Top Level Namespace
Relationships & Source Files | |
Namespace Children | |
Modules:
| |
Classes:
ARGF ,
Array ,
BasicObject ,
Binding ,
Class ,
Complex ,
Continuation ,
Data ,
Dir ,
ENV ,
Encoding ,
Enumerator ,
FalseClass ,
Fiber ,
File ,
Float ,
Hash ,
IO ,
Integer ,
MatchData ,
Method ,
Module ,
NilClass ,
Numeric ,
Object ,
Proc ,
Ractor ,
Random ,
Range ,
Rational ,
Refinement ,
Regexp ,
RubyVM ,
String ,
Struct ,
Symbol ,
Thread ,
ThreadGroup ,
Time ,
TracePoint ,
TrueClass ,
UnboundMethod | |
Exceptions:
ArgumentError ,
ClosedQueueError ,
EOFError ,
EncodingError ,
Exception ,
FiberError ,
FloatDomainError ,
FrozenError ,
IOError ,
IndexError ,
Interrupt ,
KeyError ,
LoadError ,
LocalJumpError ,
NameError ,
NoMatchingPatternError ,
NoMatchingPatternKeyError ,
NoMemoryError ,
NoMethodError ,
NotImplementedError ,
RangeError ,
RegexpError ,
RuntimeError ,
ScriptError ,
SecurityError ,
SignalException ,
StandardError ,
StopIteration ,
SyntaxError ,
SystemCallError ,
SystemExit ,
SystemStackError ,
ThreadError ,
TypeError ,
UncaughtThrowError ,
ZeroDivisionError ,
fatal |
Constant Summary
-
ARGV =
ARGV
contains the command line arguments used to run ruby.A library like OptionParser can be used to process command-line arguments.
rb_argv
-
DATA =
# File 'ruby.c', line 2188rb_stdin
-
RUBY_COPYRIGHT =
The copyright string for ruby
MKSTR(copyright)
-
RUBY_DESCRIPTION =
MKSTR(description)
/* MKSTR(description) */ description
-
RUBY_ENGINE =
MKSTR(engine)
/* MKSTR(engine) */ ruby_engine_name
-
RUBY_ENGINE_VERSION =
MKSTR(version)
/* MKSTR(version) */ version
-
RUBY_PATCHLEVEL =
The patchlevel for this ruby. If this is a development build of ruby the patchlevel will be -1
MKINT(patchlevel)
-
RUBY_PLATFORM =
The platform for this ruby
MKSTR(platform)
-
RUBY_RELEASE_DATE =
The date this ruby was released
MKSTR(release_date)
-
RUBY_REVISION =
The GIT commit hash for this ruby.
MKSTR(revision)
-
RUBY_VERSION =
MKSTR(version)
/* MKSTR(version) */ version
-
STDERR =
Holds the original stderr
rb_stderr
-
STDIN =
Holds the original stdin
rb_stdin
-
STDOUT =
Holds the original stdout
rb_stdout
-
TOPLEVEL_BINDING =
The Binding of the top level scope
rb_binding_new()
Class Attribute Summary
- $!(*_) readonly
- $$(*_y) readonly
- $&(*_y) readonly
- $'(*_y) readonly
- $*(*var) readonly
- $+(*_y) readonly
- $, rw
-
$-0
rw
Alias for $/.
-
$-d(*dmy)
rw
Alias for $DEBUG.
-
$-F
rw
Alias for $;.
- $-i(*var) rw
-
$-v(*ptr)
rw
Alias for $VERBOSE.
-
$-w(*ptr)
rw
Alias for $VERBOSE.
- $-W(*dmy) rw
- $.(*var) rw
- $/ (also: .$-0) rw
- $0 (also: .$PROGRAM_NAME) rw
- $; (also: .$-F) rw
- $< readonly
- $=(*_y) rw
-
$>(*ptr)
rw
Alias for $stdout.
- $@(*_) rw
- $\(*_y) (also: .$LOADED_FEATURES) readonly
- $\\ rw
- $_(*_y) rw
- $`(*_y) readonly
- $DEBUG(*dmy) (also: .$-d) rw
- $FILENAME(*var) readonly
- $find_time_numguess(*data) readonly
-
$LOADED_FEATURES(*_y)
readonly
Alias for $.
-
$PROGRAM_NAME
rw
Alias for $0.
- $stderr(*ptr) rw
- $stdin(*ptr) rw
- $stdout(*ptr) (also: .$>) rw
- $VERBOSE(*ptr) (also: .$-v, .$-w) rw
- $~(*_y) rw
Class Method Summary
-
$?(*_y) ⇒ Boolean
Module
Process
represents a process in the underlying operating system.
