEN(str); while (p < pend) { int clen; unsigned char c = *p++; switch (c) { case '"': case '\\': case '\n': case '\r': case '\t': case '\f': case '\013': case '\010': case '\007': case '\033': clen = 2; break; case '#': clen = IS_EVSTR(p, pend) ? 2 : 1; break; default: if (ISPRINT(c)) { clen = 1; } else { if (u8 && c > 0x7F) { /* \u notation */ int n = rb_enc_precise_mbclen(p-1, pend, enc); if (MBCLEN_CHARFOUND_P(n)) { unsigned int cc = rb_enc_mbc_to_codepoint(p-1, pend, enc); if (cc <= 0xFFFF) clen = 6; /* \uXXXX */ else if (cc <= 0xFFFFF) clen = 9; /* \u{XXXXX} */ else clen = 10; /* \u{XXXXXX} */ p += MBCLEN_CHARFOUND_LEN(n)-1; break; } } clen = 4; /* \xNN */ } break; } if (clen > LONG_MAX - len) { rb_raise(rb_eRuntimeError, "string size too big"); } len += clen; } result = rb_str_new_with_class(str, 0, len); p = RSTRING_PTR(str); pend = p + RSTRING_LEN(str); q = RSTRING_PTR(result); qend = q + len + 1; *q++ = '"'; while (p < pend) { unsigned char c = *p++; if (c == '"' || c == '\\') { *q++ = '\\'; *q++ = c; } else if (c == '#') { if (IS_EVSTR(p, pend)) *q++ = '\\'; *q++ = '#'; } else if (c == '\n') { *q++ = '\\'; *q++ = 'n'; } else if (c == '\r') { *q++ = '\\'; *q++ = 'r'; } else if (c == '\t') { *q++ = '\\'; *q++ = 't'; } else if (c == '\f') { *q++ = '\\'; *q++ = 'f'; } else if (c == '\013') { *q++ = '\\'; *q++ = 'v'; } else if (c == '\010') { *q++ = '\\'; *q++ = 'b'; } else if (c == '\007') { *q++ = '\\'; *q++ = 'a'; } else if (c == '\033') { *q++ = '\\'; *q++ = 'e'; } else if (ISPRINT(c)) { *q++ = c; } else { *q++ = '\\'; if (u8) { int n = rb_enc_precise_mbclen(p-1, pend, enc) - 1; if (MBCLEN_CHARFOUND_P(n)) { int cc = rb_enc_mbc_to_codepoint(p-1, pend, enc); p += n; if (cc <= 0xFFFF) snprintf(q, qend-q, "u%04X", cc); /* \uXXXX */ else snprintf(q, qend-q, "u{%X}", cc); /* \u{XXXXX} or \u{XXXXXX} */ q += strlen(q); continue; } } snprintf(q, qend-q, "x%02X", c); q += 3; } } *q++ = '"'; *q = '\0'; if (!rb_enc_asciicompat(enc)) { snprintf(q, qend-q, nonascii_suffix, enc->name); encidx = rb_ascii8bit_encindex(); } /* result from dump is ASCII */ rb_enc_associate_index(result, encidx); ENC_CODERANGE_SET(result, ENC_CODERANGE_7BIT); return result; }
#each_byte {|integer| ... } ⇒ String
#each_byte ⇒ Enumerator
String
#each_byte ⇒ Enumerator
Passes each byte in str to the given block, or returns an enumerator if no block is given.
"hello".each_byte {|c| print c, ' ' }
produces:
104 101 108 108 111
# File 'string.c', line 8405
static VALUE rb_str_each_byte(VALUE str) { RETURN_SIZED_ENUMERATOR(str, 0, 0, rb_str_each_byte_size); return rb_str_enumerate_bytes(str, 0); }
#each_char {|cstr| ... } ⇒ String
#each_char ⇒ Enumerator
String
#each_char ⇒ Enumerator
Passes each character in str to the given block, or returns an enumerator if no block is given.
"hello".each_char {|c| print c, ' ' }
produces:
h e l l o
# File 'string.c', line 8483
static VALUE rb_str_each_char(VALUE str) { RETURN_SIZED_ENUMERATOR(str, 0, 0, rb_str_each_char_size); return rb_str_enumerate_chars(str, 0); }
#each_codepoint {|integer| ... } ⇒ String
#each_codepoint ⇒ Enumerator
String
#each_codepoint ⇒ Enumerator
Passes the ::Integer
ordinal of each character in str, also known as a codepoint when applied to Unicode strings to the given block. For encodings other than UTF-8/UTF-16(BE|LE)/UTF-32(BE|LE), values are directly derived from the binary representation of each character.
If no block is given, an enumerator is returned instead.
"hello\u0639".each_codepoint {|c| print c, ' ' }
produces:
104 101 108 108 111 1593
# File 'string.c', line 8557
static VALUE rb_str_each_codepoint(VALUE str) { RETURN_SIZED_ENUMERATOR(str, 0, 0, rb_str_each_char_size); return rb_str_enumerate_codepoints(str, 0); }
#each_grapheme_cluster {|cstr| ... } ⇒ String
#each_grapheme_cluster ⇒ Enumerator
String
#each_grapheme_cluster ⇒ Enumerator
Passes each grapheme cluster in str to the given block, or returns an enumerator if no block is given. Unlike #each_char, this enumerates by grapheme clusters defined by Unicode Standard Annex #29 unicode.org/reports/tr29/
"a\u0300".each_char.to_a.size #=> 2
"a\u0300".each_grapheme_cluster.to_a.size #=> 1
# File 'string.c', line 8707
static VALUE rb_str_each_grapheme_cluster(VALUE str) { RETURN_SIZED_ENUMERATOR(str, 0, 0, rb_str_each_grapheme_cluster_size); return rb_str_enumerate_grapheme_clusters(str, 0); }
#each_line(separator = $/, chomp: false) {|substr| ... } ⇒ String
#each_line(separator = $/, chomp: false) ⇒ Enumerator
String
#each_line(separator = $/, chomp: false) ⇒ Enumerator
Splits str using the supplied parameter as the record separator ($/
by default), passing each substring in turn to the supplied block. If a zero-length record separator is supplied, the string is split into paragraphs delimited by multiple successive newlines.
If #chomp is true
, separator
will be removed from the end of each line.
If no block is given, an enumerator is returned instead.
"hello\nworld".each_line {|s| p s}
# prints:
# "hello\n"
# "world"
"hello\nworld".each_line('l') {|s| p s}
# prints:
# "hel"
# "l"
# "o\nworl"
# "d"
"hello\n\n\nworld".each_line('') {|s| p s}
# prints
# "hello\n\n"
# "world"
"hello\nworld".each_line(chomp: true) {|s| p s}
# prints:
# "hello"
# "world"
"hello\nworld".each_line('l', chomp: true) {|s| p s}
# prints:
# "he"
# ""
# "o\nwor"
# "d"
# File 'string.c', line 8337
static VALUE rb_str_each_line(int argc, VALUE *argv, VALUE str) { RETURN_SIZED_ENUMERATOR(str, argc, argv, 0); return rb_str_enumerate_lines(argc, argv, str, 0); }
#encode(encoding [, options] ) ⇒ String
#encode(dst_encoding, src_encoding [, options] ) ⇒ String
#encode([options]) ⇒ String
String
#encode(dst_encoding, src_encoding [, options] ) ⇒ String
#encode([options]) ⇒ String
The first form returns a copy of str
transcoded to encoding #encoding. The second form returns a copy of str
transcoded from src_encoding to dst_encoding. The last form returns a copy of str
transcoded to Encoding.default_internal.
By default, the first and second form raise ::Encoding::UndefinedConversionError
for characters that are undefined in the destination encoding, and ::Encoding::InvalidByteSequenceError
for invalid byte sequences in the source encoding. The last form by default does not raise exceptions but uses replacement strings.
The options
::Hash
gives details for conversion and can have the following keys:
:invalid
-
If the value is
:replace
, #encode replaces invalid byte sequences instr
with the replacement character. The default is to raise the Encoding::InvalidByteSequenceError exception :undef
-
If the value is
:replace
, #encode replaces characters which are undefined in the destination encoding with the replacement character. The default is to raise the Encoding::UndefinedConversionError. :replace
-
Sets the replacement string to the given value. The default replacement string is “uFFFD” for Unicode encoding forms, and “?” otherwise.
:fallback
-
Sets the replacement string by the given object for undefined character. The object should be a Hash, a Proc, a Method, or an object which has [] method. Its key is an undefined character encoded in the source encoding of current transcoder. Its value can be any encoding until it can be converted into the destination encoding of the transcoder.
:xml
-
The value must be
:text
or:attr
. If the value is:text
#encode replaces undefined characters with their (upper-case hexadecimal) numeric character references. ‘&’, ‘<’, and ‘>’ are converted to “&”, “<”, and “>”, respectively. If the value is:attr
, #encode also quotes the replacement result (using ‘“’), and replaces ‘”’ with “"”. :cr_newline
-
Replaces LF (“n”) with CR (“r”) if value is true.
:crlf_newline
-
Replaces LF (“n”) with CRLF (“rn”) if value is true.
:universal_newline
-
Replaces CRLF (“rn”) and CR (“r”) with LF (“n”) if value is true.
# File 'transcode.c', line 2861
static VALUE str_encode(int argc, VALUE *argv, VALUE str) { VALUE newstr = str; int encidx = str_transcode(argc, argv, &newstr); return encoded_dup(newstr, str, encidx); }
#encode!(encoding [, options] ) ⇒ String
#encode!(dst_encoding, src_encoding [, options] ) ⇒ String
String
#encode!(dst_encoding, src_encoding [, options] ) ⇒ String
# File 'transcode.c', line 2783
static VALUE str_encode_bang(int argc, VALUE *argv, VALUE str) { VALUE newstr; int encidx; rb_check_frozen(str); newstr = str; encidx = str_transcode(argc, argv, &newstr); if (encidx < 0) return str; if (newstr == str) { rb_enc_associate_index(str, encidx); return str; } rb_str_shared_replace(str, newstr); return str_encode_associate(str, encidx); }
#encoding ⇒ Encoding
Alias for Regexp#encoding.
#end_with?([suffixes]+) ⇒ Boolean
Returns true if str
ends with one of the suffixes
given.
"hello".end_with?("ello") #=> true
# returns true if one of the suffixes matches.
"hello".end_with?("heaven", "ello") #=> true
"hello".end_with?("heaven", "paradise") #=> false
# File 'string.c', line 9892
static VALUE rb_str_end_with(int argc, VALUE *argv, VALUE str) { int i; char *p, *s, *e; rb_encoding *enc; for (i=0; i<argc; i++) { VALUE tmp = argv[i]; StringValue(tmp); enc = rb_enc_check(str, tmp); if (RSTRING_LEN(str) < RSTRING_LEN(tmp)) continue; p = RSTRING_PTR(str); e = p + RSTRING_LEN(str); s = e - RSTRING_LEN(tmp); if (rb_enc_left_char_head(p, s, e, enc) != s) continue; if (memcmp(s, RSTRING_PTR(tmp), RSTRING_LEN(tmp)) == 0) return Qtrue; } return Qfalse; }
#eql?(other) ⇒ Boolean
Two strings are equal if they have the same length and content.
