class Process::Status

A Process::Status contains information about a system process.

Thread-local variable $? is initially nil. Some methods assign to it a Process::Status object that represents a system process (either running or terminated):

`ruby -e "exit 99"`
stat = $?       # => #<Process::Status: pid 1262862 exit 99>
stat.class      # => Process::Status
stat.to_i       # => 25344
stat.stopped?   # => false
stat.exited?    # => true
stat.exitstatus # => 99

Public Class Methods

Process::Status.wait(pid = -1, flags = 0) → Process::Status

Like Process.wait, but returns a Process::Status object (instead of an integer pid or nil); see Process.wait for the values of pid and flags.

If there are child processes, waits for a child process to exit and returns a Process::Status object containing information on that process; sets thread-local variable $?:

Process.spawn('cat /nop') # => 1155880
Process::Status.wait      # => #<Process::Status: pid 1155880 exit 1>
$?                        # => #<Process::Status: pid 1155508 exit 1>

If there is no child process, returns an “empty” Process::Status object that does not represent an actual process; does not set thread-local variable $?:

Process::Status.wait # => #<Process::Status: pid -1 exit 0>
$?                   # => #<Process::Status: pid 1155508 exit 1> # Unchanged.

May invoke the scheduler hook Fiber::Scheduler#process_wait.

Not available on all platforms.

static VALUE
rb_process_status_waitv(int argc, VALUE *argv, VALUE _)
{
    rb_check_arity(argc, 0, 2);

    rb_pid_t pid = -1;
    int flags = 0;

    if (argc >= 1) {
        pid = NUM2PIDT(argv[0]);
    }

    if (argc >= 2) {
        flags = RB_NUM2INT(argv[1]);
    }

    return rb_process_status_wait(pid, flags);
}

Public Instance Methods

stat & mask → integer

This method is deprecated as to_i value is system-specific; use predicate methods like exited? or stopped?, or getters like exitstatus or stopsig.

Returns the logical AND of the value of to_i with mask:

`cat /nop`
stat = $?                 # => #<Process::Status: pid 1155508 exit 1>
sprintf('%x', stat.to_i)  # => "100"
stat & 0x00               # => 0

ArgumentError is raised if mask is negative.

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

    if (mask < 0) {
        rb_raise(rb_eArgError, "negative mask value: %d", mask);
    }
#define WARN_SUGGEST(suggest) \
    rb_warn_deprecated_to_remove_at(3.5, "Process::Status#&", suggest)

    switch (mask) {
      case 0x80:
        WARN_SUGGEST("Process::Status#coredump?");
        break;
      case 0x7f:
        WARN_SUGGEST("Process::Status#signaled? or Process::Status#termsig");
        break;
      case 0xff:
        WARN_SUGGEST("Process::Status#exited?, Process::Status#stopped? or Process::Status#coredump?");
        break;
      case 0xff00:
        WARN_SUGGEST("Process::Status#exitstatus or Process::Status#stopsig");
        break;
      default:
        WARN_SUGGEST("other Process::Status predicates");
        break;
    }
#undef WARN_SUGGEST
    status &= mask;

    return INT2NUM(status);
}

stat == other → true or false

Returns whether the value of to_i == other:

`cat /nop`
stat = $?                # => #<Process::Status: pid 1170366 exit 1>
sprintf('%x', stat.to_i) # => "100"
stat == 0x100            # => true

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

stat >> places → integer

This method is deprecated as to_i value is system-specific; use predicate methods like exited? or stopped?, or getters like exitstatus or stopsig.

Returns the value of to_i, shifted places to the right:

`cat /nop`
stat = $?                 # => #<Process::Status: pid 1155508 exit 1>
stat.to_i                 # => 256
stat >> 1                 # => 128
stat >> 2                 # => 64

ArgumentError is raised if places is negative.

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

    if (places < 0) {
        rb_raise(rb_eArgError, "negative shift value: %d", places);
    }
#define WARN_SUGGEST(suggest) \
    rb_warn_deprecated_to_remove_at(3.5, "Process::Status#>>", suggest)

    switch (places) {
      case 7:
        WARN_SUGGEST("Process::Status#coredump?");
        break;
      case 8:
        WARN_SUGGEST("Process::Status#exitstatus or Process::Status#stopsig");
        break;
      default:
        WARN_SUGGEST("other Process::Status attributes");
        break;
    }
#undef WARN_SUGGEST
    status >>= places;

    return INT2NUM(status);
}

coredump? → true or false

Returns true if the process generated a coredump when it terminated, false if not.

Not available on all platforms.

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

    return RBOOL(WCOREDUMP(status));
#else
    return Qfalse;
#endif
}

exited? → true or false

Returns true if the process exited normally (for example using an exit() call or finishing the program), false if not.

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

    return RBOOL(WIFEXITED(status));
}

exitstatus → integer or nil

Returns the least significant eight bits of the return code of the process if it has exited; nil otherwise:

`exit 99`
$?.exitstatus # => 99

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

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

inspect → string

Returns a string representation of self:

system("false")
$?.inspect # => "#<Process::Status: pid 1303494 exit 1>"

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

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

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

pid → integer

Returns the process ID of the process:

system("false")
$?.pid # => 1247002

static VALUE
pst_pid_m(VALUE self)
{
    rb_pid_t pid = pst_pid(self);
    return PIDT2NUM(pid);
}

signaled? → true or false

Returns true if the process terminated because of an uncaught signal, false otherwise.

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

    return RBOOL(WIFSIGNALED(status));
}

stopped? → true or false

Returns true if this process is stopped, and if the corresponding wait call had the Process::WUNTRACED flag set, false otherwise.

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

    return RBOOL(WIFSTOPPED(status));
}

stopsig → integer or nil

Returns the number of the signal that caused the process to stop, or nil if the process is not stopped.

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

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

success? → true, false, or nil

Returns:

true if the process has completed successfully and exited.
false if the process has completed unsuccessfully and exited.
nil if the process has not exited.

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

    if (!WIFEXITED(status))
        return Qnil;
    return RBOOL(WEXITSTATUS(status) == EXIT_SUCCESS);
}

termsig → integer or nil

Returns the number of the signal that caused the process to terminate or nil if the process 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 → integer

Returns the system-dependent integer status of self:

`cat /nop`
$?.to_i # => 256

static VALUE
pst_to_i(VALUE self)
{
    int status = pst_status(self);
    return RB_INT2NUM(status);
}

to_s → string

Returns a string representation of self:

`cat /nop`
$?.to_s # => "pid 1262141 exit 1"

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

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

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