Class Attribute Details
$!(*_) (readonly)
[ GitHub ]# File 'eval.c', line 1928
static VALUE errinfo_getter(ID id, VALUE *_) { return get_errinfo(); }
$$(*_y) (readonly)
[ GitHub ]# File 'process.c', line 8727
static VALUE get_PROCESS_ID(ID _x, VALUE *_y) { return get_pid(); }
$&(*_y) (readonly)
[ GitHub ]# File 're.c', line 2036
static VALUE last_match_getter(ID _x, VALUE *_y) { return rb_reg_last_match(rb_backref_get()); }
$'(*_y) (readonly)
[ GitHub ]# File 're.c', line 2048
static VALUE postmatch_getter(ID _x, VALUE *_y) { return rb_reg_match_post(rb_backref_get()); }
$*(*var) (readonly)
[ GitHub ]# File 'io.c', line 14577
static VALUE argf_argv_getter(ID id, VALUE *var) { return argf_argv(*var); }
$+(*_y) (readonly)
[ GitHub ]# File 're.c', line 2054
static VALUE last_paren_match_getter(ID _x, VALUE *_y) { return rb_reg_match_last(rb_backref_get()); }
$, (rw)
[ GitHub ]# File 'io.c', line 15662
rb_define_hooked_variable("$,", &rb_output_fs, 0, deprecated_str_setter);
$-0 (rw)
Alias for $/.
# File 'io.c', line 15669
rb_define_hooked_variable("$-0", &rb_rs, 0, deprecated_str_setter);
$-d(*dmy) (rw)
Alias for $DEBUG.
$-F (rw)
Alias for $;.
# File 'string.c', line 12720
rb_define_hooked_variable("$-F", &rb_fs, 0, rb_fs_setter);
$-i(*var) (rw)
[ GitHub ]# File 'io.c', line 14503
static VALUE opt_i_get(ID id, VALUE *var) { return argf_inplace_mode_get(*var); }
$-v(*ptr) (rw)
Alias for $VERBOSE.
$-W(*dmy) (rw)
[ GitHub ]# File 'ruby.c', line 3060
static VALUE opt_W_getter(ID id, VALUE *dmy) { VALUE v = *rb_ruby_verbose_ptr(); switch (v) { case Qnil: return INT2FIX(0); case Qfalse: return INT2FIX(1); case Qtrue: return INT2FIX(2); default: return Qnil; } }
$-w(*ptr) (rw)
Alias for $VERBOSE.
$.(*var) (rw)
[ GitHub ]# File 'io.c', line 10269
static VALUE argf_lineno_getter(ID id, VALUE *var) { VALUE argf = *var; return INT2FIX(ARGF.last_lineno); }
$/ (rw) Also known as: ::$-0
[ GitHub ]# File 'io.c', line 15668
rb_define_hooked_variable("$/", &rb_rs, 0, deprecated_str_setter);
$0 (rw) Also known as: ::$PROGRAM_NAME
[ GitHub ]# File 'ruby.c', line 3106
rb_define_hooked_variable("$0", &rb_progname, 0, set_arg0);
$; (rw) Also known as: ::$-F
[ GitHub ]# File 'string.c', line 12719
rb_define_hooked_variable("$;", &rb_fs, 0, rb_fs_setter);
$< (readonly)
[ GitHub ]# File 'io.c', line 15884
rb_define_readonly_variable("$<", &argf);
$=(*_y) (rw)
[ GitHub ]# File 're.c', line 4566
static VALUE ignorecase_getter(ID _x, VALUE *_y) { rb_category_warn(RB_WARN_CATEGORY_DEPRECATED, "variable $= is no longer effective"); return Qfalse; }
$>(*ptr) (rw)
Alias for $stdout.