# File 'string.c', line 3286
MJIT_FUNC_EXPORTED VALUE rb_str_eql(VALUE str1, VALUE str2) { if (str1 == str2) return Qtrue; if (!RB_TYPE_P(str2, T_STRING)) return Qfalse; return rb_str_eql_internal(str1, str2); }
#force_encoding(encoding) ⇒ String
Changes the encoding to #encoding and returns self.
# File 'string.c', line 10108
static VALUE rb_str_force_encoding(VALUE str, VALUE enc) { str_modifiable(str); rb_enc_associate(str, rb_to_encoding(enc)); ENC_CODERANGE_CLEAR(str); return str; }
#freeze
[ GitHub ]# File 'string.c', line 2615
VALUE rb_str_freeze(VALUE str) { if (OBJ_FROZEN(str)) return str; rb_str_resize(str, RSTRING_LEN(str)); return rb_obj_freeze(str); }
#getbyte(index) ⇒ 0
.. 255
returns the indexth byte as an integer.
# File 'string.c', line 5419
static VALUE rb_str_getbyte(VALUE str, VALUE index) { long pos = NUM2LONG(index); if (pos < 0) pos += RSTRING_LEN(str); if (pos < 0 || RSTRING_LEN(str) <= pos) return Qnil; return INT2FIX((unsigned char)RSTRING_PTR(str)[pos]); }
#grapheme_clusters ⇒ Array
Returns an array of grapheme clusters in str. This is a shorthand for str.each_grapheme_cluster.to_a
.
If a block is given, which is a deprecated form, works the same as #each_grapheme_cluster.
# File 'string.c', line 8725
static VALUE rb_str_grapheme_clusters(VALUE str) { VALUE ary = WANTARRAY("grapheme_clusters", rb_str_strlen(str)); return rb_str_enumerate_grapheme_clusters(str, ary); }
#gsub(pattern, replacement) ⇒ String
#gsub(pattern, hash) ⇒ String
#gsub(pattern) {|match| ... } ⇒ String
#gsub(pattern) ⇒ Enumerator
String
#gsub(pattern, hash) ⇒ String
#gsub(pattern) {|match| ... } ⇒ String
#gsub(pattern) ⇒ Enumerator
Returns a copy of str with all occurrences of pattern substituted for the second argument. The pattern is typically a Regexp; if given as a String
, any regular expression metacharacters it contains will be interpreted literally, e.g. \d
will match a backslash followed by ‘d’, instead of a digit.
If replacement
is a String
it will be substituted for the matched text. It may contain back-references to the pattern’s capture groups of the form \d
, where d is a group number, or \k<n>
, where n is a group name. Similarly, \&
, \'
, \`
, and +
correspond to special variables, $&
, $'
, $`
, and $+
, respectively. (See regexp.rdoc for details.) \0
is the same as \&
. \\
is interpreted as an escape, i.e., a single backslash. Note that, within replacement
the special match variables, such as $&
, will not refer to the current match.
If the second argument is a ::Hash
, and the matched text is one of its keys, the corresponding value is the replacement string.
In the block form, the current match string is passed in as a parameter, and variables such as $1
, $2
, $`
, $&
, and $'
will be set appropriately. (See regexp.rdoc for details.) The value returned by the block will be substituted for the match on each call.
When neither a block nor a second argument is supplied, an ::Enumerator
is returned.
"hello".gsub(/[aeiou]/, '*') #=> "h*ll*"
"hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"
"hello".gsub(/./) {|s| s.ord.to_s + ' '} #=> "104 101 108 108 111 "
"hello".gsub(/(?<foo>[aeiou])/, '{\k<foo>}') #=> "h{e}ll{o}"
'hello'.gsub(/[eo]/, 'e' => 3, 'o' => '*') #=> "h3ll*"
Note that a string literal consumes backslashes. (See syntax/literals.rdoc for details on string literals.) Back-references are typically preceded by an additional backslash. For example, if you want to write a back-reference \&
in replacement
with a double-quoted string literal, you need to write: "..\\&.."
. If you want to write a non-back-reference string \&
in replacement
, you need first to escape the backslash to prevent this method from interpreting it as a back-reference, and then you need to escape the backslashes again to prevent a string literal from consuming them: "..\\\\&.."
. You may want to use the block form to avoid a lot of backslashes.
# File 'string.c', line 5344
static VALUE rb_str_gsub(int argc, VALUE *argv, VALUE str) { return str_gsub(argc, argv, str, 0); }
#gsub!(pattern, replacement) ⇒ String
?
#gsub!(pattern, hash) ⇒ String
?
#gsub!(pattern) {|match| ... } ⇒ String
?
#gsub!(pattern) ⇒ Enumerator
String
?
#gsub!(pattern, hash) ⇒ String
?
#gsub!(pattern) {|match| ... } ⇒ String
?
#gsub!(pattern) ⇒ Enumerator
Performs the substitutions of #gsub in place, returning str, or nil
if no substitutions were performed. If no block and no replacement is given, an enumerator is returned instead.
# File 'string.c', line 5276
static VALUE rb_str_gsub_bang(int argc, VALUE *argv, VALUE str) { str_modify_keep_cr(str); return str_gsub(argc, argv, str, 1); }
#hash ⇒ Integer
Returns a hash based on the string’s length, content and encoding.
See also Object#hash.
# File 'string.c', line 3193
static VALUE rb_str_hash_m(VALUE str) { st_index_t hval = rb_str_hash(str); return ST2FIX(hval); }
#hex ⇒ Integer
Treats leading characters from str as a string of hexadecimal digits (with an optional sign and an optional 0x
) and returns the corresponding number. Zero is returned on error.
"0x0a".hex #=> 10
"-1234".hex #=> -4660
"0".hex #=> 0
"wombat".hex #=> 0
# File 'string.c', line 9369
static VALUE rb_str_hex(VALUE str) { return rb_str_to_inum(str, 16, FALSE); }
#include?(other_str) ⇒ Boolean
Returns true
if str contains the given string or character.
"hello".include? "lo" #=> true
"hello".include? "ol" #=> false
"hello".include? ?h #=> true
# File 'string.c', line 5714
static VALUE rb_str_include(VALUE str, VALUE arg) { long i; StringValue(arg); i = rb_str_index(str, arg, 0); if (i == -1) return Qfalse; return Qtrue; }
Returns the index of the first occurrence of the given substring or pattern (regexp) in str. Returns nil
if not found. If the second parameter is present, it specifies the position in the string to begin the search.
"hello".index('e') #=> 1
"hello".index('lo') #=> 3
"hello".index('a') #=> nil
"hello".index(?e) #=> 1
"hello".index(/[aeiou]/, -3) #=> 4
# File 'string.c', line 3547
static VALUE rb_str_index_m(int argc, VALUE *argv, VALUE str) { VALUE sub; VALUE initpos; long pos; if (rb_scan_args(argc, argv, "11", &sub, &initpos) == 2) { pos = NUM2LONG(initpos); } else { pos = 0; } if (pos < 0) { pos += str_strlen(str, NULL); if (pos < 0) { if (RB_TYPE_P(sub, T_REGEXP)) { rb_backref_set(Qnil); } return Qnil; } } if (SPECIAL_CONST_P(sub)) goto generic; switch (BUILTIN_TYPE(sub)) { case T_REGEXP: if (pos > str_strlen(str, NULL)) return Qnil; pos = str_offset(RSTRING_PTR(str), RSTRING_END(str), pos, rb_enc_check(str, sub), single_byte_optimizable(str)); pos = rb_reg_search(sub, str, pos, 0); pos = rb_str_sublen(str, pos); break; generic: default: { VALUE tmp; tmp = rb_check_string_type(sub); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sub)); } sub = tmp; } /* fall through */ case T_STRING: pos = rb_str_index(str, sub, pos); pos = rb_str_sublen(str, pos); break; } if (pos == -1) return Qnil; return LONG2NUM(pos); }
#replace(other_str) ⇒ String
#initialize_copy(other_str) ⇒ String
String
#initialize_copy(other_str) ⇒ String
Alias for #replace.
#insert(index, other_str) ⇒ String
Inserts other_str before the character at the given index, modifying str. Negative indices count from the end of the string, and insert after the given character. The intent is insert aString so that it starts at the given index.
"abcd".insert(0, 'X') #=> "Xabcd"
"abcd".insert(3, 'X') #=> "abcXd"
"abcd".insert(4, 'X') #=> "abcdX"
"abcd".insert(-3, 'X') #=> "abXcd"
"abcd".insert(-1, 'X') #=> "abcdX"
# File 'string.c', line 4826
static VALUE rb_str_insert(VALUE str, VALUE idx, VALUE str2) { long pos = NUM2LONG(idx); if (pos == -1) { return rb_str_append(str, str2); } else if (pos < 0) { pos++; } rb_str_splice(str, pos, 0, str2); return str; }
#inspect ⇒ String
Returns a printable version of str, surrounded by quote marks, with special characters escaped.
str = "hello"
str[3] = "\b"
str.inspect #=> "\"hel\\bo\""
# File 'string.c', line 5929
VALUE rb_str_inspect(VALUE str) { int encidx = ENCODING_GET(str); rb_encoding *enc = rb_enc_from_index(encidx), *actenc; const char *p, *pend, *prev; char buf[CHAR_ESC_LEN + 1]; VALUE result = rb_str_buf_new(0); rb_encoding *resenc = rb_default_internal_encoding(); int unicode_p = rb_enc_unicode_p(enc); int asciicompat = rb_enc_asciicompat(enc); if (resenc == NULL) resenc = rb_default_external_encoding(); if (!rb_enc_asciicompat(resenc)) resenc = rb_usascii_encoding(); rb_enc_associate(result, resenc); str_buf_cat2(result, "\""); p = RSTRING_PTR(str); pend = RSTRING_END(str); prev = p; actenc = get_actual_encoding(encidx, str); if (actenc != enc) { enc = actenc; if (unicode_p) unicode_p = rb_enc_unicode_p(enc); } while (p < pend) { unsigned int c, cc; int n; n = rb_enc_precise_mbclen(p, pend, enc); if (!MBCLEN_CHARFOUND_P(n)) { if (p > prev) str_buf_cat(result, prev, p - prev); n = rb_enc_mbminlen(enc); if (pend < p + n) n = (int)(pend - p); while (n--) { snprintf(buf, CHAR_ESC_LEN, "\\x%02X", *p & 0377); str_buf_cat(result, buf, strlen(buf)); prev = ++p; } continue; } n = MBCLEN_CHARFOUND_LEN(n); c = rb_enc_mbc_to_codepoint(p, pend, enc); p += n; if ((asciicompat || unicode_p) && (c == '"'|| c == '\\' || (c == '#' && p < pend && MBCLEN_CHARFOUND_P(rb_enc_precise_mbclen(p,pend,enc)) && (cc = rb_enc_codepoint(p,pend,enc), (cc == '$' || cc == '@' || cc == '{'))))) { if (p - n > prev) str_buf_cat(result, prev, p - n - prev); str_buf_cat2(result, "\\"); if (asciicompat || enc == resenc) { prev = p - n; continue; } } switch (c) { case '\n': cc = 'n'; break; case '\r': cc = 'r'; break; case '\t': cc = 't'; break; case '\f': cc = 'f'; break; case '\013': cc = 'v'; break; case '\010': cc = 'b'; break; case '\007': cc = 'a'; break; case 033: cc = 'e'; break; default: cc = 0; break; } if (cc) { if (p - n > prev) str_buf_cat(result, prev, p - n - prev); buf[0] = '\\'; buf[1] = (char)cc; str_buf_cat(result, buf, 2); prev = p; continue; } if ((enc == resenc && rb_enc_isprint(c, enc)) || (asciicompat && rb_enc_isascii(c, enc) && ISPRINT(c))) { continue; } else { if (p - n > prev) str_buf_cat(result, prev, p - n - prev); rb_str_buf_cat_escaped_char(result, c, unicode_p); prev = p; continue; } } if (p > prev) str_buf_cat(result, prev, p - prev); str_buf_cat2(result, "\""); return result; }
Also known as: #to_sym
Returns the ::Symbol
corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.
