Module Process
In: process.c

The Process module is a collection of methods used to manipulate processes.

Methods

abort   detach   egid   egid=   euid   euid=   exec   exit   exit!   fork   getpgid   getpgrp   getpriority   getrlimit   gid   gid=   groups   groups=   initgroups   kill   maxgroups   maxgroups=   pid   ppid   setpgid   setpgrp   setpriority   setrlimit   setsid   times   uid   uid=   wait   wait2   waitall   waitpid   waitpid2  

Classes and Modules

Module Process::GID
Module Process::Sys
Module Process::UID
Class Process::Status

Constants

WNOHANG = INT2FIX(WNOHANG)
WNOHANG = INT2FIX(0)
WUNTRACED = INT2FIX(WUNTRACED)
WUNTRACED = INT2FIX(0)
PRIO_PROCESS = INT2FIX(PRIO_PROCESS)
PRIO_PGRP = INT2FIX(PRIO_PGRP)
PRIO_USER = INT2FIX(PRIO_USER)
RLIM_INFINITY = inf
RLIM_SAVED_MAX = v
RLIM_SAVED_CUR = v
RLIMIT_CORE = INT2FIX(RLIMIT_CORE)
RLIMIT_CPU = INT2FIX(RLIMIT_CPU)
RLIMIT_DATA = INT2FIX(RLIMIT_DATA)
RLIMIT_FSIZE = INT2FIX(RLIMIT_FSIZE)
RLIMIT_NOFILE = INT2FIX(RLIMIT_NOFILE)
RLIMIT_STACK = INT2FIX(RLIMIT_STACK)
RLIMIT_AS = INT2FIX(RLIMIT_AS)
RLIMIT_MEMLOCK = INT2FIX(RLIMIT_MEMLOCK)
RLIMIT_NPROC = INT2FIX(RLIMIT_NPROC)
RLIMIT_RSS = INT2FIX(RLIMIT_RSS)
RLIMIT_SBSIZE = INT2FIX(RLIMIT_SBSIZE)

Public Class methods

Terminate execution immediately, effectively by calling Kernel.exit(1). If msg is given, it is written to STDERR prior to terminating.

[Source]

/*
 *  call-seq:
 *     abort
 *     Kernel::abort
 *     Process::abort
 *  
 *  Terminate execution immediately, effectively by calling
 *  <code>Kernel.exit(1)</code>. If _msg_ is given, it is written
 *  to STDERR prior to terminating.
 */

VALUE
rb_f_abort(argc, argv)
    int argc;
    VALUE *argv;
{
    rb_secure(4);
    if (argc == 0) {
	if (!NIL_P(ruby_errinfo)) {
	    error_print();
	}
	rb_exit(EXIT_FAILURE);
    }
    else {
	VALUE mesg;

	rb_scan_args(argc, argv, "1", &mesg);
	StringValue(mesg);
	rb_io_puts(1, &mesg, rb_stderr);
	terminate_process(EXIT_FAILURE, mesg);
    }
    return Qnil;		/* not reached */
}

Some operating systems retain the status of terminated child processes until the parent collects that status (normally using some variant of wait(). If the parent never collects this status, the child stays around as a zombie process. Process::detach prevents this by setting up a separate Ruby thread whose sole job is to reap the status of the process pid when it terminates. Use detach only when you do not intent to explicitly wait for the child to terminate. detach only checks the status periodically (currently once each second).

The waiting thread returns the exit status of the detached process when it terminates, so you can use Thread#join to know the result. If specified pid is not a valid child process ID, the thread returns nil immediately.

In this first example, we don‘t reap the first child process, so it appears as a zombie in the process status display.

   p1 = fork { sleep 0.1 }
   p2 = fork { sleep 0.2 }
   Process.waitpid(p2)
   sleep 2
   system("ps -ho pid,state -p #{p1}")

produces:

   27389 Z

In the next example, Process::detach is used to reap the child automatically.

   p1 = fork { sleep 0.1 }
   p2 = fork { sleep 0.2 }
   Process.detach(p1)
   Process.waitpid(p2)
   sleep 2
   system("ps -ho pid,state -p #{p1}")

(produces no output)

[Source]

/*
 *  call-seq:
 *     Process.detach(pid)   => thread
 *
 *  Some operating systems retain the status of terminated child
 *  processes until the parent collects that status (normally using
 *  some variant of <code>wait()</code>. If the parent never collects
 *  this status, the child stays around as a <em>zombie</em> process.
 *  <code>Process::detach</code> prevents this by setting up a
 *  separate Ruby thread whose sole job is to reap the status of the
 *  process _pid_ when it terminates. Use <code>detach</code>
 *  only when you do not intent to explicitly wait for the child to
 *  terminate.  <code>detach</code> only checks the status
 *  periodically (currently once each second).
 *
 *  The waiting thread returns the exit status of the detached process
 *  when it terminates, so you can use <code>Thread#join</code> to
 *  know the result.  If specified _pid_ is not a valid child process
 *  ID, the thread returns +nil+ immediately.
 *
 *  In this first example, we don't reap the first child process, so
 *  it appears as a zombie in the process status display.
 *
 *     p1 = fork { sleep 0.1 }
 *     p2 = fork { sleep 0.2 }
 *     Process.waitpid(p2)
 *     sleep 2
 *     system("ps -ho pid,state -p #{p1}")
 *
 *  <em>produces:</em>
 *
 *     27389 Z
 *
 *  In the next example, <code>Process::detach</code> is used to reap
 *  the child automatically.
 *
 *     p1 = fork { sleep 0.1 }
 *     p2 = fork { sleep 0.2 }
 *     Process.detach(p1)
 *     Process.waitpid(p2)
 *     sleep 2
 *     system("ps -ho pid,state -p #{p1}")
 *
 *  <em>(produces no output)</em>
 */

static VALUE
proc_detach(VALUE obj, VALUE pid)
{
    rb_secure(2);
    return rb_detach_process(NUM2INT(pid));
}

Returns the effective group ID for this process. Not available on all platforms.

   Process.egid   #=> 500

[Source]

/*
 *  call-seq:
 *     Process.egid          => fixnum
 *     Process::GID.eid      => fixnum
 *     Process::Sys.geteid   => fixnum
 *
 *  Returns the effective group ID for this process. Not available on
 *  all platforms.
 *
 *     Process.egid   #=> 500
 */

static VALUE
proc_getegid(obj)
    VALUE obj;
{
    int egid = getegid();

    return INT2FIX(egid);
}

Sets the effective group ID for this process. Not available on all platforms.