$@(*_) (rw)
[ GitHub ]# File 'eval.c', line 1949
static VALUE errat_getter(ID id, VALUE *_) { VALUE err = get_errinfo(); if (!NIL_P(err)) { return rb_get_backtrace(err); } else { return Qnil; } }
$\(*_y) (readonly) Also known as: ::$LOADED_FEATURES
[ GitHub ]# File 'load.c', line 188
static VALUE get_LOADED_FEATURES(ID _x, VALUE *_y) { return get_loaded_features(GET_VM()); }
$\\ (rw)
[ GitHub ]# File 'io.c', line 15670
rb_define_hooked_variable("$\\", &rb_output_rs, 0, deprecated_str_setter);
$_(*_y) (rw)
[ GitHub ]# File 'io.c', line 14669
static VALUE get_LAST_READ_LINE(ID _x, VALUE *_y) { return rb_lastline_get(); }
$`(*_y) (readonly)
[ GitHub ]# File 're.c', line 2042
static VALUE prematch_getter(ID _x, VALUE *_y) { return rb_reg_match_pre(rb_backref_get()); }
$DEBUG(*dmy) (rw) Also known as: ::$-d
[ GitHub ]# File 'ruby.c', line 3077
static VALUE debug_getter(ID id, VALUE *dmy) { return *rb_ruby_debug_ptr(); }
$FILENAME(*var) (readonly)
[ GitHub ]# File 'io.c', line 14336
static VALUE argf_filename_getter(ID id, VALUE *var) { return argf_filename(*var); }
$find_time_numguess(*data) (readonly)
[ GitHub ]# File 'time.c', line 3280
static VALUE find_time_numguess_getter(ID name, VALUE *data) { unsigned long long *numguess = (void *)data; return ULL2NUM(*numguess); }
$LOADED_FEATURES(*_y) (readonly)
Alias for $.
$PROGRAM_NAME (rw)
Alias for $0.
# File 'ruby.c', line 3107
rb_define_hooked_variable("$PROGRAM_NAME", &rb_progname, 0, set_arg0);
$stderr(*ptr) (rw)
[ GitHub ]# File 'io.c', line 9197
static VALUE stderr_getter(ID id, VALUE *ptr) { return rb_ractor_stderr(); }
$stdin(*ptr) (rw)
[ GitHub ]# File 'io.c', line 9171
static VALUE stdin_getter(ID id, VALUE *ptr) { return rb_ractor_stdin(); }
$stdout(*ptr) (rw) Also known as: ::$>
[ GitHub ]# File 'io.c', line 9184
static VALUE stdout_getter(ID id, VALUE *ptr) { return rb_ractor_stdout(); }
$VERBOSE(*ptr) (rw) Also known as: ::$-v, ::$-w
[ GitHub ]# File 'ruby.c', line 3048
static VALUE verbose_getter(ID id, VALUE *ptr) { return *rb_ruby_verbose_ptr(); }
$~(*_y) (rw)
[ GitHub ]# File 're.c', line 4589
static VALUE get_LAST_MATCH_INFO(ID _x, VALUE *_y) { return match_getter(); }
Class Method Details
$?(*_y) ⇒ Boolean
Module ::Process
represents a process in the underlying operating system. Its methods support management of the current process and its child processes.
Process Creation
Each of the following methods executes a given command in a new process or subshell, or multiple commands in new processes and/or subshells. The choice of process or subshell depends on the form of the command; see Argument command_line or exe_path
.
-
Process.spawn, Kernel.spawn: Executes the command; returns the new pid without waiting for completion.
-
Process.exec: Replaces the current process by executing the command.
In addition:
-
Method Kernel.system executes a given command-line (string) in a subshell; returns
true
,false
, ornil
. -
Method
Kernel.‘
executes a given command-line (string) in a subshell; returns its $stdout string. -
Module Open3 supports creating child processes with access to their $stdin, $stdout, and $stderr streams.
Execution Environment
Optional leading argument env
is a hash of name/value pairs, where each name is a string and each value is a string or nil
; each name/value pair is added to ::ENV
in the new process.
Process.spawn( 'ruby -e "p ENV[\"Foo\"]"')
Process.spawn({'Foo' => '0'}, 'ruby -e "p ENV[\"Foo\"]"')
Output:
"0"
The effect is usually similar to that of calling ENV#update
with argument env
, where each named environment variable is created or updated (if the value is non-nil
), or deleted (if the value is nil
).
However, some modifications to the calling process may remain if the new process fails. For example, hard resource limits are not restored.
Argument command_line
or exe_path
The required string argument is one of the following:
-
command_line
if it begins with a shell reserved word or special built-in, or if it contains one or more meta characters. -
exe_path
otherwise.
Argument command_line
String argument command_line
is a command line to be passed to a shell; it must begin with a shell reserved word, begin with a special built-in, or contain meta characters:
system('if true; then echo "Foo"; fi') # => true # Shell reserved word.
system('exit') # => true # Built-in.
system('date > /tmp/date.tmp') # => true # Contains meta character.
system('date > /nop/date.tmp') # => false
system('date > /nop/date.tmp', exception: true) # Raises RuntimeError.
The command line may also contain arguments and options for the command:
system('echo "Foo"') # => true
Output:
Foo
See Execution Shell
for details about the shell.
Argument exe_path
Argument exe_path
is one of the following:
-
The string path to an executable file to be called:
Example:
system('/usr/bin/date') # => true # Path to date on Unix-style system. system('foo') # => nil # Command execlution failed.