"Koala".intern #=> :Koala
s = 'cat'.to_sym #=> :cat
s == :cat #=> true
s = '@cat'.to_sym #=> :@cat
s == :@cat #=> true
This can also be used to create symbols that cannot be represented using the :xxx
notation.
'cat and dog'.to_sym #=> :"cat and dog"
# File 'symbol.c', line 709
VALUE rb_str_intern(VALUE str) { #if USE_SYMBOL_GC rb_encoding *enc, *ascii; int type; #else ID id; #endif VALUE sym = lookup_str_sym(str); if (sym) { return sym; } #if USE_SYMBOL_GC enc = rb_enc_get(str); ascii = rb_usascii_encoding(); if (enc != ascii && sym_check_asciionly(str)) { str = rb_str_dup(str); rb_enc_associate(str, ascii); OBJ_FREEZE(str); enc = ascii; } else { str = rb_str_dup(str); OBJ_FREEZE(str); } str = rb_fstring(str); type = rb_str_symname_type(str, IDSET_ATTRSET_FOR_INTERN); if (type < 0) type = ID_JUNK; return dsymbol_alloc(rb_cSymbol, str, enc, type); #else id = intern_str(str, 0); return ID2SYM(id); #endif }
Also known as: #size
Returns the character length of str.
# File 'string.c', line 1842
VALUE rb_str_length(VALUE str) { return LONG2NUM(str_strlen(str, NULL)); }
#lines(separator = $/, chomp: false) ⇒ Array
Returns an array of lines in str split using the supplied record separator ($/
by default). This is a shorthand for str.each_line(separator, getline_args).to_a
.
If #chomp is true
, separator
will be removed from the end of each line.
"hello\nworld\n".lines #=> ["hello\n", "world\n"]
"hello world".lines(' ') #=> ["hello ", " ", "world"]
"hello\nworld\n".lines(chomp: true) #=> ["hello", "world"]
If a block is given, which is a deprecated form, works the same as #each_line.
# File 'string.c', line 8363
static VALUE rb_str_lines(int argc, VALUE *argv, VALUE str) { VALUE ary = WANTARRAY("lines", 0); return rb_str_enumerate_lines(argc, argv, str, ary); }
#ljust(integer, padstr = ' ') ⇒ String
If integer is greater than the length of str, returns a new String
of length integer with str left justified and padded with padstr; otherwise, returns str.
"hello".ljust(4) #=> "hello"
"hello".ljust(20) #=> "hello "
"hello".ljust(20, '1234') #=> "hello123412341234123"
# File 'string.c', line 9704
static VALUE rb_str_ljust(int argc, VALUE *argv, VALUE str) { return rb_str_justify(argc, argv, str, 'l'); }
#lstrip ⇒ String
# File 'string.c', line 9062
static VALUE rb_str_lstrip(VALUE str) { char *start; long len, loffset; RSTRING_GETMEM(str, start, len); loffset = lstrip_offset(str, start, start+len, STR_ENC_GET(str)); if (loffset <= 0) return rb_str_dup(str); return rb_str_subseq(str, loffset, len - loffset); }
#lstrip! ⇒ self
?
# File 'string.c', line 9024
static VALUE rb_str_lstrip_bang(VALUE str) { rb_encoding *enc; char *start, *s; long olen, loffset; str_modify_keep_cr(str); enc = STR_ENC_GET(str); RSTRING_GETMEM(str, start, olen); loffset = lstrip_offset(str, start, start+olen, enc); if (loffset > 0) { long len = olen-loffset; s = start + loffset; memmove(start, s, len); STR_SET_LEN(str, len); #if !SHARABLE_MIDDLE_SUBSTRING TERM_FILL(start+len, rb_enc_mbminlen(enc)); #endif return str; } return Qnil; }
Converts pattern to a ::Regexp
(if it isn’t already one), then invokes its match
method on str. If the second parameter is present, it specifies the position in the string to begin the search.
'hello'.match('(.)\1') #=> #<MatchData "ll" 1:"l">
'hello'.match('(.)\1')[0] #=> "ll"
'hello'.match(/(.)\1/)[0] #=> "ll"
'hello'.match(/(.)\1/, 3) #=> nil
'hello'.match('xx') #=> nil
If a block is given, invoke the block with ::MatchData
if match succeed, so that you can write
str.match(pat) {|m| ...}
instead of
if m = str.match(pat)
#...
end
The return value is a value from block execution in this case.
# File 'string.c', line 3838
static VALUE rb_str_match_m(int argc, VALUE *argv, VALUE str) { VALUE re, result; if (argc < 1) rb_check_arity(argc, 1, 2); re = argv[0]; argv[0] = str; result = rb_funcallv(get_pat(re), rb_intern("match"), argc, argv); if (!NIL_P(result) && rb_block_given_p()) { return rb_yield(result); } return result; }
#match?(pattern) ⇒ Boolean
#match?(pattern, pos) ⇒ Boolean
Boolean
#match?(pattern, pos) ⇒ Boolean
Converts pattern to a ::Regexp
(if it isn’t already one), then returns a true
or false
indicates whether the regexp is matched str or not without updating $~
and other related variables. If the second parameter is present, it specifies the position in the string to begin the search.
"Ruby".match?(/R.../) #=> true
"Ruby".match?(/R.../, 1) #=> false
"Ruby".match?(/P.../) #=> false
$& #=> nil
# File 'string.c', line 3870
static VALUE rb_str_match_m_p(int argc, VALUE *argv, VALUE str) { VALUE re; rb_check_arity(argc, 1, 2); re = get_pat(argv[0]); return rb_reg_match_p(re, str, argc > 1 ? NUM2LONG(argv[1]) : 0); }
#succ ⇒ String
#next ⇒ String
Also known as: #succ
String
#next ⇒ String
Returns the successor to str. The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case. Incrementing nonalphanumerics uses the underlying character set’s collating sequence.
If the increment generates a “carry,” the character to the left of it is incremented. This process repeats until there is no carry, adding an additional character if necessary.
"abcd".succ #=> "abce"
"THX1138".succ #=> "THX1139"
"<<koala>>".succ #=> "<<koalb>>"
"1999zzz".succ #=> "2000aaa"
"ZZZ9999".succ #=> "AAAA0000"
"***".succ #=> "**+"
# File 'string.c', line 4089
VALUE rb_str_succ(VALUE orig) { VALUE str; str = rb_str_new_with_class(orig, RSTRING_PTR(orig), RSTRING_LEN(orig)); rb_enc_cr_str_copy_for_substr(str, orig); return str_succ(str); }
#succ! ⇒ String
#next! ⇒ String
Also known as: #succ!
String
#next! ⇒ String
Equivalent to #succ, but modifies the receiver in place.
# File 'string.c', line 4194
static VALUE rb_str_succ_bang(VALUE str) { rb_str_modify(str); str_succ(str); return str; }
#oct ⇒ Integer
Treats leading characters of str as a string of octal digits (with an optional sign) and returns the corresponding number. Returns 0 if the conversion fails.
"123".oct #=> 83
"-377".oct #=> -255
"bad".oct #=> 0
"0377bad".oct #=> 255
If str
starts with 0
, radix indicators are honored. See Kernel.Integer.
# File 'string.c', line 9393
static VALUE rb_str_oct(VALUE str) { return rb_str_to_inum(str, -8, FALSE); }
#ord ⇒ Integer
Returns the ::Integer
ordinal of a one-character string.
"a".ord #=> 97
# File 'string.c', line 9526
VALUE rb_str_ord(VALUE s) { unsigned int c; c = rb_enc_codepoint(RSTRING_PTR(s), RSTRING_END(s), STR_ENC_GET(s)); return UINT2NUM(c); }
Searches sep or pattern (regexp) in the string and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".partition("l") #=> ["he", "l", "lo"]
"hello".partition("x") #=> ["hello", "", ""]
"hello".partition(/.l/) #=> ["h", "el", "lo"]
# File 'string.c', line 9765
static VALUE rb_str_partition(VALUE str, VALUE sep) { long pos; sep = get_pat_quoted(sep, 0); if (RB_TYPE_P(sep, T_REGEXP)) { pos = rb_reg_search(sep, str, 0, 0); if (pos < 0) { failed: return rb_ary_new3(3, rb_str_dup(str), str_new_empty(str), str_new_empty(str)); } sep = rb_str_subpat(str, sep, INT2FIX(0)); if (pos == 0 && RSTRING_LEN(sep) == 0) goto failed; } else { pos = rb_str_index(str, sep, 0); if (pos < 0) goto failed; } return rb_ary_new3(3, rb_str_subseq(str, 0, pos), sep, rb_str_subseq(str, pos+RSTRING_LEN(sep), RSTRING_LEN(str)-pos-RSTRING_LEN(sep))); }
#prepend(other_str1, other_str2, ...) ⇒ String
Prepend—Prepend the given strings to str.
a = "!"
a.prepend("hello ", "world") #=> "hello world!"
a #=> "hello world!"
See also #concat.
# File 'string.c', line 3141
static VALUE rb_str_prepend_multi(int argc, VALUE *argv, VALUE str) { str_modifiable(str); if (argc == 1) { rb_str_update(str, 0L, 0L, argv[0]); } else if (argc > 1) { int i; VALUE arg_str = rb_str_tmp_new(0); rb_enc_copy(arg_str, str); for (i = 0; i < argc; i++) { rb_str_append(arg_str, argv[i]); } rb_str_update(str, 0L, 0L, arg_str); } return str; }
#replace(other_str) ⇒ String
Also known as: #initialize_copy
Replaces the contents of str with the corresponding values in other_str.
s = "hello" #=> "hello"
s.replace "world" #=> "world"
# File 'string.c', line 5362
VALUE rb_str_replace(VALUE str, VALUE str2) { str_modifiable(str); if (str == str2) return str; StringValue(str2); str_discard(str); return str_replace(str, str2); }
#reverse ⇒ String
Returns a new string with the characters from str in reverse order.
"stressed".reverse #=> "desserts"
# File 'string.c', line 5617
static VALUE rb_str_reverse(VALUE str) { rb_encoding *enc; VALUE rev; char *s, *e, *p; int cr; if (RSTRING_LEN(str) <= 1) return rb_str_dup(str); enc = STR_ENC_GET(str); rev = rb_str_new_with_class(str, 0, RSTRING_LEN(str)); s = RSTRING_PTR(str); e = RSTRING_END(str); p = RSTRING_END(rev); cr = ENC_CODERANGE(str); if (RSTRING_LEN(str) > 1) { if (single_byte_optimizable(str)) { while (s < e) { *--p = *s++; } } else if (cr == ENC_CODERANGE_VALID) { while (s < e) { int clen = rb_enc_fast_mbclen(s, e, enc); p -= clen; memcpy(p, s, clen); s += clen; } } else { cr = rb_enc_asciicompat(enc) ? ENC_CODERANGE_7BIT : ENC_CODERANGE_VALID; while (s < e) { int clen = rb_enc_mbclen(s, e, enc); if (clen > 1 || (*s & 0x80)) cr = ENC_CODERANGE_UNKNOWN; p -= clen; memcpy(p, s, clen); s += clen; } } } STR_SET_LEN(rev, RSTRING_LEN(str)); str_enc_copy(rev, str); ENC_CODERANGE_SET(rev, cr); return rev; }
#reverse! ⇒ String
Reverses str in place.
