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Exception: SystemCallError

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: StandardError
Defined in: error.c,
error.c

Overview

SystemCallError is the base class for all low-level platform-dependent errors.

The errors available on the current platform are subclasses of SystemCallError and are defined in the ::Errno module.

File.open("does/not/exist")

raises the exception:

Errno::ENOENT: No such file or directory - does/not/exist

Class Attribute Summary

::Exception - Inherited

.to_tty?

Returns true if exception messages will be sent to a tty.

Class Method Summary

::Exception - Inherited

.exception

With no argument, or if the argument is the same as the receiver, return the receiver.

.new

Construct a new ::Exception object, optionally passing in a message.

Instance Method Summary

::Exception - Inherited

#==

Equality—If obj is not an ::Exception, returns false.

#backtrace

Returns any backtrace associated with the exception.

#backtrace_locations

Returns any backtrace associated with the exception.

#cause

Returns the previous exception ($!) at the time this exception was raised.

#exception

With no argument, or if the argument is the same as the receiver, return the receiver.

#full_message

Returns formatted string of exception.

#inspect

Return this exception's class name and message.

#message

Returns the result of invoking exception.to_s.

#set_backtrace

Sets the backtrace information associated with exc.

#to_s

Returns exception's message (or the name of the exception if no message is set).

Constructor Details

.new(msg, errno) ⇒ system_call_error_subclass

If errno corresponds to a known system error code, constructs the appropriate ::Errno class for that error, otherwise constructs a generic SystemCallError object. The error number is subsequently available via the #errno method.

[ GitHub ]

  
# File 'error.c', line 1969

static VALUE
syserr_initialize(int argc, VALUE *argv, VALUE self)
{
#if !defined(_WIN32)
    char *strerror();
#endif
    const char *err;
    VALUE mesg, error, func, errmsg;
    VALUE klass = rb_obj_class(self);

    if (klass == rb_eSystemCallError) {
	st_data_t data = (st_data_t)klass;
	rb_scan_args(argc, argv, "12", &mesg, &error, &func);
	if (argc == 1 && FIXNUM_P(mesg)) {
	    error = mesg; mesg = Qnil;
	}
	if (!NIL_P(error) && st_lookup(syserr_tbl, NUM2LONG(error), &data)) {
	    klass = (VALUE)data;
	    /* change class */
	    if (!RB_TYPE_P(self, T_OBJECT)) { /* insurance to avoid type crash */
		rb_raise(rb_eTypeError, "invalid instance type");
	    }
	    RBASIC_SET_CLASS(self, klass);
	}
    }
    else {
	rb_scan_args(argc, argv, "02", &mesg, &func);
	error = rb_const_get(klass, id_Errno);
    }
    if (!NIL_P(error)) err = strerror(NUM2INT(error));
    else err = "unknown error";

    errmsg = rb_enc_str_new_cstr(err, rb_locale_encoding());
    if (!NIL_P(mesg)) {
	VALUE str = StringValue(mesg);

	if (!NIL_P(func)) rb_str_catf(errmsg, " @ %"PRIsVALUE, func);
	rb_str_catf(errmsg, " - %"PRIsVALUE, str);
	OBJ_INFECT(errmsg, mesg);
    }
    mesg = errmsg;

    rb_call_super(1, &mesg);
    rb_ivar_set(self, id_errno, error);
    return self;
}

Class Method Details

.===(other) ⇒ Boolean

Return true if the receiver is a generic SystemCallError, or if the error numbers self and other are the same.

[ GitHub ]

  
# File 'error.c', line 2037

static VALUE
syserr_eqq(VALUE self, VALUE exc)
{
    VALUE num, e;

    if (!rb_obj_is_kind_of(exc, rb_eSystemCallError)) {
	if (!rb_respond_to(exc, id_errno)) return Qfalse;
    }
    else if (self == rb_eSystemCallError) return Qtrue;

    num = rb_attr_get(exc, id_errno);
    if (NIL_P(num)) {
	num = rb_funcallv(exc, id_errno, 0, 0);
    }
    e = rb_const_get(self, id_Errno);
    if (FIXNUM_P(num) ? num == e : rb_equal(num, e))
	return Qtrue;
    return Qfalse;
}

Instance Method Details

#errnoInteger

Return this SystemCallError's error number.

[ GitHub ]

  
# File 'error.c', line 2023

static VALUE
syserr_errno(VALUE self)
{
    return rb_attr_get(self, id_errno);
}