Output:
Thu Aug 31 10:06:48 AM CDT 2023
A path or command name containing spaces without arguments cannot be distinguished from
command_line
above, so you must quote or escape the entire command name using a shell in platform dependent manner, or use the array form below.If
exe_path
does not contain any path separator, an executable file is searched from directories specified with thePATH
environment variable. What the word “executable” means here is depending on platforms.Even if the file considered “executable”, its content may not be in proper executable format. In that case, Ruby tries to run it by using
/bin/sh
on a Unix-like system, like system(3) does.File.write('shell_command', 'echo $SHELL', perm: 0o755) system('./shell_command') # prints "/bin/sh" or something.
-
A 2-element array containing the path to an executable and the string to be used as the name of the executing process:
Example:
pid = spawn(['sleep', 'Hello!'], '1') # 2-element array. p `ps -p #{pid} -o command=`
Output:
"Hello! 1\n"
Arguments args
If command_line
does not contain shell meta characters except for spaces and tabs, or exe_path
is given, Ruby invokes the executable directly. This form does not use the shell:
spawn("doesnt_exist") # Raises Errno::ENOENT
spawn("doesnt_exist", "\n") # Raises Errno::ENOENT
spawn("doesnt_exist\n") # => false
# sh: 1: doesnot_exist: not found
The error message is from a shell and would vary depending on your system.
If one or more args
is given after exe_path
, each is an argument or option to be passed to the executable:
Example:
system('echo', '<', 'C*', '|', '$SHELL', '>') # => true
Output:
< C* | $SHELL >
However, there are exceptions on Windows. See Execution Shell on Windows.
If you want to invoke a path containing spaces with no arguments without shell, you will need to use a 2-element array exe_path
.
Example:
path = '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome'
spawn(path) # Raises Errno::ENOENT; No such file or directory - /Applications/Google
spawn([path] * 2)
Execution Options
Optional trailing argument options
is a hash of execution options.
Working Directory (:chdir
)
By default, the working directory for the new process is the same as that of the current process:
Dir.chdir('/var')
Process.spawn('ruby -e "puts Dir.pwd"')
Output:
/var
Use option :chdir
to set the working directory for the new process:
Process.spawn('ruby -e "puts Dir.pwd"', {chdir: '/tmp'})
Output:
/tmp
The working directory of the current process is not changed:
Dir.pwd # => "/var"
File Redirection (File Descriptor)
Use execution options for file redirection in the new process.
The key for such an option may be an integer file descriptor (fd), specifying a source, or an array of fds, specifying multiple sources.
An integer source fd may be specified as:
-
n: Specifies file descriptor n.
There are these shorthand symbols for fds:
-
:in
: Specifies file descriptor 0 (STDIN). -
:out
: Specifies file descriptor 1 (STDOUT). -
:err
: Specifies file descriptor 2 (STDERR).
The value given with a source is one of:
-
n: Redirects to fd n in the parent process.
-
filepath
: Redirects from or to the file atfilepath
viaopen(filepath, mode, 0644)
, wheremode
is'r'
for source:in
, or'w'
for source:out
or:err
. -
[filepath]
: Redirects from the file atfilepath
viaopen(filepath, 'r', 0644)
. -
[filepath, mode]
: Redirects from or to the file atfilepath
viaopen(filepath, mode, 0644)
. -
[filepath, mode, perm]
: Redirects from or to the file atfilepath
viaopen(filepath, mode, perm)
. -
[:child, fd]
: Redirects to the redirectedfd
. -
:close
: Closes the file descriptor in child process.
See Access Modes
and {File
Permissions}.
Environment Variables (:unsetenv_others
)
By default, the new process inherits environment variables from the parent process; use execution option key :unsetenv_others
with value true
to clear environment variables in the new process.
Any changes specified by execution option env
are made after the new process inherits or clears its environment variables; see Execution Environment
.
File-Creation Access (:umask
)
Use execution option :umask
to set the file-creation access for the new process; see Access Modes
:
command = 'ruby -e "puts sprintf(\"0%o\", File.umask)"'
= {:umask => 0644}
Process.spawn(command, )
Output:
0644
Process Groups (:pgroup
and :new_pgroup
)
By default, the new process belongs to the same process group as the parent process.
To specify a different process group. use execution option :pgroup
with one of the following values:
-
true
: Create a new process group for the new process. -
pgid: Create the new process in the process group whose id is pgid.
On Windows only, use execution option :new_pgroup
with value true
to create a new process group for the new process.
Resource Limits
Use execution options to set resource limits.
