Class SystemCallError
In: error.c
Parent: StandardError

Descendents of class Exception are used to communicate between raise methods and rescue statements in begin/end blocks. Exception objects carry information about the exception—its type (the exception‘s class name), an optional descriptive string, and optional traceback information. Programs may subclass Exception to add additional information.

Methods

===   errno   new  

Public Class methods

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

[Source]

/*
 * call-seq:
 *   system_call_error === other  => true or false
 *
 * Return +true+ if the receiver is a generic +SystemCallError+, or
 * if the error numbers _self_ and _other_ are the same.
 */


static VALUE
syserr_eqq(self, exc)
    VALUE self, exc;
{
    VALUE num, e;
    ID en = rb_intern("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, en);
    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;
}

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.

[Source]

/*
 * call-seq:
 *   SystemCallError.new(msg, errno)  => system_call_error_subclass
 *
 * If _errno_ corresponds to a known system error code, constructs
 * the appropriate <code>Errno</code> class for that error, otherwise
 * constructs a generic <code>SystemCallError</code> object. The
 * error number is subsequently available via the <code>errno</code>
 * method.
 */

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

    if (klass == rb_eSystemCallError) {
        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), &klass)) {
            /* change class */
            if (TYPE(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(NUM2LONG(error));
    else err = "unknown error";
    if (!NIL_P(mesg)) {
        VALUE str = mesg;
        size_t len;

        StringValue(str);
        len = strlen(err)+RSTRING(str)->len+3;
        mesg = rb_str_new(0, len);
        snprintf(RSTRING(mesg)->ptr, len+1, "%s - %.*s", err,
                (int)RSTRING(str)->len, RSTRING(str)->ptr);
        rb_str_resize(mesg, strlen(RSTRING(mesg)->ptr));
    }
    else {
        mesg = rb_str_new2(err);
    }
    rb_call_super(1, &mesg);
    rb_iv_set(self, "errno", error);
    return self;
}

Public Instance methods

Return this SystemCallError‘s error number.

[Source]

/*
 * call-seq:
 *   system_call_error.errno   => fixnum
 *
 * Return this SystemCallError's error number.
 */

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

[Validate]