# File 'string.c', line 5675
static VALUE rb_str_reverse_bang(VALUE str) { if (RSTRING_LEN(str) > 1) { if (single_byte_optimizable(str)) { char *s, *e, c; str_modify_keep_cr(str); s = RSTRING_PTR(str); e = RSTRING_END(str) - 1; while (s < e) { c = *s; *s++ = *e; *e-- = c; } } else { str_shared_replace(str, rb_str_reverse(str)); } } else { str_modify_keep_cr(str); } return str; }
Returns the index of the last occurrence of the given substring or pattern (regexp) in str. Returns nil
if not found. If the second parameter is present, it specifies the position in the string to end the search—characters beyond this point will not be considered.
"hello".rindex('e') #=> 1
"hello".rindex('l') #=> 3
"hello".rindex('a') #=> nil
"hello".rindex(?e) #=> 1
"hello".rindex(/[aeiou]/, -2) #=> 1
# File 'string.c', line 3712
static VALUE rb_str_rindex_m(int argc, VALUE *argv, VALUE str) { VALUE sub; VALUE vpos; rb_encoding *enc = STR_ENC_GET(str); long pos, len = str_strlen(str, enc); /* str's enc */ if (rb_scan_args(argc, argv, "11", &sub, &vpos) == 2) { pos = NUM2LONG(vpos); if (pos < 0) { pos += len; if (pos < 0) { if (RB_TYPE_P(sub, T_REGEXP)) { rb_backref_set(Qnil); } return Qnil; } } if (pos > len) pos = len; } else { pos = len; } if (SPECIAL_CONST_P(sub)) goto generic; switch (BUILTIN_TYPE(sub)) { case T_REGEXP: /* enc = rb_get_check(str, sub); */ pos = str_offset(RSTRING_PTR(str), RSTRING_END(str), pos, enc, single_byte_optimizable(str)); pos = rb_reg_search(sub, str, pos, 1); pos = rb_str_sublen(str, pos); if (pos >= 0) return LONG2NUM(pos); break; generic: default: { VALUE tmp; tmp = rb_check_string_type(sub); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sub)); } sub = tmp; } /* fall through */ case T_STRING: pos = rb_str_rindex(str, sub, pos); if (pos >= 0) return LONG2NUM(pos); break; } return Qnil; }
#rjust(integer, padstr = ' ') ⇒ String
If integer is greater than the length of str, returns a new String
of length integer with str right justified and padded with padstr; otherwise, returns str.
"hello".rjust(4) #=> "hello"
"hello".rjust(20) #=> " hello"
"hello".rjust(20, '1234') #=> "123412341234123hello"
# File 'string.c', line 9724
static VALUE rb_str_rjust(int argc, VALUE *argv, VALUE str) { return rb_str_justify(argc, argv, str, 'r'); }
Searches sep or pattern (regexp) in the string from the end of the string, and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".rpartition("l") #=> ["hel", "l", "o"]
"hello".rpartition("x") #=> ["", "", "hello"]
"hello".rpartition(/.l/) #=> ["he", "ll", "o"]
# File 'string.c', line 9805
static VALUE rb_str_rpartition(VALUE str, VALUE sep) { long pos = RSTRING_LEN(str); int regex = FALSE; if (RB_TYPE_P(sep, T_REGEXP)) { pos = rb_reg_search(sep, str, pos, 1); regex = TRUE; } else { VALUE tmp; tmp = rb_check_string_type(sep); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sep)); } sep = tmp; pos = rb_str_sublen(str, pos); pos = rb_str_rindex(str, sep, pos); } if (pos < 0) { return rb_ary_new3(3, str_new_empty(str), str_new_empty(str), rb_str_dup(str)); } if (regex) { sep = rb_reg_nth_match(0, rb_backref_get()); } else { pos = rb_str_offset(str, pos); } return rb_ary_new3(3, rb_str_subseq(str, 0, pos), sep, rb_str_subseq(str, pos+RSTRING_LEN(sep), RSTRING_LEN(str)-pos-RSTRING_LEN(sep))); }
#rstrip ⇒ String
# File 'string.c', line 9151
static VALUE rb_str_rstrip(VALUE str) { rb_encoding *enc; char *start; long olen, roffset; enc = STR_ENC_GET(str); RSTRING_GETMEM(str, start, olen); roffset = rstrip_offset(str, start, start+olen, enc); if (roffset <= 0) return rb_str_dup(str); return rb_str_subseq(str, 0, olen-roffset); }
#rstrip! ⇒ self
?
# File 'string.c', line 9114
static VALUE rb_str_rstrip_bang(VALUE str) { rb_encoding *enc; char *start; long olen, roffset; str_modify_keep_cr(str); enc = STR_ENC_GET(str); RSTRING_GETMEM(str, start, olen); roffset = rstrip_offset(str, start, start+olen, enc); if (roffset > 0) { long len = olen - roffset; STR_SET_LEN(str, len); #if !SHARABLE_MIDDLE_SUBSTRING TERM_FILL(start+len, rb_enc_mbminlen(enc)); #endif return str; } return Qnil; }
#scan(pattern) ⇒ Array
#scan(pattern) {|match, ...| ... } ⇒ String
String
Both forms iterate through str, matching the pattern (which may be a ::Regexp
or a String
). For each match, a result is generated and either added to the result array or passed to the block. If the pattern contains no groups, each individual result consists of the matched string, $&
. If the pattern contains groups, each individual result is itself an array containing one entry per group.
a = "cruel world"
a.scan(/\w+/) #=> ["cruel", "world"]
a.scan(/.../) #=> ["cru", "el ", "wor"]
a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]]
a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]
And the block form:
a.scan(/\w+/) {|w| print "<<#{w}>> " }
print "\n"
a.scan(/(.)(.)/) {|x,y| print y, x }
print "\n"
produces:
<<cruel>> <<world>>
rceu lowlr
# File 'string.c', line 9321
static VALUE rb_str_scan(VALUE str, VALUE pat) { VALUE result; long start = 0; long last = -1, prev = 0; char *p = RSTRING_PTR(str); long len = RSTRING_LEN(str); pat = get_pat_quoted(pat, 1); mustnot_broken(str); if (!rb_block_given_p()) { VALUE ary = rb_ary_new(); while (!NIL_P(result = scan_once(str, pat, &start, 0))) { last = prev; prev = start; rb_ary_push(ary, result); } if (last >= 0) rb_pat_search(pat, str, last, 1); else rb_backref_set(Qnil); return ary; } while (!NIL_P(result = scan_once(str, pat, &start, 1))) { last = prev; prev = start; rb_yield(result); str_mod_check(str, p, len); } if (last >= 0) rb_pat_search(pat, str, last, 1); return str; }
#scrub ⇒ String
#scrub(repl) ⇒ String
#scrub {|bytes| ... } ⇒ String
String
#scrub(repl) ⇒ String
#scrub {|bytes| ... } ⇒ String
If the string is invalid byte sequence then replace invalid bytes with given replacement character, else returns self. If block is given, replace invalid bytes with returned value of the block.
"abc\u3042\x81".scrub #=> "abc\u3042\uFFFD"
"abc\u3042\x81".scrub("*") #=> "abc\u3042*"
"abc\u3042\xE3\x80".scrub{|bytes| '<'bytes.unpack('H*')[0]'>' } #=> "abc\u3042<e380>"
# File 'string.c', line 10522
static VALUE str_scrub(int argc, VALUE *argv, VALUE str) { VALUE repl = argc ? (rb_check_arity(argc, 0, 1), argv[0]) : Qnil; VALUE new = rb_str_scrub(str, repl); return NIL_P(new) ? rb_str_dup(str): new; }
#scrub! ⇒ String
#scrub!(repl) ⇒ String
#scrub! {|bytes| ... } ⇒ String
String
#scrub!(repl) ⇒ String
#scrub! {|bytes| ... } ⇒ String
If the string is invalid byte sequence then replace invalid bytes with given replacement character, else returns self. If block is given, replace invalid bytes with returned value of the block.
"abc\u3042\x81".scrub! #=> "abc\u3042\uFFFD"
"abc\u3042\x81".scrub!("*") #=> "abc\u3042*"
"abc\u3042\xE3\x80".scrub!{|bytes| '<'bytes.unpack('H*')[0]'>' } #=> "abc\u3042<e380>"
# File 'string.c', line 10544
static VALUE str_scrub_bang(int argc, VALUE *argv, VALUE str) { VALUE repl = argc ? (rb_check_arity(argc, 0, 1), argv[0]) : Qnil; VALUE new = rb_str_scrub(str, repl); if (!NIL_P(new)) rb_str_replace(str, new); return str; }
#setbyte(index, integer) ⇒ Integer
modifies the indexth byte as integer.
# File 'string.c', line 5438
static VALUE rb_str_setbyte(VALUE str, VALUE index, VALUE value) { long pos = NUM2LONG(index); long len = RSTRING_LEN(str); char *head, *left = 0; unsigned char *ptr; rb_encoding *enc; int cr = ENC_CODERANGE_UNKNOWN, width, nlen; if (pos < -len || len <= pos) rb_raise(rb_eIndexError, "index %ld out of string", pos); if (pos < 0) pos += len; VALUE v = rb_to_int(value); VALUE w = rb_int_and(v, INT2FIX(0xff)); unsigned char byte = NUM2INT(w) & 0xFF; if (!str_independent(str)) str_make_independent(str); enc = STR_ENC_GET(str); head = RSTRING_PTR(str); ptr = (unsigned char *)&head[pos]; if (!STR_EMBED_P(str)) { cr = ENC_CODERANGE(str); switch (cr) { case ENC_CODERANGE_7BIT: left = (char *)ptr; *ptr = byte; if (ISASCII(byte)) goto end; nlen = rb_enc_precise_mbclen(left, head+len, enc); if (!MBCLEN_CHARFOUND_P(nlen)) ENC_CODERANGE_SET(str, ENC_CODERANGE_BROKEN); else ENC_CODERANGE_SET(str, ENC_CODERANGE_VALID); goto end; case ENC_CODERANGE_VALID: left = rb_enc_left_char_head(head, ptr, head+len, enc); width = rb_enc_precise_mbclen(left, head+len, enc); *ptr = byte; nlen = rb_enc_precise_mbclen(left, head+len, enc); if (!MBCLEN_CHARFOUND_P(nlen)) ENC_CODERANGE_SET(str, ENC_CODERANGE_BROKEN); else if (MBCLEN_CHARFOUND_LEN(nlen) != width || ISASCII(byte)) ENC_CODERANGE_CLEAR(str); goto end; } } ENC_CODERANGE_CLEAR(str); *ptr = byte; end: return value; }
Alias for #length.
#[](index) ⇒ String
?
#[](start, length) ⇒ String
?