[Source]

/*
 *  call-seq:
 *     Process.egid = fixnum   => fixnum
 *
 *  Sets the effective group ID for this process. Not available on all
 *  platforms.
 */

static VALUE
proc_setegid(obj, egid)
    VALUE obj, egid;
{
    check_gid_switch();

#if defined(HAVE_SETRESGID) && !defined(__CHECKER__)
    if (setresgid(-1, NUM2INT(egid), -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETREGID
    if (setregid(-1, NUM2INT(egid)) < 0) rb_sys_fail(0);
#elif defined HAVE_SETEGID
    if (setegid(NUM2INT(egid)) < 0) rb_sys_fail(0);
#elif defined HAVE_SETGID
    egid = NUM2INT(egid);
    if (egid == getgid()) {
        if (setgid(egid) < 0) rb_sys_fail(0);
    }
    else {
        rb_notimplement();
    }
#else
    rb_notimplement();
#endif
    return egid;
}

Returns the effective user ID for this process.

   Process.euid   #=> 501

[Source]

/*
 *  call-seq:
 *     Process.euid           => fixnum
 *     Process::UID.eid       => fixnum
 *     Process::Sys.geteuid   => fixnum
 *
 *  Returns the effective user ID for this process.
 *
 *     Process.euid   #=> 501
 */

static VALUE
proc_geteuid(obj)
    VALUE obj;
{
    int euid = geteuid();
    return INT2FIX(euid);
}

Sets the effective user ID for this process. Not available on all platforms.

[Source]

/*
 *  call-seq:
 *     Process.euid= integer
 *
 *  Sets the effective user ID for this process. Not available on all
 *  platforms.
 */

static VALUE
proc_seteuid(obj, euid)
    VALUE obj, euid;
{
    check_uid_switch();
#if defined(HAVE_SETRESUID) && !defined(__CHECKER__)
    if (setresuid(-1, NUM2INT(euid), -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETREUID
    if (setreuid(-1, NUM2INT(euid)) < 0) rb_sys_fail(0);
#elif defined HAVE_SETEUID
    if (seteuid(NUM2INT(euid)) < 0) rb_sys_fail(0);
#elif defined HAVE_SETUID
    euid = NUM2INT(euid);
    if (euid == getuid()) {
        if (setuid(euid) < 0) rb_sys_fail(0);
    }
    else {
        rb_notimplement();
    }
#else
    rb_notimplement();
#endif
    return euid;
}

Replaces the current process by running the given external command. If exec is given a single argument, that argument is taken as a line that is subject to shell expansion before being executed. If multiple arguments are given, the second and subsequent arguments are passed as parameters to command with no shell expansion. If the first argument is a two-element array, the first element is the command to be executed, and the second argument is used as the argv[0] value, which may show up in process listings. In MSDOS environments, the command is executed in a subshell; otherwise, one of the exec(2) system calls is used, so the running command may inherit some of the environment of the original program (including open file descriptors).

   exec "echo *"       # echoes list of files in current directory
   # never get here

   exec "echo", "*"    # echoes an asterisk
   # never get here

[Source]

/*
 *  call-seq:
 *     exec(command [, arg, ...])
 *
 *  Replaces the current process by running the given external _command_.
 *  If +exec+ is given a single argument, that argument is
 *  taken as a line that is subject to shell expansion before being
 *  executed. If multiple arguments are given, the second and subsequent
 *  arguments are passed as parameters to _command_ with no shell
 *  expansion. If the first argument is a two-element array, the first
 *  element is the command to be executed, and the second argument is
 *  used as the <code>argv[0]</code> value, which may show up in process
 *  listings. In MSDOS environments, the command is executed in a
 *  subshell; otherwise, one of the <code>exec(2)</code> system calls is
 *  used, so the running command may inherit some of the environment of
 *  the original program (including open file descriptors).
 *
 *     exec "echo *"       # echoes list of files in current directory
 *     # never get here
 *
 *
 *     exec "echo", "*"    # echoes an asterisk
 *     # never get here
 */

VALUE
rb_f_exec(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE prog = 0;
    VALUE tmp;
    struct rb_exec_arg earg;

    if (argc == 0) {
        rb_last_status = Qnil;
        rb_raise(rb_eArgError, "wrong number of arguments");
    }

    tmp = rb_check_array_type(argv[0]);
    if (!NIL_P(tmp)) {
        if (RARRAY(tmp)->len != 2) {
            rb_raise(rb_eArgError, "wrong first argument");
        }
        prog = RARRAY(tmp)->ptr[0];
        argv[0] = RARRAY(tmp)->ptr[1];
        SafeStringValue(prog);
    }
    proc_prepare_args(&earg, argc, argv, prog);
    proc_exec_args((VALUE)&earg);
    rb_sys_fail(RSTRING(argv[0])->ptr);
    return Qnil;                /* dummy */
}

Initiates the termination of the Ruby script by raising the SystemExit exception. This exception may be caught. The optional parameter is used to return a status code to the invoking environment.

   begin
     exit
     puts "never get here"
   rescue SystemExit
     puts "rescued a SystemExit exception"
   end
   puts "after begin block"

produces:

   rescued a SystemExit exception
   after begin block

Just prior to termination, Ruby executes any at_exit functions (see Kernel::at_exit) and runs any object finalizers (see ObjectSpace::define_finalizer).

   at_exit { puts "at_exit function" }
   ObjectSpace.define_finalizer("string",  proc { puts "in finalizer" })
   exit

produces:

   at_exit function
   in finalizer

[Source]

/*
 *  call-seq:
 *     exit(integer=0)
 *     Kernel::exit(integer=0)
 *     Process::exit(integer=0)
 *  
 *  Initiates the termination of the Ruby script by raising the
 *  <code>SystemExit</code> exception. This exception may be caught. The
 *  optional parameter is used to return a status code to the invoking
 *  environment.
 *     
 *     begin
 *       exit
 *       puts "never get here"
 *     rescue SystemExit
 *       puts "rescued a SystemExit exception"
 *     end
 *     puts "after begin block"
 *     
 *  <em>produces:</em>
 *     
 *     rescued a SystemExit exception
 *     after begin block
 *     
 *  Just prior to termination, Ruby executes any <code>at_exit</code> functions
 *  (see Kernel::at_exit) and runs any object finalizers (see
 *  ObjectSpace::define_finalizer).
 *     
 *     at_exit { puts "at_exit function" }
 *     ObjectSpace.define_finalizer("string",  proc { puts "in finalizer" })
 *     exit
 *     
 *  <em>produces:</em>
 *     
 *     at_exit function
 *     in finalizer
 */

