Class: Process::Status

Inherits:

Object

Object
Process::Status

show all

Defined in:: process.c

Overview

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

#&(num) ⇒ Fixnum

Logical AND of the bits in stat with num.
#==(other) ⇒ Boolean

Returns true if the integer value of stat equals other.
#>>(num) ⇒ Fixnum

Shift the bits in stat right num places.
#coredump? ⇒ Boolean

Returns true if stat generated a coredump when it terminated.
#exited? ⇒ Boolean

Returns true if stat exited normally (for example using an exit() call or finishing the program).
#exitstatus ⇒ Fixnum^?

Returns the least significant eight bits of the return code of stat.
#inspect ⇒ String

Override the inspection method.
#pid ⇒ Fixnum

Returns the process ID that this status object represents.
#signaled? ⇒ Boolean

Returns true if stat terminated because of an uncaught signal.
#stopped? ⇒ Boolean

Returns true if this process is stopped.
#stopsig ⇒ Fixnum^?

Returns the number of the signal that caused stat to stop (or nil if self is not stopped).
#success? ⇒ true, ...

Returns true if stat is successful, false if not.
#termsig ⇒ Fixnum^?

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

Returns the bits in stat as a Fixnum.
#to_s ⇒ String

Show pid and exit status as a string.

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:

(Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     stat & num   -> fixnum
 *
 *  Logical AND of the bits in _stat_ with <em>num</em>.
 *
 *     fork { exit 0x37 }
 *     Process.wait
 *     sprintf('%04x', $?.to_i)       #=> "3700"
 *     sprintf('%04x', $? & 0x1e00)   #=> "1600"
 */

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)

# File 'process.c'

/*
 *  call-seq:
 *     stat == other   -> true or false
 *
 *  Returns +true+ if the integer value of _stat_
 *  equals <em>other</em>.
 */

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:

(Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     stat >> num   -> fixnum
 *
 *  Shift the bits in _stat_ right <em>num</em> places.
 *
 *     fork { exit 99 }   #=> 26563
 *     Process.wait       #=> 26563
 *     $?.to_i            #=> 25344
 *     $? >> 8            #=> 99
 */

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)

# File 'process.c'

/*
 *  call-seq:
 *     stat.coredump?   -> true or false
 *
 *  Returns +true+ if _stat_ generated a coredump
 *  when it terminated. Not available on all platforms.
 */

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)

# File 'process.c'

/*
 *  call-seq:
 *     stat.exited?   -> true or false
 *
 *  Returns +true+ if _stat_ exited normally (for
 *  example using an <code>exit()</code> call or finishing the
 *  program).
 */

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:

(Fixnum, nil)

# File 'process.c'

/*
 *  call-seq:
 *     stat.exitstatus   -> fixnum or nil
 *
 *  Returns the least significant eight bits of the return code of
 *  _stat_. Only available if <code>exited?</code> is
 *  +true+.
 *
 *     fork { }           #=> 26572
 *     Process.wait       #=> 26572
 *     $?.exited?         #=> true
 *     $?.exitstatus      #=> 0
 *
 *     fork { exit 99 }   #=> 26573
 *     Process.wait       #=> 26573
 *     $?.exited?         #=> true
 *     $?.exitstatus      #=> 99
 */

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.

Returns:

(String)

# File 'process.c'

/*
 *  call-seq:
 *     stat.inspect   -> string
 *
 *  Override the inspection method.
 */

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:

(Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     stat.pid   -> fixnum
 *
 *  Returns the process ID that this status object represents.
 *
 *     fork { exit }   #=> 26569
 *     Process.wait    #=> 26569
 *     $?.pid          #=> 26569
 */

static VALUE
pst_pid(VALUE st)
{
    return rb_attr_get(st, rb_intern("pid"));
}

#signaled? ⇒ `Boolean`

Returns true if stat terminated because of an uncaught signal.

Returns:

(Boolean)

# File 'process.c'

/*
 *  call-seq:
 *     stat.signaled?   -> true or false
 *
 *  Returns +true+ if _stat_ terminated because of
 *  an uncaught signal.
 */

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)

# File 'process.c'

/*
 *  call-seq:
 *     stat.stopped?   -> true or false
 *
 *  Returns +true+ if this process is stopped. This is only
 *  returned if the corresponding <code>wait</code> call had the
 *  <code>WUNTRACED</code> flag set.
 */

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:

(Fixnum, nil)

# File 'process.c'

/*
 *  call-seq:
 *     stat.stopsig   -> fixnum or nil
 *
 *  Returns the number of the signal that caused _stat_ to stop
 *  (or +nil+ if self is not stopped).
 */

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)

# File 'process.c'

/*
 *  call-seq:
 *     stat.success?   -> true, false or nil
 *
 *  Returns +true+ if _stat_ is successful, +false+ if not.
 *  Returns +nil+ if <code>exited?</code> is not +true+.
 */

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:

(Fixnum, nil)

# File 'process.c'

/*
 *  call-seq:
 *     stat.termsig   -> fixnum or nil
 *
 *  Returns the number of the signal that caused _stat_ to
 *  terminate (or +nil+ if self was not terminated by an
 *  uncaught signal).
 */

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:

#to_i ⇒ Fixnum
Returns:
- (Fixnum)
#to_int ⇒ Fixnum
Returns:
- (Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     stat.to_i     -> fixnum
 *     stat.to_int   -> fixnum
 *
 *  Returns the bits in _stat_ as a <code>Fixnum</code>. Poking
 *  around in these bits is platform dependent.
 *
 *     fork { exit 0xab }         #=> 26566
 *     Process.wait               #=> 26566
 *     sprintf('%04x', $?.to_i)   #=> "ab00"
 */

static VALUE
pst_to_i(VALUE st)
{
    return rb_iv_get(st, "status");
}

#to_s ⇒ `String`

Show pid and exit status as a string.

Returns:

(String)

# File 'process.c'

/*
 *  call-seq:
 *     stat.to_s   -> string
 *
 *  Show pid and exit status as a string.
 */

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;
}

Class: Process::Status

Overview

Instance Method Summary collapse

Instance Method Details

#&(num) ⇒ Fixnum

#==(other) ⇒ Boolean

#>>(num) ⇒ Fixnum

#coredump? ⇒ Boolean

#exited? ⇒ Boolean

#exitstatus ⇒ Fixnum?

#inspect ⇒ String

#pid ⇒ Fixnum

#signaled? ⇒ Boolean

#stopped? ⇒ Boolean

#stopsig ⇒ Fixnum?

#success? ⇒ true, ...

#termsig ⇒ Fixnum?

#to_i ⇒ Fixnum #to_int ⇒ Fixnum

#to_s ⇒ String

#&(num) ⇒ `Fixnum`

#==(other) ⇒ `Boolean`

#>>(num) ⇒ `Fixnum`

#coredump? ⇒ `Boolean`

#exited? ⇒ `Boolean`

#exitstatus ⇒ `Fixnum`^?

#inspect ⇒ `String`

#pid ⇒ `Fixnum`

#signaled? ⇒ `Boolean`

#stopped? ⇒ `Boolean`

#stopsig ⇒ `Fixnum`^?

#success? ⇒ `true`, ...

#termsig ⇒ `Fixnum`^?

#to_i ⇒ `Fixnum` #to_int ⇒ `Fixnum`

#to_s ⇒ `String`