Class: Process::Status

Inherits:
Object show all
Defined in:
process.c,
process.c

Overview

*******************************************************************

<code>Process::Status</code> encapsulates the information on the
status of a running or terminated system process. The built-in
variable <code>$?</code> is either +nil+ or a
<code>Process::Status</code> object.

   fork { exit 99 }   #=> 26557
   Process.wait       #=> 26557
   $?.class           #=> Process::Status
   $?.to_i            #=> 25344
   $? >> 8            #=> 99
   $?.stopped?        #=> false
   $?.exited?         #=> true
   $?.exitstatus      #=> 99

Posix systems record information on processes using a 16-bit
integer.  The lower bits record the process status (stopped,
exited, signaled) and the upper bits possibly contain additional
information (for example the program's return code in the case of
exited processes). Pre Ruby 1.8, these bits were exposed directly
to the Ruby program. Ruby now encapsulates these in a
<code>Process::Status</code> object. To maximize compatibility,
however, these objects retain a bit-oriented interface. In the
descriptions that follow, when we talk about the integer value of
_stat_, we're referring to this 16 bit value.

Instance Method Summary collapse

Instance Method Details

#&(num) ⇒ Fixnum

Logical AND of the bits in stat with num.

fork { exit 0x37 }
Process.wait
sprintf('%04x', $?.to_i)       #=> "3700"
sprintf('%04x', $? & 0x1e00)   #=> "1600"

Returns:



656
657
658
659
660
661
662
 
# File 'process.c', line 656

static VALUE
pst_bitand(VALUE st1, VALUE st2)
{
    int status = PST2INT(st1) & NUM2INT(st2);

    return INT2NUM(status);
}

#==(other) ⇒ Boolean

Returns true if the integer value of stat equals other.

Returns:

  • (Boolean) 


636
637
638
639
640
641
 
# File 'process.c', line 636

static VALUE
pst_equal(VALUE st1, VALUE st2)
{
    if (st1 == st2) return Qtrue;
    return rb_equal(pst_to_i(st1), st2);
}

#>>(num) ⇒ Fixnum

Shift the bits in stat right num places.

fork { exit 99 }   #=> 26563
Process.wait       #=> 26563
$?.to_i            #=> 25344
$? >> 8            #=> 99

Returns:



677
678
679
680
681
682
683
 
# File 'process.c', line 677

static VALUE
pst_rshift(VALUE st1, VALUE st2)
{
    int status = PST2INT(st1) >> NUM2INT(st2);

    return INT2NUM(status);
}

#coredump? ⇒ Boolean

Returns true if stat generated a coredump when it terminated. Not available on all platforms.

Returns:

  • (Boolean)

Returns:

  • (Boolean) 


844
845
846
847
848
849
850
851
852
853
854
855
856
857
 
# File 'process.c', line 844

static VALUE
pst_wcoredump(VALUE st)
{
#ifdef WCOREDUMP
    int status = PST2INT(st);

    if (WCOREDUMP(status))
	return Qtrue;
    else
	return Qfalse;
#else
    return Qfalse;
#endif
}

#exited? ⇒ Boolean

Returns true if stat exited normally (for example using an exit() call or finishing the program).

Returns:

  • (Boolean)

Returns:

  • (Boolean) 


775
776
777
778
779
780
781
782
783
784
 
# File 'process.c', line 775

static VALUE
pst_wifexited(VALUE st)
{
    int status = PST2INT(st);

    if (WIFEXITED(status))
	return Qtrue;
    else
	return Qfalse;
}

#exitstatus ⇒ Fixnum?

Returns the least significant eight bits of the return code of stat. Only available if exited? is true.

fork { }           #=> 26572
Process.wait       #=> 26572
$?.exited?         #=> true
$?.exitstatus      #=> 0

fork { exit 99 }   #=> 26573
Process.wait       #=> 26573
$?.exited?         #=> true
$?.exitstatus      #=> 99

Returns:



806
807
808
809
810
811
812
813
814
 
# File 'process.c', line 806

static VALUE
pst_wexitstatus(VALUE st)
{
    int status = PST2INT(st);

    if (WIFEXITED(status))
	return INT2NUM(WEXITSTATUS(status));
    return Qnil;
}

#inspect ⇒ String

Override the inspection method.

system("false")
p $?.inspect #=> "#<Process::Status: pid 12861 exit 1>"