VALUE
rb_f_exit(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE status;
    int istatus;

    rb_secure(4);
    if (rb_scan_args(argc, argv, "01", &status) == 1) {
	switch (status) {
	  case Qtrue:
	    istatus = EXIT_SUCCESS;
	    break;
	  case Qfalse:
	    istatus = EXIT_FAILURE;
	    break;
	  default:
	    istatus = NUM2INT(status);
#if EXIT_SUCCESS != 0
	    if (istatus == 0) istatus = EXIT_SUCCESS;
#endif
	    break;
	}
    }
    else {
	istatus = EXIT_SUCCESS;
    }
    rb_exit(istatus);
    return Qnil;		/* not reached */
}

Exits the process immediately. No exit handlers are run. fixnum is returned to the underlying system as the exit status.

   Process.exit!(0)

[Source]

/*
 *  call-seq:
 *     Process.exit!(fixnum=-1)
 *
 *  Exits the process immediately. No exit handlers are
 *  run. <em>fixnum</em> is returned to the underlying system as the
 *  exit status.
 *
 *     Process.exit!(0)
 */

static VALUE
rb_f_exit_bang(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    VALUE status;
    int istatus;

    rb_secure(4);
    if (rb_scan_args(argc, argv, "01", &status) == 1) {
        switch (status) {
          case Qtrue:
            istatus = EXIT_SUCCESS;
            break;
          case Qfalse:
            istatus = EXIT_FAILURE;
            break;
          default:
            istatus = NUM2INT(status);
            break;
        }
    }
    else {
        istatus = EXIT_FAILURE;
    }
    _exit(istatus);

    return Qnil;                /* not reached */
}

Creates a subprocess. If a block is specified, that block is run in the subprocess, and the subprocess terminates with a status of zero. Otherwise, the fork call returns twice, once in the parent, returning the process ID of the child, and once in the child, returning nil. The child process can exit using Kernel.exit! to avoid running any at_exit functions. The parent process should use Process.wait to collect the termination statuses of its children or use Process.detach to register disinterest in their status; otherwise, the operating system may accumulate zombie processes.

The thread calling fork is the only thread in the created child process. fork doesn‘t copy other threads.

[Source]

/*
 *  call-seq:
 *     Kernel.fork  [{ block }]   => fixnum or nil
 *     Process.fork [{ block }]   => fixnum or nil
 *
 *  Creates a subprocess. If a block is specified, that block is run
 *  in the subprocess, and the subprocess terminates with a status of
 *  zero. Otherwise, the +fork+ call returns twice, once in
 *  the parent, returning the process ID of the child, and once in
 *  the child, returning _nil_. The child process can exit using
 *  <code>Kernel.exit!</code> to avoid running any
 *  <code>at_exit</code> functions. The parent process should
 *  use <code>Process.wait</code> to collect the termination statuses
 *  of its children or use <code>Process.detach</code> to register
 *  disinterest in their status; otherwise, the operating system
 *  may accumulate zombie processes.
 *
 *  The thread calling fork is the only thread in the created child process.
 *  fork doesn't copy other threads.
 */

static VALUE
rb_f_fork(obj)
    VALUE obj;
{
#if !defined(__human68k__) && !defined(_WIN32) && !defined(__MACOS__) && !defined(__EMX__) && !defined(__VMS)
    int pid;

    rb_secure(2);

#ifndef __VMS
    fflush(stdout);
    fflush(stderr);
#endif

    switch (pid = fork()) {
      case 0:
#ifdef linux
        after_exec();
#endif
        rb_thread_atfork();
        if (rb_block_given_p()) {
            int status;

            rb_protect(rb_yield, Qundef, &status);
            ruby_stop(status);
        }
        return Qnil;

      case -1:
        rb_sys_fail("fork(2)");
        return Qnil;

      default:
        return INT2FIX(pid);
    }
#else
    rb_notimplement();
#endif
}

Returns the process group ID for the given process id. Not available on all platforms.

   Process.getpgid(Process.ppid())   #=> 25527

[Source]

/*
 *  call-seq:
 *     Process.getpgid(pid)   => integer
 *
 *  Returns the process group ID for the given process id. Not
 *  available on all platforms.
 *
 *     Process.getpgid(Process.ppid())   #=> 25527
 */

static VALUE
proc_getpgid(obj, pid)
    VALUE obj, pid;
{
#if defined(HAVE_GETPGID) && !defined(__CHECKER__)
    int i;

    rb_secure(2);
    i = getpgid(NUM2INT(pid));
    if (i < 0) rb_sys_fail(0);
    return INT2NUM(i);
#else
    rb_notimplement();
#endif
}

Returns the process group ID for this process. Not available on all platforms.

   Process.getpgid(0)   #=> 25527
   Process.getpgrp      #=> 25527

[Source]

/*
 *  call-seq:
 *     Process.getpgrp   => integer
 *
 *  Returns the process group ID for this process. Not available on
 *  all platforms.
 *
 *     Process.getpgid(0)   #=> 25527
 *     Process.getpgrp      #=> 25527
 */

static VALUE
proc_getpgrp()
{
#if defined(HAVE_GETPGRP) && defined(GETPGRP_VOID)
    int pgrp;
#endif

    rb_secure(2);
#if defined(HAVE_GETPGRP) && defined(GETPGRP_VOID)
    pgrp = getpgrp();
    if (pgrp < 0) rb_sys_fail(0);
    return INT2FIX(pgrp);
#else
# ifdef HAVE_GETPGID
    pgrp = getpgid(0);
    if (pgrp < 0) rb_sys_fail(0);
    return INT2FIX(pgrp);
# else
    rb_notimplement();
# endif
#endif
}

Gets the scheduling priority for specified process, process group, or user. kind indicates the kind of entity to find: one of Process::PRIO_PGRP, Process::PRIO_USER, or Process::PRIO_PROCESS. integer is an id indicating the particular process, process group, or user (an id of 0 means current). Lower priorities are more favorable for scheduling. Not available on all platforms.