#[](range) ⇒ String
?
#[](regexp) ⇒ String
?
#[](regexp, capture) ⇒ String
?
#[](match_str) ⇒ String
?
#slice(index) ⇒ String
?
#slice(start, length) ⇒ String
?
#slice(range) ⇒ String
?
#slice(regexp) ⇒ String
?
#slice(regexp, capture) ⇒ String
?
#slice(match_str) ⇒ String
?
String
?
#[](start, length) ⇒ String
?
#[](range) ⇒ String
?
#[](regexp) ⇒ String
?
#[](regexp, capture) ⇒ String
?
#[](match_str) ⇒ String
?
#slice(index) ⇒ String
?
#slice(start, length) ⇒ String
?
#slice(range) ⇒ String
?
#slice(regexp) ⇒ String
?
#slice(regexp, capture) ⇒ String
?
#slice(match_str) ⇒ String
?
Alias for #[].
#slice!(integer) ⇒ String
?
#slice!(integer, integer) ⇒ String
?
#slice!(range) ⇒ String
?
#slice!(regexp) ⇒ String
?
#slice!(other_str) ⇒ String
?
String
?
#slice!(integer, integer) ⇒ String
?
#slice!(range) ⇒ String
?
#slice!(regexp) ⇒ String
?
#slice!(other_str) ⇒ String
?
Deletes the specified portion from str, and returns the portion deleted.
string = "this is a string"
string.slice!(2) #=> "i"
string.slice!(3..6) #=> " is "
string.slice!(/s.*t/) #=> "sa st"
string.slice!("r") #=> "r"
string #=> "thing"
# File 'string.c', line 4861
static VALUE rb_str_slice_bang(int argc, VALUE *argv, VALUE str) { VALUE result; VALUE buf[3]; int i; rb_check_arity(argc, 1, 2); for (i=0; i<argc; i++) { buf[i] = argv[i]; } str_modify_keep_cr(str); result = rb_str_aref_m(argc, buf, str); if (!NIL_P(result)) { buf[i] = rb_str_new(0,0); rb_str_aset_m(argc+1, buf, str); } return result; }
#split(pattern = nil, [limit]) ⇒ Array
#split(pattern = nil, [limit]) {|sub| ... } ⇒ String
String
Divides str into substrings based on a delimiter, returning an array of these substrings.
If pattern is a String
, then its contents are used as the delimiter when splitting str. If pattern is a single space, str is split on whitespace, with leading and trailing whitespace and runs of contiguous whitespace characters ignored.
If pattern is a ::Regexp
, str is divided where the pattern matches. Whenever the pattern matches a zero-length string, str is split into individual characters. If pattern contains groups, the respective matches will be returned in the array as well.
If pattern is nil
, the value of $;
is used. If $;
is nil
(which is the default), str is split on whitespace as if ‘ ’ were specified.
If the limit parameter is omitted, trailing null fields are suppressed. If limit is a positive number, at most that number of split substrings will be returned (captured groups will be returned as well, but are not counted towards the limit). If limit is 1
, the entire string is returned as the only entry in an array. If negative, there is no limit to the number of fields returned, and trailing null fields are not suppressed.
When the input str
is empty an empty ::Array
is returned as the string is considered to have no fields to split.
" now's the time ".split #=> ["now's", "the", "time"]
" now's the time ".split(' ') #=> ["now's", "the", "time"]
" now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]
"1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]
"hello".split(//) #=> ["h", "e", "l", "l", "o"]
"hello".split(//, 3) #=> ["h", "e", "llo"]
"hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]
"mellow yellow".split("ello") #=> ["m", "w y", "w"]
"1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]
"1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]
"1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]
"1:2:3".split(/(:)()()/, 2) #=> ["1", ":", "", "", "2:3"]
"".split(',', -1) #=> []
If a block is given, invoke the block with each split substring.
# File 'string.c', line 7894
static VALUE rb_str_split_m(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; VALUE spat; VALUE limit; enum {awk, string, regexp, chars} split_type; long beg, end, i = 0, empty_count = -1; int lim = 0; VALUE result, tmp; result = rb_block_given_p() ? Qfalse : Qnil; if (rb_scan_args(argc, argv, "02", &spat, &limit) == 2) { lim = NUM2INT(limit); if (lim <= 0) limit = Qnil; else if (lim == 1) { if (RSTRING_LEN(str) == 0) return result ? rb_ary_new2(0) : str; tmp = rb_str_dup(str); if (!result) { rb_yield(tmp); return str; } return rb_ary_new3(1, tmp); } i = 1; } if (NIL_P(limit) && !lim) empty_count = 0; enc = STR_ENC_GET(str); split_type = regexp; if (!NIL_P(spat)) { spat = get_pat_quoted(spat, 0); } else if (NIL_P(spat = rb_fs)) { split_type = awk; } else if (!(spat = rb_fs_check(spat))) { rb_raise(rb_eTypeError, "value of $; must be String or Regexp"); } else { rb_warn("$; is set to non-nil value"); } if (split_type != awk) { if (BUILTIN_TYPE(spat) == T_STRING) { rb_encoding *enc2 = STR_ENC_GET(spat); mustnot_broken(spat); split_type = string; if (RSTRING_LEN(spat) == 0) { /* Special case - split into chars */ split_type = chars; } else if (rb_enc_asciicompat(enc2) == 1) { if (RSTRING_LEN(spat) == 1 && RSTRING_PTR(spat)[0] == ' ') { split_type = awk; } } else { int l; if (rb_enc_ascget(RSTRING_PTR(spat), RSTRING_END(spat), &l, enc2) == ' ' && RSTRING_LEN(spat) == l) { split_type = awk; } } } } #define SPLIT_STR(beg, len) (empty_count = split_string(result, str, beg, len, empty_count)) if (result) result = rb_ary_new(); beg = 0; char *ptr = RSTRING_PTR(str); char *eptr = RSTRING_END(str); if (split_type == awk) { char *bptr = ptr; int skip = 1; unsigned int c; end = beg; if (is_ascii_string(str)) { while (ptr < eptr) { c = (unsigned char)*ptr++; if (skip) { if (ascii_isspace(c)) { beg = ptr - bptr; } else { end = ptr - bptr; skip = 0; if (!NIL_P(limit) && lim <= i) break; } } else if (ascii_isspace(c)) { SPLIT_STR(beg, end-beg); skip = 1; beg = ptr - bptr; if (!NIL_P(limit)) ++i; } else { end = ptr - bptr; } } } else { while (ptr < eptr) { int n; c = rb_enc_codepoint_len(ptr, eptr, &n, enc); ptr += n; if (skip) { if (rb_isspace(c)) { beg = ptr - bptr; } else { end = ptr - bptr; skip = 0; if (!NIL_P(limit) && lim <= i) break; } } else if (rb_isspace(c)) { SPLIT_STR(beg, end-beg); skip = 1; beg = ptr - bptr; if (!NIL_P(limit)) ++i; } else { end = ptr - bptr; } } } } else if (split_type == string) { char *str_start = ptr; char *substr_start = ptr; char *sptr = RSTRING_PTR(spat); long slen = RSTRING_LEN(spat); mustnot_broken(str); enc = rb_enc_check(str, spat); while (ptr < eptr && (end = rb_memsearch(sptr, slen, ptr, eptr - ptr, enc)) >= 0) { /* Check we are at the start of a char */ char *t = rb_enc_right_char_head(ptr, ptr + end, eptr, enc); if (t != ptr + end) { ptr = t; continue; } SPLIT_STR(substr_start - str_start, (ptr+end) - substr_start); ptr += end + slen; substr_start = ptr; if (!NIL_P(limit) && lim <= ++i) break; } beg = ptr - str_start; } else if (split_type == chars) { char *str_start = ptr; int n; mustnot_broken(str); enc = rb_enc_get(str); while (ptr < eptr && (n = rb_enc_precise_mbclen(ptr, eptr, enc)) > 0) { SPLIT_STR(ptr - str_start, n); ptr += n; if (!NIL_P(limit) && lim <= ++i) break; } beg = ptr - str_start; } else { long len = RSTRING_LEN(str); long start = beg; long idx; int last_null = 0; struct re_registers *regs; VALUE match = 0; for (; (end = rb_reg_search(spat, str, start, 0)) >= 0; (match ? (rb_match_unbusy(match), rb_backref_set(match)) : (void)0)) { match = rb_backref_get(); if (!result) rb_match_busy(match); regs = RMATCH_REGS(match); if (start == end && BEG(0) == END(0)) { if (!ptr) { SPLIT_STR(0, 0); break; } else if (last_null == 1) { SPLIT_STR(beg, rb_enc_fast_mbclen(ptr+beg, eptr, enc)); beg = start; } else { if (start == len) start++; else start += rb_enc_fast_mbclen(ptr+start,eptr,enc); last_null = 1; continue; } } else { SPLIT_STR(beg, end-beg); beg = start = END(0); } last_null = 0; for (idx=1; idx < regs->num_regs; idx++) { if (BEG(idx) == -1) continue; SPLIT_STR(BEG(idx), END(idx)-BEG(idx)); } if (!NIL_P(limit) && lim <= ++i) break; } if (match) rb_match_unbusy(match); } if (RSTRING_LEN(str) > 0 && (!NIL_P(limit) || RSTRING_LEN(str) > beg || lim < 0)) { SPLIT_STR(beg, RSTRING_LEN(str)-beg); } return result ? result : str; }
#squeeze([other_str]*) ⇒ String
Builds a set of characters from the other_str parameter(s) using the procedure described for #count. Returns a new string where runs of the same character that occur in this set are replaced by a single character. If no arguments are given, all runs of identical characters are replaced by a single character.
"yellow moon".squeeze #=> "yelow mon"
" now is the".squeeze(" ") #=> " now is the"
"putters shoot balls".squeeze("m-z") #=> "puters shot balls"
# File 'string.c', line 7636
static VALUE rb_str_squeeze(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_squeeze_bang(argc, argv, str); return str; }
#squeeze!([other_str]*) ⇒ String
?
Squeezes str in place, returning either str, or nil
if no changes were made.
# File 'string.c', line 7545
static VALUE rb_str_squeeze_bang(int argc, VALUE *argv, VALUE str) { char squeez[TR_TABLE_SIZE]; rb_encoding *enc = 0; VALUE del = 0, nodel = 0; unsigned char *s, *send, *t; int i, modify = 0; int ascompat, singlebyte = single_byte_optimizable(str); unsigned int save; if (argc == 0) { enc = STR_ENC_GET(str); } else { for (i=0; i<argc; i++) { VALUE s = argv[i]; StringValue(s); enc = rb_enc_check(str, s); if (singlebyte && !single_byte_optimizable(s)) singlebyte = 0; tr_setup_table(s, squeez, i==0, &del, &nodel, enc); } } str_modify_keep_cr(str); s = t = (unsigned char *)RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return Qnil; send = (unsigned char *)RSTRING_END(str); save = -1; ascompat = rb_enc_asciicompat(enc); if (singlebyte) { while (s < send) { unsigned int c = *s++; if (c != save || (argc > 0 && !squeez[c])) { *t++ = save = c; } } } else { while (s < send) { unsigned int c; int clen; if (ascompat && (c = *s) < 0x80) { if (c != save || (argc > 0 && !squeez[c])) { *t++ = save = c; } s++; } else { c = rb_enc_codepoint_len((char *)s, (char *)send, &clen, enc); if (c != save || (argc > 0 && !tr_find(c, squeez, del, nodel))) { if (t != s) rb_enc_mbcput(c, t, enc); save = c; t += clen; } s += clen; } } } TERM_FILL((char *)t, TERM_LEN(str)); if ((char *)t - RSTRING_PTR(str) != RSTRING_LEN(str)) { STR_SET_LEN(str, (char *)t - RSTRING_PTR(str)); modify = 1; } if (modify) return str; return Qnil; }
#start_with?([prefixes]+) ⇒ Boolean
Returns true if str
starts with one of the prefixes
given. Each of the prefixes
should be a String
or a ::Regexp
.