The keys for these options are symbols of the form :rlimit_resource_name
, where resource_name is the downcased form of one of the string resource names described at method Process.setrlimit. For example, key :rlimit_cpu
corresponds to resource limit 'CPU'
.
The value for such as key is one of:
-
An integer, specifying both the current and maximum limits.
-
A 2-element array of integers, specifying the current and maximum limits.
File Descriptor Inheritance
By default, the new process inherits file descriptors from the parent process.
Use execution option :close_others => true
to modify that inheritance by closing non-standard fds (3 and greater) that are not otherwise redirected.
Execution Shell
On a Unix-like system, the shell invoked is /bin/sh
; the entire string command_line
is passed as an argument to shell option -c.
The shell performs normal shell expansion on the command line:
Example:
system('echo $SHELL: C*') # => true
Output:
/bin/bash: CONTRIBUTING.md COPYING COPYING.ja
Execution Shell on Windows
On Windows, the shell invoked is determined by environment variable RUBYSHELL
, if defined, or COMSPEC
otherwise; the entire string command_line
is passed as an argument to -c
option for RUBYSHELL
, as well as /bin/sh
, and /c option for COMSPEC
. The shell is invoked automatically in the following cases:
-
The command is a built-in of
cmd.exe
, such asecho
. -
The executable file is a batch file; its name ends with
.bat
or.cmd
.
Note that the command will still be invoked as command_line
form even when called in exe_path
form, because cmd.exe
does not accept a script name like /bin/sh
does but only works with /c
option.
The standard shell cmd.exe
performs environment variable expansion but does not have globbing functionality:
Example:
system("echo %COMSPEC%: C*")' # => true
Output:
C:\WINDOWS\system32\cmd.exe: C*
What’s Here
Current-Process Getters
-
.argv0
: Returns the process name as a frozen string. -
.egid
: Returns the effective group ID. -
.euid
: Returns the effective user ID. -
.getpgrp
: Return the process group ID. -
.getrlimit
: Returns the resource limit. -
.gid
: Returns the (real) group ID. -
.pid
: Returns the process ID. -
.ppid
: Returns the process ID of the parent process. -
.uid
: Returns the (real) user ID.
Current-Process Setters
-
.egid=
: Sets the effective group ID. -
.euid=
: Sets the effective user ID. -
.gid=
: Sets the (real) group ID. -
.setproctitle
: Sets the process title. -
.setpgrp
: Sets the process group ID of the process to zero. -
.setrlimit
: Sets a resource limit. -
.setsid
: Establishes the process as a new session and process group leader, with no controlling tty. -
.uid=
: Sets the user ID.
Current-Process Execution
-
.abort
: Immediately terminates the process. -
.daemon
: Detaches the process from its controlling terminal and continues running it in the background as system daemon. -
.exec
: Replaces the process by running a given external command. -
.exit
: Initiates process termination by raising exception::SystemExit
(which may be caught). -
.exit!
: Immediately exits the process. -
.warmup
: Notifies the Ruby virtual machine that the boot sequence for the application is completed, and that the VM may begin optimizing the application.
Child Processes
-
.detach
: Guards against a child process becoming a zombie. -
.fork
: Creates a child process. -
.kill
: Sends a given signal to processes. -
.spawn
: Creates a child process. -
.wait
,.waitpid
: Waits for a child process to exit; returns its process ID. -
.wait2
,.waitpid2
: Waits for a child process to exit; returns its process ID and status. -
.waitall
: Waits for all child processes to exit; returns their process IDs and statuses.
Process Groups
-
.getpgid
: Returns the process group ID for a process. -
.getpriority
: Returns the scheduling priority for a process, process group, or user. -
.getsid
: Returns the session ID for a process. -
.groups
: Returns an array of the group IDs in the supplemental group access list for this process. -
.groups=
: Sets the supplemental group access list to the given array of group IDs. -
.initgroups
: Initializes the supplemental group access list. -
.last_status
: Returns the status of the last executed child process in the current thread. -
.maxgroups
: Returns the maximum number of group IDs allowed in the supplemental group access list. -
.maxgroups=
: Sets the maximum number of group IDs allowed in the supplemental group access list. -
.setpgid
: Sets the process group ID of a process. -
.setpriority
: Sets the scheduling priority for a process, process group, or user.
Timing
-
.clock_getres
: Returns the resolution of a system clock. -
.clock_gettime
: Returns the time from a system clock. -
.times
: Returns a::Process::Tms
object containing times for the current process and its child processes.
# File 'process.c', line 8721
static VALUE get_CHILD_STATUS(ID _x, VALUE *_y) { return rb_last_status_get(); }