   Process.getpriority(Process::PRIO_USER, 0)      #=> 19
   Process.getpriority(Process::PRIO_PROCESS, 0)   #=> 19

[Source]

/*
 *  call-seq:
 *     Process.getpriority(kind, integer)   => fixnum
 *
 *  Gets the scheduling priority for specified process, process group,
 *  or user. <em>kind</em> indicates the kind of entity to find: one
 *  of <code>Process::PRIO_PGRP</code>,
 *  <code>Process::PRIO_USER</code>, or
 *  <code>Process::PRIO_PROCESS</code>. _integer_ is an id
 *  indicating the particular process, process group, or user (an id
 *  of 0 means _current_). Lower priorities are more favorable
 *  for scheduling. Not available on all platforms.
 *
 *     Process.getpriority(Process::PRIO_USER, 0)      #=> 19
 *     Process.getpriority(Process::PRIO_PROCESS, 0)   #=> 19
 */

static VALUE
proc_getpriority(obj, which, who)
    VALUE obj, which, who;
{
#ifdef HAVE_GETPRIORITY
    int prio, iwhich, iwho;

    rb_secure(2);
    iwhich = NUM2INT(which);
    iwho   = NUM2INT(who);

    errno = 0;
    prio = getpriority(iwhich, iwho);
    if (errno) rb_sys_fail(0);
    return INT2FIX(prio);
#else
    rb_notimplement();
#endif
}

Gets the resource limit of the process. cur_limit means current (soft) limit and max_limit means maximum (hard) limit.

resource indicates the kind of resource to limit: such as Process::RLIMIT_CORE, Process::RLIMIT_CPU, etc. See Process.setrlimit for details.

cur_limit and max_limit may be Process::RLIM_INFINITY, Process::RLIM_SAVED_MAX or Process::RLIM_SAVED_CUR. See Process.setrlimit and the system getrlimit(2) manual for details.

[Source]

/*
 *  call-seq:
 *     Process.getrlimit(resource)   => [cur_limit, max_limit]
 *
 *  Gets the resource limit of the process.
 *  _cur_limit_ means current (soft) limit and
 *  _max_limit_ means maximum (hard) limit.
 *
 *  _resource_ indicates the kind of resource to limit:
 *  such as <code>Process::RLIMIT_CORE</code>,
 *  <code>Process::RLIMIT_CPU</code>, etc.
 *  See Process.setrlimit for details.
 *
 *  _cur_limit_ and _max_limit_ may be <code>Process::RLIM_INFINITY</code>,
 *  <code>Process::RLIM_SAVED_MAX</code> or
 *  <code>Process::RLIM_SAVED_CUR</code>.
 *  See Process.setrlimit and the system getrlimit(2) manual for details.
 */

static VALUE
proc_getrlimit(VALUE obj, VALUE resource)
{
#if defined(HAVE_GETRLIMIT) && defined(RLIM2NUM)
    struct rlimit rlim;

    rb_secure(2);

    if (getrlimit(NUM2INT(resource), &rlim) < 0) {
        rb_sys_fail("getrlimit");
    }
    return rb_assoc_new(RLIM2NUM(rlim.rlim_cur), RLIM2NUM(rlim.rlim_max));
#else
    rb_notimplement();
#endif
}

Returns the (real) group ID for this process.

   Process.gid   #=> 500

[Source]

/*
 *  call-seq:
 *     Process.gid           => fixnum
 *     Process::GID.rid      => fixnum
 *     Process::Sys.getgid   => fixnum
 *
 *  Returns the (real) group ID for this process.
 *
 *     Process.gid   #=> 500
 */

static VALUE
proc_getgid(obj)
    VALUE obj;
{
    int gid = getgid();
    return INT2FIX(gid);
}

Sets the group ID for this process.

[Source]

/*
 *  call-seq:
 *     Process.gid= fixnum   => fixnum
 *
 *  Sets the group ID for this process.
 */

static VALUE
proc_setgid(obj, id)
    VALUE obj, id;
{
    int gid = NUM2INT(id);

    check_gid_switch();
#if defined(HAVE_SETRESGID) && !defined(__CHECKER__)
    if (setresgid(gid, -1, -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETREGID
    if (setregid(gid, -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETRGID
    if (setrgid(gid) < 0) rb_sys_fail(0);
#elif defined HAVE_SETGID
    {
        if (getegid() == gid) {
            if (setgid(gid) < 0) rb_sys_fail(0);
        }
        else {
            rb_notimplement();
        }
    }
#else
    rb_notimplement();
#endif
    return INT2FIX(gid);
}

Get an Array of the gids of groups in the supplemental group access list for this process.

   Process.groups   #=> [27, 6, 10, 11]

[Source]

/*
 *  call-seq:
 *     Process.groups   => array
 *
 *  Get an <code>Array</code> of the gids of groups in the
 *  supplemental group access list for this process.
 *
 *     Process.groups   #=> [27, 6, 10, 11]
 *
 */

static VALUE
proc_getgroups(VALUE obj)
{
#ifdef HAVE_GETGROUPS
    VALUE ary;
    size_t ngroups;
    rb_gid_t *groups;
    int i;

    groups = ALLOCA_N(rb_gid_t, maxgroups);

    ngroups = getgroups(maxgroups, groups);
    if (ngroups == -1)
        rb_sys_fail(0);

    ary = rb_ary_new();
    for (i = 0; i < ngroups; i++)
        rb_ary_push(ary, INT2NUM(groups[i]));

    return ary;
#else
    rb_notimplement();
    return Qnil;
#endif
}

Set the supplemental group access list to the given Array of group IDs.