"hello".start_with?("hell") #=> true
"hello".start_with?(/H/i) #=> true
# returns true if one of the prefixes matches.
"hello".start_with?("heaven", "hell") #=> true
"hello".start_with?("heaven", "paradise") #=> false
# File 'string.c', line 9857
static VALUE rb_str_start_with(int argc, VALUE *argv, VALUE str) { int i; for (i=0; i<argc; i++) { VALUE tmp = argv[i]; if (RB_TYPE_P(tmp, T_REGEXP)) { if (rb_reg_start_with_p(tmp, str)) return Qtrue; } else { StringValue(tmp); rb_enc_check(str, tmp); if (RSTRING_LEN(str) < RSTRING_LEN(tmp)) continue; if (memcmp(RSTRING_PTR(str), RSTRING_PTR(tmp), RSTRING_LEN(tmp)) == 0) return Qtrue; } } return Qfalse; }
#strip ⇒ String
Returns a copy of the receiver with leading and trailing whitespace removed.
Whitespace is defined as any of the following characters: null, horizontal tab, line feed, vertical tab, form feed, carriage return, space.
" hello ".strip #=> "hello"
"\tgoodbye\r\n".strip #=> "goodbye"
"\x00\t\n\v\f\r ".strip #=> ""
"hello".strip #=> "hello"
# File 'string.c', line 9224
static VALUE rb_str_strip(VALUE str) { char *start; long olen, loffset, roffset; rb_encoding *enc = STR_ENC_GET(str); RSTRING_GETMEM(str, start, olen); loffset = lstrip_offset(str, start, start+olen, enc); roffset = rstrip_offset(str, start+loffset, start+olen, enc); if (loffset <= 0 && roffset <= 0) return rb_str_dup(str); return rb_str_subseq(str, loffset, olen-loffset-roffset); }
#strip! ⇒ self
?
Removes leading and trailing whitespace from the receiver. Returns the altered receiver, or nil
if there was no change.
Refer to #strip for the definition of whitespace.
" hello ".strip! #=> "hello"
"hello".strip! #=> nil
# File 'string.c', line 9180
static VALUE rb_str_strip_bang(VALUE str) { char *start; long olen, loffset, roffset; rb_encoding *enc; str_modify_keep_cr(str); enc = STR_ENC_GET(str); RSTRING_GETMEM(str, start, olen); loffset = lstrip_offset(str, start, start+olen, enc); roffset = rstrip_offset(str, start+loffset, start+olen, enc); if (loffset > 0 || roffset > 0) { long len = olen-roffset; if (loffset > 0) { len -= loffset; memmove(start, start + loffset, len); } STR_SET_LEN(str, len); #if !SHARABLE_MIDDLE_SUBSTRING TERM_FILL(start+len, rb_enc_mbminlen(enc)); #endif return str; } return Qnil; }
#sub(pattern, replacement) ⇒ String
#sub(pattern, hash) ⇒ String
#sub(pattern) {|match| ... } ⇒ String
String
#sub(pattern, hash) ⇒ String
#sub(pattern) {|match| ... } ⇒ String
Returns a copy of str
with the first occurrence of pattern
replaced by the second argument. The pattern
is typically a Regexp; if given as a String
, any regular expression metacharacters it contains will be interpreted literally, e.g. \d
will match a backslash followed by ‘d’, instead of a digit.
If replacement
is a String
it will be substituted for the matched text. It may contain back-references to the pattern’s capture groups of the form \d
, where d is a group number, or \k<n>
, where n is a group name. Similarly, \&
, \'
, \`
, and +
correspond to special variables, $&
, $'
, $`
, and $+
, respectively. (See regexp.rdoc for details.) \0
is the same as \&
. \\
is interpreted as an escape, i.e., a single backslash. Note that, within replacement
the special match variables, such as $&
, will not refer to the current match.
If the second argument is a ::Hash
, and the matched text is one of its keys, the corresponding value is the replacement string.
In the block form, the current match string is passed in as a parameter, and variables such as $1
, $2
, $`
, $&
, and $'
will be set appropriately. (See regexp.rdoc for details.) The value returned by the block will be substituted for the match on each call.
"hello".sub(/[aeiou]/, '*') #=> "h*llo"
"hello".sub(/([aeiou])/, '<\1>') #=> "h<e>llo"
"hello".sub(/./) {|s| s.ord.to_s + ' ' } #=> "104 ello"
"hello".sub(/(?<foo>[aeiou])/, '*\k<foo>*') #=> "h*e*llo"
'Is SHELL your preferred shell?'.sub(/[[:upper:]]{2,}/, ENV)
#=> "Is /bin/bash your preferred shell?"
Note that a string literal consumes backslashes. (See syntax/literals.rdoc for details about string literals.) Back-references are typically preceded by an additional backslash. For example, if you want to write a back-reference \&
in replacement
with a double-quoted string literal, you need to write: "..\\&.."
. If you want to write a non-back-reference string \&
in replacement
, you need first to escape the backslash to prevent this method from interpreting it as a back-reference, and then you need to escape the backslashes again to prevent a string literal from consuming them: "..\\\\&.."
. You may want to use the block form to avoid a lot of backslashes.
# File 'string.c', line 5131
static VALUE rb_str_sub(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_sub_bang(argc, argv, str); return str; }
#sub!(pattern, replacement) ⇒ String
?
#sub!(pattern) {|match| ... } ⇒ String
?
String
?
#sub!(pattern) {|match| ... } ⇒ String
?
Performs the same substitution as #sub in-place.
Returns str
if a substitution was performed or nil
if no substitution was performed.
# File 'string.c', line 4966
static VALUE rb_str_sub_bang(int argc, VALUE *argv, VALUE str) { VALUE pat, repl, hash = Qnil; int iter = 0; long plen; int min_arity = rb_block_given_p() ? 1 : 2; long beg; rb_check_arity(argc, min_arity, 2); if (argc == 1) { iter = 1; } else { repl = argv[1]; hash = rb_check_hash_type(argv[1]); if (NIL_P(hash)) { StringValue(repl); } } pat = get_pat_quoted(argv[0], 1); str_modifiable(str); beg = rb_pat_search(pat, str, 0, 1); if (beg >= 0) { rb_encoding *enc; int cr = ENC_CODERANGE(str); long beg0, end0; VALUE match, match0 = Qnil; struct re_registers *regs; char *p, *rp; long len, rlen; match = rb_backref_get(); regs = RMATCH_REGS(match); if (RB_TYPE_P(pat, T_STRING)) { beg0 = beg; end0 = beg0 + RSTRING_LEN(pat); match0 = pat; } else { beg0 = BEG(0); end0 = END(0); if (iter) match0 = rb_reg_nth_match(0, match); } if (iter || !NIL_P(hash)) { p = RSTRING_PTR(str); len = RSTRING_LEN(str); if (iter) { repl = rb_obj_as_string(rb_yield(match0)); } else { repl = rb_hash_aref(hash, rb_str_subseq(str, beg0, end0 - beg0)); repl = rb_obj_as_string(repl); } str_mod_check(str, p, len); rb_check_frozen(str); } else { repl = rb_reg_regsub(repl, str, regs, RB_TYPE_P(pat, T_STRING) ? Qnil : pat); } enc = rb_enc_compatible(str, repl); if (!enc) { rb_encoding *str_enc = STR_ENC_GET(str); p = RSTRING_PTR(str); len = RSTRING_LEN(str); if (coderange_scan(p, beg0, str_enc) != ENC_CODERANGE_7BIT || coderange_scan(p+end0, len-end0, str_enc) != ENC_CODERANGE_7BIT) { rb_raise(rb_eEncCompatError, "incompatible character encodings: %s and %s", rb_enc_name(str_enc), rb_enc_name(STR_ENC_GET(repl))); } enc = STR_ENC_GET(repl); } rb_str_modify(str); rb_enc_associate(str, enc); if (ENC_CODERANGE_UNKNOWN < cr && cr < ENC_CODERANGE_BROKEN) { int cr2 = ENC_CODERANGE(repl); if (cr2 == ENC_CODERANGE_BROKEN || (cr == ENC_CODERANGE_VALID && cr2 == ENC_CODERANGE_7BIT)) cr = ENC_CODERANGE_UNKNOWN; else cr = cr2; } plen = end0 - beg0; rlen = RSTRING_LEN(repl); len = RSTRING_LEN(str); if (rlen > plen) { RESIZE_CAPA(str, len + rlen - plen); } p = RSTRING_PTR(str); if (rlen != plen) { memmove(p + beg0 + rlen, p + beg0 + plen, len - beg0 - plen); } rp = RSTRING_PTR(repl); memmove(p + beg0, rp, rlen); len += rlen - plen; STR_SET_LEN(str, len); TERM_FILL(&RSTRING_PTR(str)[len], TERM_LEN(str)); ENC_CODERANGE_SET(str, cr); return str; } return Qnil; }
#succ ⇒ String
#next ⇒ String
String
#next ⇒ String
Alias for #next.
#succ! ⇒ String
#next! ⇒ String
String
#next! ⇒ String
Alias for #next!.
#sum(n = 16) ⇒ Integer
Returns a basic n-bit checksum of the characters in str, where n is the optional ::Integer
parameter, defaulting to 16. The result is simply the sum of the binary value of each byte in str modulo 2**n - 1
. This is not a particularly good checksum.
# File 'string.c', line 9545
static VALUE rb_str_sum(int argc, VALUE *argv, VALUE str) { int bits = 16; char *ptr, *p, *pend; long len; VALUE sum = INT2FIX(0); unsigned long sum0 = 0; if (rb_check_arity(argc, 0, 1) && (bits = NUM2INT(argv[0])) < 0) { bits = 0; } ptr = p = RSTRING_PTR(str); len = RSTRING_LEN(str); pend = p + len; while (p < pend) { if (FIXNUM_MAX - UCHAR_MAX < sum0) { sum = rb_funcall(sum, '+', 1, LONG2FIX(sum0)); str_mod_check(str, ptr, len); sum0 = 0; } sum0 += (unsigned char)*p; p++; } if (bits == 0) { if (sum0) { sum = rb_funcall(sum, '+', 1, LONG2FIX(sum0)); } } else { if (sum == INT2FIX(0)) { if (bits < (int)sizeof(long)*CHAR_BIT) { sum0 &= (((unsigned long)1)<<bits)-1; } sum = LONG2FIX(sum0); } else { VALUE mod; if (sum0) { sum = rb_funcall(sum, '+', 1, LONG2FIX(sum0)); } mod = rb_funcall(INT2FIX(1), idLTLT, 1, INT2FIX(bits)); mod = rb_funcall(mod, '-', 1, INT2FIX(1)); sum = rb_funcall(sum, '&', 1, mod); } } return sum; }
#swapcase ⇒ String
#swapcase([options]) ⇒ String
String
#swapcase([options]) ⇒ String
Returns a copy of str with uppercase alphabetic characters converted to lowercase and lowercase characters converted to uppercase.
