SystemCallError

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

Public Class Methods

system_call_error === other → true or false click to toggle source

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

 
 static VALUE
syserr_eqq(VALUE self, VALUE exc)
{
 VALUE num, e;
 ID en;
 CONST_ID(en, "errno");
 if (!rb_obj_is_kind_of(exc, rb_eSystemCallError)) {
 if (!rb_respond_to(exc, en)) return Qfalse;
 }
 else if (self == rb_eSystemCallError) return Qtrue;
 num = rb_attr_get(exc, rb_intern("errno"));
 if (NIL_P(num)) {
 num = rb_funcall(exc, en, 0, 0);
 }
 e = rb_const_get(self, rb_intern("Errno"));
 if (FIXNUM_P(num) ? num == e : rb_equal(num, e))
 return Qtrue;
 return Qfalse;
}

new(msg, errno) → system_call_error_subclass click to toggle source

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.

 
 static VALUE
syserr_initialize(int argc, VALUE *argv, VALUE self)
{
#if !defined(_WIN32)
 char *strerror();
#endif
 const char *err;
 VALUE mesg, error;
 VALUE klass = rb_obj_class(self);
 if (klass == rb_eSystemCallError) {
 st_data_t data = (st_data_t)klass;
 rb_scan_args(argc, argv, "11", &mesg, &error);
 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(self)->klass = klass;
 }
 }
 else {
 rb_scan_args(argc, argv, "01", &mesg);
 error = rb_const_get(klass, rb_intern("Errno"));
 }
 if (!NIL_P(error)) err = strerror(NUM2INT(error));
 else err = "unknown error";
 if (!NIL_P(mesg)) {
 rb_encoding *le = rb_locale_encoding();
 VALUE str = StringValue(mesg);
 rb_encoding *me = rb_enc_get(mesg);
 mesg = rb_sprintf("%s - %"PRIsVALUE, err, mesg);
 if (le != me && rb_enc_asciicompat(me)) {
 le = me;
 }/* else assume err is non ASCII string. */
 OBJ_INFECT(mesg, str);
 rb_enc_associate(mesg, le);
 }
 else {
 mesg = rb_str_new2(err);
 rb_enc_associate(mesg, rb_locale_encoding());
 }
 rb_call_super(1, &mesg);
 rb_iv_set(self, "errno", error);
 return self;
}

Public Instance Methods

errno → fixnum click to toggle source

Return this SystemCallError's error number.

 
 static VALUE
syserr_errno(VALUE self)
{
 return rb_attr_get(self, rb_intern("errno"));
}