   Process.groups   #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27]
   Process.groups = [27, 6, 10, 11]   #=> [27, 6, 10, 11]
   Process.groups   #=> [27, 6, 10, 11]

[Source]

/*
 *  call-seq:
 *     Process.groups= array   => array
 *
 *  Set the supplemental group access list to the given
 *  <code>Array</code> of group IDs.
 *
 *     Process.groups   #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27]
 *     Process.groups = [27, 6, 10, 11]   #=> [27, 6, 10, 11]
 *     Process.groups   #=> [27, 6, 10, 11]
 *
 */

static VALUE
proc_setgroups(VALUE obj, VALUE ary)
{
#ifdef HAVE_SETGROUPS
    size_t ngroups;
    rb_gid_t *groups;
    int i;
    struct group *gr;

    Check_Type(ary, T_ARRAY);

    ngroups = RARRAY(ary)->len;
    if (ngroups > maxgroups)
        rb_raise(rb_eArgError, "too many groups, %d max", maxgroups);

    groups = ALLOCA_N(rb_gid_t, ngroups);

    for (i = 0; i < ngroups && i < RARRAY(ary)->len; i++) {
        VALUE g = RARRAY(ary)->ptr[i];

        if (FIXNUM_P(g)) {
            groups[i] = FIX2INT(g);
        }
        else {
            VALUE tmp = rb_check_string_type(g);

            if (NIL_P(tmp)) {
                groups[i] = NUM2INT(g);
            }
            else {
                gr = getgrnam(RSTRING(tmp)->ptr);
                if (gr == NULL)
                    rb_raise(rb_eArgError,
                             "can't find group for %s", RSTRING(tmp)->ptr);
                groups[i] = gr->gr_gid;
            }
        }
    }

    i = setgroups(ngroups, groups);
    if (i == -1)
        rb_sys_fail(0);

    return proc_getgroups(obj);
#else
    rb_notimplement();
    return Qnil;
#endif
}

Initializes the supplemental group access list by reading the system group database and using all groups of which the given user is a member. The group with the specified gid is also added to the list. Returns the resulting Array of the gids of all the groups in the supplementary group access list. Not available on all platforms.

   Process.groups   #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27]
   Process.initgroups( "mgranger", 30 )   #=> [30, 6, 10, 11]
   Process.groups   #=> [30, 6, 10, 11]

[Source]

/*
 *  call-seq:
 *     Process.initgroups(username, gid)   => array
 *
 *  Initializes the supplemental group access list by reading the
 *  system group database and using all groups of which the given user
 *  is a member. The group with the specified <em>gid</em> is also
 *  added to the list. Returns the resulting <code>Array</code> of the
 *  gids of all the groups in the supplementary group access list. Not
 *  available on all platforms.
 *
 *     Process.groups   #=> [0, 1, 2, 3, 4, 6, 10, 11, 20, 26, 27]
 *     Process.initgroups( "mgranger", 30 )   #=> [30, 6, 10, 11]
 *     Process.groups   #=> [30, 6, 10, 11]
 *
 */

static VALUE
proc_initgroups(obj, uname, base_grp)
    VALUE obj, uname, base_grp;
{
#ifdef HAVE_INITGROUPS
    if (initgroups(StringValuePtr(uname), (rb_gid_t)NUM2INT(base_grp)) != 0) {
        rb_sys_fail(0);
    }
    return proc_getgroups(obj);
#else
    rb_notimplement();
    return Qnil;
#endif
}

Sends the given signal to the specified process id(s), or to the current process if pid is zero. signal may be an integer signal number or a POSIX signal name (either with or without a SIG prefix). If signal is negative (or starts with a minus sign), kills process groups instead of processes. Not all signals are available on all platforms.

   pid = fork do
      Signal.trap("HUP") { puts "Ouch!"; exit }
      # ... do some work ...
   end
   # ...
   Process.kill("HUP", pid)
   Process.wait

produces:

   Ouch!

[Source]

/*
 *  call-seq:
 *     Process.kill(signal, pid, ...)    => fixnum
 *  
 *  Sends the given signal to the specified process id(s), or to the
 *  current process if _pid_ is zero. _signal_ may be an
 *  integer signal number or a POSIX signal name (either with or without
 *  a +SIG+ prefix). If _signal_ is negative (or starts
 *  with a minus sign), kills process groups instead of
 *  processes. Not all signals are available on all platforms.
 *     
 *     pid = fork do
 *        Signal.trap("HUP") { puts "Ouch!"; exit }
 *        # ... do some work ...
 *     end
 *     # ...
 *     Process.kill("HUP", pid)
 *     Process.wait
 *     
 *  <em>produces:</em>
 *     
 *     Ouch!
 */

VALUE
rb_f_kill(argc, argv)
    int argc;
    VALUE *argv;
{
    int negative = 0;
    int sig;
    int i;
    const char *s;

    rb_secure(2);
    if (argc < 2)
	rb_raise(rb_eArgError, "wrong number of arguments -- kill(sig, pid...)");
    switch (TYPE(argv[0])) {
      case T_FIXNUM:
	sig = FIX2INT(argv[0]);
	break;

      case T_SYMBOL:
	s = rb_id2name(SYM2ID(argv[0]));
	if (!s) rb_raise(rb_eArgError, "bad signal");
	goto str_signal;

      case T_STRING:
	s = RSTRING(argv[0])->ptr;
	if (s[0] == '-') {
	    negative++;
	    s++;
	}
      str_signal:
	if (strncmp("SIG", s, 3) == 0)
	    s += 3;
	if((sig = signm2signo(s)) == 0)
	    rb_raise(rb_eArgError, "unsupported name `SIG%s'", s);

	if (negative)
	    sig = -sig;
	break;

      default:
        {
	    VALUE str;

	    str = rb_check_string_type(argv[0]);
	    if (!NIL_P(str)) {
		s = RSTRING(str)->ptr;
		goto str_signal;
	    }
	    rb_raise(rb_eArgError, "bad signal type %s",
		     rb_obj_classname(argv[0]));
	}
	break;
    }

    if (sig < 0) {
	sig = -sig;
	for (i=1; i<argc; i++) {
	    int pid = NUM2INT(argv[i]);
#ifdef HAS_KILLPG
	    if (killpg(pid, sig) < 0)
#else
	    if (kill(-pid, sig) < 0)
#endif
		rb_sys_fail(0);
	}
    }
    else {
	for (i=1; i<argc; i++) {
	    Check_Type(argv[i], T_FIXNUM);
	    if (kill(FIX2INT(argv[i]), sig) < 0)
		rb_sys_fail(0);
	}
    }
    return INT2FIX(i-1);
}

Returns the maximum number of gids allowed in the supplemental group access list.

   Process.maxgroups   #=> 32

[Source]

/*
 *  call-seq:
 *     Process.maxgroups   => fixnum
 *
 *  Returns the maximum number of gids allowed in the supplemental
 *  group access list.
 *
 *     Process.maxgroups   #=> 32
 */

static VALUE
proc_getmaxgroups(obj)
    VALUE obj;
{
    return INT2FIX(maxgroups);
}

Sets the maximum number of gids allowed in the supplemental group access list.