See #downcase for meaning of options
and use with different encodings.
"Hello".swapcase #=> "hELLO"
"cYbEr_PuNk11".swapcase #=> "CyBeR_pUnK11"
# File 'string.c', line 6967
static VALUE rb_str_swapcase(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE | ONIGENC_CASE_DOWNCASE; VALUE ret; flags = check_case_options(argc, argv, flags); enc = str_true_enc(str); if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return str; if (flags&ONIGENC_CASE_ASCII_ONLY) { ret = rb_str_new_with_class(str, 0, RSTRING_LEN(str)); rb_str_ascii_casemap(str, ret, &flags, enc); } else { ret = rb_str_casemap(str, &flags, enc); } return ret; }
#swapcase! ⇒ String
?
#swapcase!([options]) ⇒ String
?
String
?
#swapcase!([options]) ⇒ String
?
# File 'string.c', line 6934
static VALUE rb_str_swapcase_bang(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE | ONIGENC_CASE_DOWNCASE; flags = check_case_options(argc, argv, flags); str_modify_keep_cr(str); enc = str_true_enc(str); if (flags&ONIGENC_CASE_ASCII_ONLY) rb_str_ascii_casemap(str, str, &flags, enc); else str_shared_replace(str, rb_str_casemap(str, &flags, enc)); if (ONIGENC_CASE_MODIFIED&flags) return str; return Qnil; }
#to_c ⇒ Complex
Returns a complex which denotes the string form. The parser ignores leading whitespaces and trailing garbage. Any digit sequences can be separated by an underscore. Returns zero for null or garbage string.
'9'.to_c #=> (9+0i)
'2.5'.to_c #=> (2.5+0i)
'2.5/1'.to_c #=> ((5/2)+0i)
'-3/2'.to_c #=> ((-3/2)+0i)
'-i'.to_c #=> (0-1i)
'45i'.to_c #=> (0+45i)
'3-4i'.to_c #=> (3-4i)
'-4e2-4e-2i'.to_c #=> (-400.0-0.04i)
'-0.0-0.0i'.to_c #=> (-0.0-0.0i)
'1/2+3/4i'.to_c #=> ((1/2)+(3/4)*i)
'ruby'.to_c #=> (0+0i)
See Kernel.Complex.
# File 'complex.c', line 2025
static VALUE string_to_c(VALUE self) { char *s; VALUE num; rb_must_asciicompat(self); s = RSTRING_PTR(self); if (s && s[RSTRING_LEN(self)]) { rb_str_modify(self); s = RSTRING_PTR(self); s[RSTRING_LEN(self)] = '\0'; } if (!s) s = (char *)""; (void)parse_comp(s, 0, &num); return num; }
#to_f ⇒ Float
Returns the result of interpreting leading characters in str as a floating point number. Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0.0
is returned. This method never raises an exception.
"123.45e1".to_f #=> 1234.5
"45.67 degrees".to_f #=> 45.67
"thx1138".to_f #=> 0.0
# File 'string.c', line 5774
static VALUE rb_str_to_f(VALUE str) { return DBL2NUM(rb_str_to_dbl(str, FALSE)); }
#to_i(base = 10) ⇒ Integer
Returns the result of interpreting leading characters in str as an integer base base (between 2 and 36). Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0
is returned. This method never raises an exception when base is valid.
"12345".to_i #=> 12345
"99 red balloons".to_i #=> 99
"0a".to_i #=> 0
"0a".to_i(16) #=> 10
"hello".to_i #=> 0
"1100101".to_i(2) #=> 101
"1100101".to_i(8) #=> 294977
"1100101".to_i(10) #=> 1100101
"1100101".to_i(16) #=> 17826049
# File 'string.c', line 5748
static VALUE rb_str_to_i(int argc, VALUE *argv, VALUE str) { int base = 10; if (rb_check_arity(argc, 0, 1) && (base = NUM2INT(argv[0])) < 0) { rb_raise(rb_eArgError, "invalid radix %d", base); } return rb_str_to_inum(str, base, FALSE); }
#to_r ⇒ Rational
Returns the result of interpreting leading characters in str
as a rational. Leading whitespace and extraneous characters past the end of a valid number are ignored. Digit sequences can be separated by an underscore. If there is not a valid number at the start of str
, zero is returned. This method never raises an exception.
' 2 '.to_r #=> (2/1)
'300/2'.to_r #=> (150/1)
'-9.2'.to_r #=> (-46/5)
'-9.2e2'.to_r #=> (-920/1)
'1_234_567'.to_r #=> (1234567/1)
'21 June 09'.to_r #=> (21/1)
'21/06/09'.to_r #=> (7/2)
'BWV 1079'.to_r #=> (0/1)
NOTE: “0.3”.to_r isn’t the same as 0.3.to_r. The former is equivalent to “3/10”.to_r, but the latter isn’t so.
"0.3".to_r == 3/10r #=> true
0.3.to_r == 3/10r #=> false
See also Kernel.Rational.
# File 'rational.c', line 2538
static VALUE string_to_r(VALUE self) { VALUE num; rb_must_asciicompat(self); num = parse_rat(RSTRING_PTR(self), RSTRING_END(self), 0, TRUE); if (RB_FLOAT_TYPE_P(num) && !FLOAT_ZERO_P(num)) rb_raise(rb_eFloatDomainError, "Infinity"); return num; }
#to_s ⇒ String
#to_str ⇒ String
Also known as: #to_str
String
#to_str ⇒ String
Returns self
.
If called on a subclass of String
, converts the receiver to a String
object.
# File 'string.c', line 5791
static VALUE rb_str_to_s(VALUE str) { if (rb_obj_class(str) != rb_cString) { return str_duplicate(rb_cString, str); } return str; }
#to_s ⇒ String
#to_str ⇒ String
String
#to_str ⇒ String
Alias for #to_s.
Alias for #intern.
#tr(from_str, to_str) ⇒ String
Returns a copy of str
with the characters in from_str
replaced by the corresponding characters in #to_str. If #to_str is shorter than from_str
, it is padded with its last character in order to maintain the correspondence.
"hello".tr('el', 'ip') #=> "hippo"
"hello".tr('aeiou', '*') #=> "h*ll*"
"hello".tr('aeiou', 'AA*') #=> "hAll*"
Both strings may use the c1-c2
notation to denote ranges of characters, and from_str
may start with a ^
, which denotes all characters except those listed.
"hello".tr('a-y', 'b-z') #=> "ifmmp"
"hello".tr('^aeiou', '*') #=> "*e**o"
The backslash character \
can be used to escape ^
or -
and is otherwise ignored unless it appears at the end of a range or the end of the from_str
or #to_str:
"hello^world".tr("\\^aeiou", "*") #=> "h*ll**w*rld"
"hello-world".tr("a\\-eo", "*") #=> "h*ll**w*rld"
"hello\r\nworld".tr("\r", "") #=> "hello\nworld"
"hello\r\nworld".tr("\\r", "") #=> "hello\r\nwold"
"hello\r\nworld".tr("\\\r", "") #=> "hello\nworld"
"X['\\b']".tr("X\\", "") #=> "['b']"
"X['\\b']".tr("X-\\]", "") #=> "'b'"
# File 'string.c', line 7349
static VALUE rb_str_tr(VALUE str, VALUE src, VALUE repl) { str = rb_str_dup(str); tr_trans(str, src, repl, 0); return str; }
#tr!(from_str, to_str) ⇒ String
?
Translates str in place, using the same rules as #tr. Returns str, or nil
if no changes were made.
# File 'string.c', line 7307
static VALUE rb_str_tr_bang(VALUE str, VALUE src, VALUE repl) { return tr_trans(str, src, repl, 0); }
#tr_s(from_str, to_str) ⇒ String
Processes a copy of str as described under #tr, then removes duplicate characters in regions that were affected by the translation.
"hello".tr_s('l', 'r') #=> "hero"
"hello".tr_s('el', '*') #=> "h*o"
"hello".tr_s('el', 'hx') #=> "hhxo"
# File 'string.c', line 7673
static VALUE rb_str_tr_s(VALUE str, VALUE src, VALUE repl) { str = rb_str_dup(str); tr_trans(str, src, repl, 1); return str; }
#tr_s!(from_str, to_str) ⇒ String
?
Performs #tr_s processing on str in place, returning str, or nil
if no changes were made.
# File 'string.c', line 7653
static VALUE rb_str_tr_s_bang(VALUE str, VALUE src, VALUE repl) { return tr_trans(str, src, repl, 1); }
#undump ⇒ String
Returns an unescaped version of the string. This does the inverse of #dump.
"\"hello \\n ''\"".undump #=> "hello \n ''"
# File 'string.c', line 6332
static VALUE str_undump(VALUE str) { const char *s = RSTRING_PTR(str); const char *s_end = RSTRING_END(str); rb_encoding *enc = rb_enc_get(str); VALUE undumped = rb_enc_str_new(s, 0L, enc); bool utf8 = false; bool binary = false; int w; rb_must_asciicompat(str); if (rb_str_is_ascii_only_p(str) == Qfalse) { rb_raise(rb_eRuntimeError, "non-ASCII character detected"); } if (!str_null_check(str, &w)) { rb_raise(rb_eRuntimeError, "string contains null byte"); } if (RSTRING_LEN(str) < 2) goto invalid_format; if (*s != '"') goto invalid_format; /* strip '"' at the start */ s++; for (;;) { if (s >= s_end) { rb_raise(rb_eRuntimeError, "unterminated dumped string"); } if (*s == '"') { /* epilogue */ s++; if (s == s_end) { /* ascii compatible dumped string */ break; } else { static const char force_encoding_suffix[] = ".force_encoding(\""; /* "\")" */ static const char dup_suffix[] = ".dup"; const char *encname; int encidx; ptrdiff_t size; /* check separately for strings dumped by older versions */ size = sizeof(dup_suffix) - 1; if (s_end - s > size && memcmp(s, dup_suffix, size) == 0) s += size; size = sizeof(force_encoding_suffix) - 1; if (s_end - s <= size) goto invalid_format; if (memcmp(s, force_encoding_suffix, size) != 0) goto invalid_format; s += size; if (utf8) { rb_raise(rb_eRuntimeError, "dumped string contained Unicode escape but used force_encoding"); } encname = s; s = memchr(s, '"', s_end-s); size = s - encname; if (!s) goto invalid_format; if (s_end - s != 2) goto invalid_format; if (s[0] != '"' || s[1] != ')') goto invalid_format; encidx = rb_enc_find_index2(encname, (long)size); if (encidx < 0) { rb_raise(rb_eRuntimeError, "dumped string has unknown encoding name"); } rb_enc_associate_index(undumped, encidx); } break; } if (*s == '\\') { s++; if (s >= s_end) { rb_raise(rb_eRuntimeError, "invalid escape"); } undump_after_backslash(undumped, &s, s_end, &enc, &utf8, &binary); } else { rb_str_cat(undumped, s++, 1); } } return undumped; invalid_format: rb_raise(rb_eRuntimeError, "invalid dumped string; not wrapped with '\"' nor '\"...\".force_encoding(\"...\")' form"); }
#unicode_normalize(form = :nfc)
Unicode Normalization—Returns a normalized form of str
, using Unicode normalizations NFC, NFD, NFKC, or NFKD. The normalization form used is determined by form
, which can be any of the four values :nfc
, :nfd
, :nfkc
, or :nfkd
. The default is :nfc
.