Returns:



607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
 
# File 'process.c', line 607

static VALUE
pst_inspect(VALUE st)
{
    rb_pid_t pid;
    int status;
    VALUE vpid, str;

    vpid = pst_pid(st);
    if (NIL_P(vpid)) {
        return rb_sprintf("#<%s: uninitialized>", rb_class2name(CLASS_OF(st)));
    }
    pid = NUM2PIDT(vpid);
    status = PST2INT(st);

    str = rb_sprintf("#<%s: ", rb_class2name(CLASS_OF(st)));
    pst_message(str, pid, status);
    rb_str_cat2(str, ">");
    return str;
}

#pid ⇒ Fixnum

Returns the process ID that this status object represents.

fork { exit }   #=> 26569
Process.wait    #=> 26569
$?.pid          #=> 26569

Returns:



528
529
530
531
532
 
# File 'process.c', line 528

static VALUE
pst_pid(VALUE st)
{
    return rb_attr_get(st, id_pid);
}

#signaled? ⇒ Boolean

Returns true if stat terminated because of an uncaught signal.

Returns:

  • (Boolean)

Returns:

  • (Boolean) 


734
735
736
737
738
739
740
741
742
743
 
# File 'process.c', line 734

static VALUE
pst_wifsignaled(VALUE st)
{
    int status = PST2INT(st);

    if (WIFSIGNALED(status))
	return Qtrue;
    else
	return Qfalse;
}

#stopped? ⇒ Boolean

Returns true if this process is stopped. This is only returned if the corresponding wait call had the WUNTRACED flag set.

Returns:

  • (Boolean)

Returns:

  • (Boolean) 


695
696
697
698
699
700
701
702
703
704
 
# File 'process.c', line 695

static VALUE
pst_wifstopped(VALUE st)
{
    int status = PST2INT(st);

    if (WIFSTOPPED(status))
	return Qtrue;
    else
	return Qfalse;
}

#stopsig ⇒ Fixnum?

Returns the number of the signal that caused stat to stop (or nil if self is not stopped).

Returns:



715
716
717
718
719
720
721
722
723
 
# File 'process.c', line 715

static VALUE
pst_wstopsig(VALUE st)
{
    int status = PST2INT(st);

    if (WIFSTOPPED(status))
	return INT2NUM(WSTOPSIG(status));
    return Qnil;
}

#success? ⇒ true, ...

Returns true if stat is successful, false if not. Returns nil if exited? is not true.

Returns:

  • (true, false, nil)

Returns:

  • (Boolean) 


825
826
827
828
829
830
831
832
833
 
# File 'process.c', line 825

static VALUE
pst_success_p(VALUE st)
{
    int status = PST2INT(st);

    if (!WIFEXITED(status))
	return Qnil;
    return WEXITSTATUS(status) == EXIT_SUCCESS ? Qtrue : Qfalse;
}

#termsig ⇒ Fixnum?

Returns the number of the signal that caused stat to terminate (or nil if self was not terminated by an uncaught signal).

Returns:



755
756
757
758
759
760
761
762
763
 
# File 'process.c', line 755

static VALUE
pst_wtermsig(VALUE st)
{
    int status = PST2INT(st);

    if (WIFSIGNALED(status))
	return INT2NUM(WTERMSIG(status));
    return Qnil;
}

#to_i ⇒ Fixnum #to_int ⇒ Fixnum

Returns the bits in stat as a Fixnum. Poking around in these bits is platform dependent.

fork { exit 0xab }         #=> 26566
Process.wait               #=> 26566
sprintf('%04x', $?.to_i)   #=> "ab00"

Overloads:



509
510
511
512
513
 
# File 'process.c', line 509

static VALUE
pst_to_i(VALUE st)
{
    return rb_ivar_get(st, id_status);
}

#to_s ⇒ String

Show pid and exit status as a string.

system("false")
p $?.to_s         #=> "pid 12766 exit 1"

Returns:



580
581
582
583
584
585
586
587
588
589
590
591
592
593
 
# File 'process.c', line 580

static VALUE
pst_to_s(VALUE st)
{
    rb_pid_t pid;
    int status;
    VALUE str;

    pid = NUM2PIDT(pst_pid(st));
    status = PST2INT(st);

    str = rb_str_buf_new(0);
    pst_message(str, pid, status);
    return str;
}