[Source]

/*
 *  call-seq:
 *     Process.maxgroups= fixnum   => fixnum
 *
 *  Sets the maximum number of gids allowed in the supplemental group
 *  access list.
 */

static VALUE
proc_setmaxgroups(VALUE obj, VALUE val)
{
    size_t  ngroups = FIX2INT(val);

    if (ngroups > 4096)
        ngroups = 4096;

    maxgroups = ngroups;

    return INT2FIX(maxgroups);
}

Returns the process id of this process. Not available on all platforms.

   Process.pid   #=> 27415

[Source]

/*
 *  call-seq:
 *     Process.pid   => fixnum
 *
 *  Returns the process id of this process. Not available on all
 *  platforms.
 *
 *     Process.pid   #=> 27415
 */

static VALUE
get_pid()
{
    rb_secure(2);
    return INT2FIX(getpid());
}

Returns the process id of the parent of this process. Always returns 0 on NT. Not available on all platforms.

   puts "I am #{Process.pid}"
   Process.fork { puts "Dad is #{Process.ppid}" }

produces:

   I am 27417
   Dad is 27417

[Source]

/*
 *  call-seq:
 *     Process.ppid   => fixnum
 *
 *  Returns the process id of the parent of this process. Always
 *  returns 0 on NT. Not available on all platforms.
 *
 *     puts "I am #{Process.pid}"
 *     Process.fork { puts "Dad is #{Process.ppid}" }
 *
 *  <em>produces:</em>
 *
 *     I am 27417
 *     Dad is 27417
 */

static VALUE
get_ppid()
{
    rb_secure(2);
#ifdef _WIN32
    return INT2FIX(0);
#else
    return INT2FIX(getppid());
#endif
}

Sets the process group ID of pid (0 indicates this process) to integer. Not available on all platforms.

[Source]

/*
 *  call-seq:
 *     Process.setpgid(pid, integer)   => 0
 *
 *  Sets the process group ID of _pid_ (0 indicates this
 *  process) to <em>integer</em>. Not available on all platforms.
 */

static VALUE
proc_setpgid(obj, pid, pgrp)
    VALUE obj, pid, pgrp;
{
#ifdef HAVE_SETPGID
    int ipid, ipgrp;

    rb_secure(2);
    ipid = NUM2INT(pid);
    ipgrp = NUM2INT(pgrp);

    if (setpgid(ipid, ipgrp) < 0) rb_sys_fail(0);
    return INT2FIX(0);
#else
    rb_notimplement();
#endif
}

Equivalent to setpgid(0,0). Not available on all platforms.

[Source]

/*
 *  call-seq:
 *     Process.setpgrp   => 0
 *
 *  Equivalent to <code>setpgid(0,0)</code>. Not available on all
 *  platforms.
 */

static VALUE
proc_setpgrp()
{
    rb_secure(2);
  /* check for posix setpgid() first; this matches the posix */
  /* getpgrp() above.  It appears that configure will set SETPGRP_VOID */
  /* even though setpgrp(0,0) would be prefered. The posix call avoids */
  /* this confusion. */
#ifdef HAVE_SETPGID
    if (setpgid(0,0) < 0) rb_sys_fail(0);
#elif defined(HAVE_SETPGRP) && defined(SETPGRP_VOID)
    if (setpgrp() < 0) rb_sys_fail(0);
#else
    rb_notimplement();
#endif
    return INT2FIX(0);
}

See Process#getpriority.

   Process.setpriority(Process::PRIO_USER, 0, 19)      #=> 0
   Process.setpriority(Process::PRIO_PROCESS, 0, 19)   #=> 0
   Process.getpriority(Process::PRIO_USER, 0)          #=> 19
   Process.getpriority(Process::PRIO_PROCESS, 0)       #=> 19

[Source]

/*
 *  call-seq:
 *     Process.setpriority(kind, integer, priority)   => 0
 *
 *  See <code>Process#getpriority</code>.
 *
 *     Process.setpriority(Process::PRIO_USER, 0, 19)      #=> 0
 *     Process.setpriority(Process::PRIO_PROCESS, 0, 19)   #=> 0
 *     Process.getpriority(Process::PRIO_USER, 0)          #=> 19
 *     Process.getpriority(Process::PRIO_PROCESS, 0)       #=> 19
 */

static VALUE
proc_setpriority(obj, which, who, prio)
    VALUE obj, which, who, prio;
{
#ifdef HAVE_GETPRIORITY
    int iwhich, iwho, iprio;

    rb_secure(2);
    iwhich = NUM2INT(which);
    iwho   = NUM2INT(who);
    iprio  = NUM2INT(prio);

    if (setpriority(iwhich, iwho, iprio) < 0)
        rb_sys_fail(0);
    return INT2FIX(0);
#else
    rb_notimplement();
#endif
}

Sets the resource limit of the process. cur_limit means current (soft) limit and max_limit means maximum (hard) limit.

If max_limit is not given, cur_limit is used.

resource indicates the kind of resource to limit. The list of resources are OS dependent. Ruby may support following resources.

Process::RLIMIT_CORE
core size (bytes) (SUSv3)
Process::RLIMIT_CPU
CPU time (seconds) (SUSv3)
Process::RLIMIT_DATA
data segment (bytes) (SUSv3)
Process::RLIMIT_FSIZE
file size (bytes) (SUSv3)
Process::RLIMIT_NOFILE
file descriptors (number) (SUSv3)
Process::RLIMIT_STACK
stack size (bytes) (SUSv3)
Process::RLIMIT_AS
total available memory (bytes) (SUSv3, NetBSD, FreeBSD, OpenBSD but 4.4BSD-Lite)
Process::RLIMIT_MEMLOCK
total size for mlock(2) (bytes) (4.4BSD, GNU/Linux)
Process::RLIMIT_NPROC
number of processes for the user (number) (4.4BSD, GNU/Linux)
Process::RLIMIT_RSS
resident memory size (bytes) (4.2BSD, GNU/Linux)
Process::RLIMIT_SBSIZE
all socket buffers (bytes) (NetBSD, FreeBSD)

Other Process::RLIMIT_??? constants may be defined.

cur_limit and max_limit may be Process::RLIM_INFINITY, which means that the resource is not limited. They may be Process::RLIM_SAVED_MAX or Process::RLIM_SAVED_CUR too. See system setrlimit(2) manual for details.