If the string is not in a Unicode Encoding, then an ::Exception
is raised. In this context, ‘Unicode Encoding’ means any of UTF-8, UTF-16BE/LE, and UTF-32BE/LE, as well as GB18030, UCS_2BE, and UCS_4BE. Anything other than UTF-8 is implemented by converting to UTF-8, which makes it slower than UTF-8.
"a\u0300".unicode_normalize #=> "\u00E0"
"a\u0300".unicode_normalize(:nfc) #=> "\u00E0"
"\u00E0".unicode_normalize(:nfd) #=> "a\u0300"
"\xE0".force_encoding('ISO-8859-1').unicode_normalize(:nfd)
#=> Encoding::CompatibilityError raised
# File 'string.c', line 10594
static VALUE rb_str_unicode_normalize(int argc, VALUE *argv, VALUE str) { return unicode_normalize_common(argc, argv, str, id_normalize); }
#unicode_normalize!(form = :nfc)
Destructive version of #unicode_normalize, doing Unicode normalization in place.
# File 'string.c', line 10607
static VALUE rb_str_unicode_normalize_bang(int argc, VALUE *argv, VALUE str) { return rb_str_replace(str, unicode_normalize_common(argc, argv, str, id_normalize)); }
#unicode_normalized?(form = :nfc)
Checks whether str
is in Unicode normalization form form
, which can be any of the four values :nfc
, :nfd
, :nfkc
, or :nfkd
. The default is :nfc
.
If the string is not in a Unicode Encoding, then an ::Exception
is raised. For details, see #unicode_normalize.
"a\u0300".unicode_normalized? #=> false
"a\u0300".unicode_normalized?(:nfd) #=> true
"\u00E0".unicode_normalized? #=> true
"\u00E0".unicode_normalized?(:nfd) #=> false
"\xE0".force_encoding('ISO-8859-1').unicode_normalized?
#=> Encoding::CompatibilityError raised
# File 'string.c', line 10630
static VALUE rb_str_unicode_normalized_p(int argc, VALUE *argv, VALUE str) { return unicode_normalize_common(argc, argv, str, id_normalized_p); }
#unpack(format) ⇒ Array
Decodes str (which may contain binary data) according to the format string, returning an array of each value extracted. The format string consists of a sequence of single-character directives, summarized in the table at the end of this entry. Each directive may be followed by a number, indicating the number of times to repeat with this directive. An asterisk (“*
”) will use up all remaining elements. The directives sSiIlL
may each be followed by an underscore (“_
”) or exclamation mark (“!
”) to use the underlying platform’s native size for the specified type; otherwise, it uses a platform-independent consistent size. Spaces are ignored in the format string. See also #unpack1, Array#pack.
"abc \0\0abc \0\0".unpack('A6Z6') #=> ["abc", "abc "]
"abc \0\0".unpack('a3a3') #=> ["abc", " \000\000"]
"abc \0abc \0".unpack('Z*Z*') #=> ["abc ", "abc "]
"aa".unpack('b8B8') #=> ["10000110", "01100001"]
"aaa".unpack('h2H2c') #=> ["16", "61", 97]
"\xfe\xff\xfe\xff".unpack('sS') #=> [-2, 65534]
"now=20is".unpack('M*') #=> ["now is"]
"whole".unpack('xax2aX2aX1aX2a') #=> ["h", "e", "l", "l", "o"]
This table summarizes the various formats and the Ruby classes returned by each.
Integer | |
Directive | Returns | Meaning
------------------------------------------------------------------
C | Integer | 8-bit unsigned (unsigned char)
S | Integer | 16-bit unsigned, native endian (uint16_t)
L | Integer | 32-bit unsigned, native endian (uint32_t)
Q | Integer | 64-bit unsigned, native endian (uint64_t)
J | Integer | pointer width unsigned, native endian (uintptr_t)
| |
c | Integer | 8-bit signed (signed char)
s | Integer | 16-bit signed, native endian (int16_t)
l | Integer | 32-bit signed, native endian (int32_t)
q | Integer | 64-bit signed, native endian (int64_t)
j | Integer | pointer width signed, native endian (intptr_t)
| |
S_ S! | Integer | unsigned short, native endian
I I_ I! | Integer | unsigned int, native endian
L_ L! | Integer | unsigned long, native endian
Q_ Q! | Integer | unsigned long long, native endian (ArgumentError
| | if the platform has no long long type.)
J! | Integer | uintptr_t, native endian (same with J)
| |
s_ s! | Integer | signed short, native endian
i i_ i! | Integer | signed int, native endian
l_ l! | Integer | signed long, native endian
q_ q! | Integer | signed long long, native endian (ArgumentError
| | if the platform has no long long type.)
j! | Integer | intptr_t, native endian (same with j)
| |
S> s> S!> s!> | Integer | same as the directives without ">" except
L> l> L!> l!> | | big endian
I!> i!> | |
Q> q> Q!> q!> | | "S>" is same as "n"
J> j> J!> j!> | | "L>" is same as "N"
| |
S< s< S!< s!< | Integer | same as the directives without "<" except
L< l< L!< l!< | | little endian
I!< i!< | |
Q< q< Q!< q!< | | "S<" is same as "v"
J< j< J!< j!< | | "L<" is same as "V"
| |
n | Integer | 16-bit unsigned, network (big-endian) byte order
N | Integer | 32-bit unsigned, network (big-endian) byte order
v | Integer | 16-bit unsigned, VAX (little-endian) byte order
V | Integer | 32-bit unsigned, VAX (little-endian) byte order
| |
U | Integer | UTF-8 character
w | Integer | BER-compressed integer (see Array.pack)
Float | |
Directive | Returns | Meaning
-----------------------------------------------------------------
D d | Float | double-precision, native format
F f | Float | single-precision, native format
E | Float | double-precision, little-endian byte order
e | Float | single-precision, little-endian byte order
G | Float | double-precision, network (big-endian) byte order
g | Float | single-precision, network (big-endian) byte order
String | |
Directive | Returns | Meaning
-----------------------------------------------------------------
A | String | arbitrary binary string (remove trailing nulls and ASCII spaces)
a | String | arbitrary binary string
Z | String | null-terminated string
B | String | bit string (MSB first)
b | String | bit string (LSB first)
H | String | hex string (high nibble first)
h | String | hex string (low nibble first)
u | String | UU-encoded string
M | String | quoted-printable, MIME encoding (see RFC2045)
m | String | base64 encoded string (RFC 2045) (default)
| | base64 encoded string (RFC 4648) if followed by 0
P | String | pointer to a structure (fixed-length string)
p | String | pointer to a null-terminated string
Misc. | |
Directive | Returns | Meaning
-----------------------------------------------------------------
@ | --- | skip to the offset given by the length argument
X | --- | skip backward one byte
x | --- | skip forward one byte
HISTORY
-
J, J! j, and j! are available since Ruby 2.3.
-
Q_, Q!, q_, and q! are available since Ruby 2.1.
-
I!<, i!<, I!>, and i!> are available since Ruby 1.9.3.
# File 'pack.rb', line 256
def unpack(fmt) __builtin_pack_unpack(fmt) end
#unpack1(format) ⇒ Object
Decodes str (which may contain binary data) according to the format string, returning the first value extracted. See also #unpack, Array#pack.
Contrast with #unpack:
"abc \0\0abc \0\0".unpack('A6Z6') #=> ["abc", "abc "]
"abc \0\0abc \0\0".unpack1('A6Z6') #=> "abc"
In that case data would be lost but often it’s the case that the array only holds one value, especially when unpacking binary data. For instance:
“xffx00x00x00”.unpack(“l”) #=> [255] “xffx00x00x00”.unpack1(“l”) #=> 255
Thus unpack1 is convenient, makes clear the intention and signals the expected return value to those reading the code.
# File 'pack.rb', line 280
def unpack1(fmt) __builtin_pack_unpack1(fmt) end
#upcase ⇒ String
#upcase([options]) ⇒ String
String
#upcase([options]) ⇒ String
Returns a copy of str with all lowercase letters replaced with their uppercase counterparts.
See #downcase for meaning of options
and use with different encodings.
"hEllO".upcase #=> "HELLO"
# File 'string.c', line 6694
static VALUE rb_str_upcase(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE; VALUE ret; flags = check_case_options(argc, argv, flags); enc = str_true_enc(str); if (case_option_single_p(flags, enc, str)) { ret = rb_str_new_with_class(str, RSTRING_PTR(str), RSTRING_LEN(str)); str_enc_copy(ret, str); upcase_single(ret); } else if (flags&ONIGENC_CASE_ASCII_ONLY) { ret = rb_str_new_with_class(str, 0, RSTRING_LEN(str)); rb_str_ascii_casemap(str, ret, &flags, enc); } else { ret = rb_str_casemap(str, &flags, enc); } return ret; }
#upcase! ⇒ String
?
#upcase!([options]) ⇒ String
?
String
?
#upcase!([options]) ⇒ String
?
Upcases the contents of str, returning nil
if no changes were made.
See #downcase for meaning of options
and use with different encodings.
# File 'string.c', line 6658
static VALUE rb_str_upcase_bang(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; OnigCaseFoldType flags = ONIGENC_CASE_UPCASE; flags = check_case_options(argc, argv, flags); str_modify_keep_cr(str); enc = str_true_enc(str); if (case_option_single_p(flags, enc, str)) { if (upcase_single(str)) flags |= ONIGENC_CASE_MODIFIED; } else if (flags&ONIGENC_CASE_ASCII_ONLY) rb_str_ascii_casemap(str, str, &flags, enc); else str_shared_replace(str, rb_str_casemap(str, &flags, enc)); if (ONIGENC_CASE_MODIFIED&flags) return str; return Qnil; }
#upto(other_str, exclusive = false) {|s| ... } ⇒ String
#upto(other_str, exclusive = false) ⇒ Enumerator
String
#upto(other_str, exclusive = false) ⇒ Enumerator
Iterates through successive values, starting at str and ending at other_str inclusive, passing each value in turn to the block. The #succ method is used to generate each value. If optional second argument exclusive is omitted or is false, the last value will be included; otherwise it will be excluded.
If no block is given, an enumerator is returned instead.
"a8".upto("b6") {|s| print s, ' ' }
for s in "a8".."b6"
print s, ' '
end
produces:
a8 a9 b0 b1 b2 b3 b4 b5 b6
a8 a9 b0 b1 b2 b3 b4 b5 b6
If str and other_str contains only ascii numeric characters, both are recognized as decimal numbers. In addition, the width of string (e.g. leading zeros) is handled appropriately.
"9".upto("11").to_a #=> ["9", "10", "11"]
"25".upto("5").to_a #=> []
"07".upto("11").to_a #=> ["07", "08", "09", "10", "11"]
# File 'string.c', line 4252
static VALUE rb_str_upto(int argc, VALUE *argv, VALUE beg) { VALUE end, exclusive; rb_scan_args(argc, argv, "11", &end, &exclusive); RETURN_ENUMERATOR(beg, argc, argv); return rb_str_upto_each(beg, end, RTEST(exclusive), str_upto_i, Qnil); }