[Source]

/*
 *  call-seq:
 *     Process.setrlimit(resource, cur_limit, max_limit)        => nil
 *     Process.setrlimit(resource, cur_limit)                   => nil
 *
 *  Sets the resource limit of the process.
 *  _cur_limit_ means current (soft) limit and
 *  _max_limit_ means maximum (hard) limit.
 *
 *  If _max_limit_ is not given, _cur_limit_ is used.
 *
 *  _resource_ indicates the kind of resource to limit.
 *  The list of resources are OS dependent.
 *  Ruby may support following resources.
 *
 *  [Process::RLIMIT_CORE] core size (bytes) (SUSv3)
 *  [Process::RLIMIT_CPU] CPU time (seconds) (SUSv3)
 *  [Process::RLIMIT_DATA] data segment (bytes) (SUSv3)
 *  [Process::RLIMIT_FSIZE] file size (bytes) (SUSv3)
 *  [Process::RLIMIT_NOFILE] file descriptors (number) (SUSv3)
 *  [Process::RLIMIT_STACK] stack size (bytes) (SUSv3)
 *  [Process::RLIMIT_AS] total available memory (bytes) (SUSv3, NetBSD, FreeBSD, OpenBSD but 4.4BSD-Lite)
 *  [Process::RLIMIT_MEMLOCK] total size for mlock(2) (bytes) (4.4BSD, GNU/Linux)
 *  [Process::RLIMIT_NPROC] number of processes for the user (number) (4.4BSD, GNU/Linux)
 *  [Process::RLIMIT_RSS] resident memory size (bytes) (4.2BSD, GNU/Linux)
 *  [Process::RLIMIT_SBSIZE] all socket buffers (bytes) (NetBSD, FreeBSD)
 *
 *  Other <code>Process::RLIMIT_???</code> constants may be defined.
 *
 *  _cur_limit_ and _max_limit_ may be <code>Process::RLIM_INFINITY</code>,
 *  which means that the resource is not limited.
 *  They may be <code>Process::RLIM_SAVED_MAX</code> or
 *  <code>Process::RLIM_SAVED_CUR</code> too.
 *  See system setrlimit(2) manual for details.
 *
 */

static VALUE
proc_setrlimit(int argc, VALUE *argv, VALUE obj)
{
#if defined(HAVE_SETRLIMIT) && defined(NUM2RLIM)
    VALUE resource, rlim_cur, rlim_max;
    struct rlimit rlim;

    rb_secure(2);

    rb_scan_args(argc, argv, "21", &resource, &rlim_cur, &rlim_max);
    if (rlim_max == Qnil)
        rlim_max = rlim_cur;

    rlim.rlim_cur = NUM2RLIM(rlim_cur);
    rlim.rlim_max = NUM2RLIM(rlim_max);

    if (setrlimit(NUM2INT(resource), &rlim) < 0) {
        rb_sys_fail("setrlimit");
    }
    return Qnil;
#else
    rb_notimplement();
#endif
}

Establishes this process as a new session and process group leader, with no controlling tty. Returns the session id. Not available on all platforms.

   Process.setsid   #=> 27422

[Source]

/*
 *  call-seq:
 *     Process.setsid   => fixnum
 *
 *  Establishes this process as a new session and process group
 *  leader, with no controlling tty. Returns the session id. Not
 *  available on all platforms.
 *
 *     Process.setsid   #=> 27422
 */

static VALUE
proc_setsid()
{
#if defined(HAVE_SETSID)
    int pid;

    rb_secure(2);
    pid = setsid();
    if (pid < 0) rb_sys_fail(0);
    return INT2FIX(pid);
#elif defined(HAVE_SETPGRP) && defined(TIOCNOTTY)
  rb_pid_t pid;
  int ret;

  rb_secure(2);
  pid = getpid();
#if defined(SETPGRP_VOID)
  ret = setpgrp();
  /* If `pid_t setpgrp(void)' is equivalent to setsid(),
     `ret' will be the same value as `pid', and following open() will fail.
     In Linux, `int setpgrp(void)' is equivalent to setpgid(0, 0). */
#else
  ret = setpgrp(0, pid);
#endif
  if (ret == -1) rb_sys_fail(0);

  if ((fd = open("/dev/tty", O_RDWR)) >= 0) {
    ioctl(fd, TIOCNOTTY, NULL);
    close(fd);
  }
  return INT2FIX(pid);
#else
    rb_notimplement();
#endif
}

Returns a Tms structure (see Struct::Tms on page 388) that contains user and system CPU times for this process.

   t = Process.times
   [ t.utime, t.stime ]   #=> [0.0, 0.02]

[Source]

/*
 *  call-seq:
 *     Process.times   => aStructTms
 *
 *  Returns a <code>Tms</code> structure (see <code>Struct::Tms</code>
 *  on page 388) that contains user and system CPU times for this
 *  process.
 *
 *     t = Process.times
 *     [ t.utime, t.stime ]   #=> [0.0, 0.02]
 */

VALUE
rb_proc_times(obj)
    VALUE obj;
{
#if defined(HAVE_TIMES) && !defined(__CHECKER__)
    const double hertz =
#ifdef HAVE__SC_CLK_TCK
        (double)sysconf(_SC_CLK_TCK);
#else
#ifndef HZ
# ifdef CLK_TCK
#   define HZ CLK_TCK
# else
#   define HZ 60
# endif
#endif /* HZ */
        HZ;
#endif
    struct tms buf;
    volatile VALUE utime, stime, cutime, sctime;

    times(&buf);
    return rb_struct_new(S_Tms,
                         utime = rb_float_new(buf.tms_utime / hertz),
                         stime = rb_float_new(buf.tms_stime / hertz),
                         cutime = rb_float_new(buf.tms_cutime / hertz),
                         sctime = rb_float_new(buf.tms_cstime / hertz));
#else
    rb_notimplement();
#endif
}

Returns the (real) user ID of this process.

   Process.uid   #=> 501

[Source]

/*
 *  call-seq:
 *     Process.uid           => fixnum
 *     Process::UID.rid      => fixnum
 *     Process::Sys.getuid   => fixnum
 *
 *  Returns the (real) user ID of this process.
 *
 *     Process.uid   #=> 501
 */

static VALUE
proc_getuid(obj)
    VALUE obj;
{
    int uid = getuid();
    return INT2FIX(uid);
}

Sets the (integer) user ID for this process. Not available on all platforms.

[Source]

/*
 *  call-seq:
 *     Process.uid= integer   => numeric
 *
 *  Sets the (integer) user ID for this process. Not available on all
 *  platforms.
 */

static VALUE
proc_setuid(obj, id)
    VALUE obj, id;
{
    int uid = NUM2INT(id);

    check_uid_switch();
#if defined(HAVE_SETRESUID) &&  !defined(__CHECKER__)
    if (setresuid(uid, -1, -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETREUID
    if (setreuid(uid, -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETRUID
    if (setruid(uid) < 0) rb_sys_fail(0);
#elif defined HAVE_SETUID
    {
        if (geteuid() == uid) {
            if (setuid(uid) < 0) rb_sys_fail(0);
        }
        else {
            rb_notimplement();
        }
    }
#else
    rb_notimplement();
#endif
    return INT2FIX(uid);
}

Waits for a child process to exit, returns its process id, and sets $? to a Process::Status object containing information on that process. Which child it waits on depends on the value of pid:

> 0:Waits for the child whose process ID equals pid.
0:Waits for any child whose process group ID equals that of the calling process.
-1:Waits for any child process (the default if no pid is given).
< -1:Waits for any child whose process group ID equals the absolute value of pid.

The flags argument may be a logical or of the flag values Process::WNOHANG (do not block if no child available) or Process::WUNTRACED (return stopped children that haven‘t been reported). Not all flags are available on all platforms, but a flag value of zero will work on all platforms.

Calling this method raises a SystemError if there are no child processes. Not available on all platforms.

   include Process
   fork { exit 99 }                 #=> 27429
   wait                             #=> 27429
   $?.exitstatus                    #=> 99

   pid = fork { sleep 3 }           #=> 27440
   Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
   waitpid(pid, Process::WNOHANG)   #=> nil
   Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
   waitpid(pid, 0)                  #=> 27440
   Time.now                         #=> Wed Apr 09 08:57:12 CDT 2003

[Source]

/*
 *  call-seq:
 *     Process.wait()                     => fixnum
 *     Process.wait(pid=-1, flags=0)      => fixnum
 *     Process.waitpid(pid=-1, flags=0)   => fixnum
 *
 *  Waits for a child process to exit, returns its process id, and
 *  sets <code>$?</code> to a <code>Process::Status</code> object
 *  containing information on that process. Which child it waits on
 *  depends on the value of _pid_:
 *
 *  > 0::   Waits for the child whose process ID equals _pid_.
 *
 *  0::     Waits for any child whose process group ID equals that of the
 *          calling process.
 *
 *  -1::    Waits for any child process (the default if no _pid_ is
 *          given).
 *
 *  < -1::  Waits for any child whose process group ID equals the absolute
 *          value of _pid_.
 *
 *  The _flags_ argument may be a logical or of the flag values
 *  <code>Process::WNOHANG</code> (do not block if no child available)
 *  or <code>Process::WUNTRACED</code> (return stopped children that
 *  haven't been reported). Not all flags are available on all
 *  platforms, but a flag value of zero will work on all platforms.
 *
 *  Calling this method raises a <code>SystemError</code> if there are
 *  no child processes. Not available on all platforms.
 *
 *     include Process
 *     fork { exit 99 }                 #=> 27429
 *     wait                             #=> 27429
 *     $?.exitstatus                    #=> 99
 *
 *     pid = fork { sleep 3 }           #=> 27440
 *     Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
 *     waitpid(pid, Process::WNOHANG)   #=> nil
 *     Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
 *     waitpid(pid, 0)                  #=> 27440
 *     Time.now                         #=> Wed Apr 09 08:57:12 CDT 2003
 */

static VALUE
proc_wait(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE vpid, vflags;
    int pid, flags, status;

    rb_secure(2);
    flags = 0;
    rb_scan_args(argc, argv, "02", &vpid, &vflags);
    if (argc == 0) {
        pid = -1;
    }
    else {
        pid = NUM2INT(vpid);
        if (argc == 2 && !NIL_P(vflags)) {
            flags = NUM2UINT(vflags);
        }
    }
    if ((pid = rb_waitpid(pid, &status, flags)) < 0)
        rb_sys_fail(0);
    if (pid == 0) {
        return rb_last_status = Qnil;
    }
    return INT2FIX(pid);
}

Waits for a child process to exit (see Process::waitpid for exact semantics) and returns an array containing the process id and the exit status (a Process::Status object) of that child. Raises a SystemError if there are no child processes.

   Process.fork { exit 99 }   #=> 27437
   pid, status = Process.wait2
   pid                        #=> 27437
   status.exitstatus          #=> 99

[Source]

/*
 *  call-seq:
 *     Process.wait2(pid=-1, flags=0)      => [pid, status]
 *     Process.waitpid2(pid=-1, flags=0)   => [pid, status]
 *
 *  Waits for a child process to exit (see Process::waitpid for exact
 *  semantics) and returns an array containing the process id and the
 *  exit status (a <code>Process::Status</code> object) of that
 *  child. Raises a <code>SystemError</code> if there are no child
 *  processes.
 *
 *     Process.fork { exit 99 }   #=> 27437
 *     pid, status = Process.wait2
 *     pid                        #=> 27437
 *     status.exitstatus          #=> 99
 */

static VALUE
proc_wait2(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE pid = proc_wait(argc, argv);
    if (NIL_P(pid)) return Qnil;
    return rb_assoc_new(pid, rb_last_status);
}

Waits for all children, returning an array of pid/status pairs (where status is a Process::Status object).

   fork { sleep 0.2; exit 2 }   #=> 27432
   fork { sleep 0.1; exit 1 }   #=> 27433
   fork {            exit 0 }   #=> 27434
   p Process.waitall

produces:

   [[27434, #<Process::Status: pid=27434,exited(0)>],
    [27433, #<Process::Status: pid=27433,exited(1)>],
    [27432, #<Process::Status: pid=27432,exited(2)>]]

[Source]

/*
 *  call-seq:
 *     Process.waitall   => [ [pid1,status1], ...]
 *
 *  Waits for all children, returning an array of
 *  _pid_/_status_ pairs (where _status_ is a
 *  <code>Process::Status</code> object).
 *
 *     fork { sleep 0.2; exit 2 }   #=> 27432
 *     fork { sleep 0.1; exit 1 }   #=> 27433
 *     fork {            exit 0 }   #=> 27434
 *     p Process.waitall
 *
 *  <em>produces</em>:
 *
 *     [[27434, #<Process::Status: pid=27434,exited(0)>],
 *      [27433, #<Process::Status: pid=27433,exited(1)>],
 *      [27432, #<Process::Status: pid=27432,exited(2)>]]
 */

static VALUE
proc_waitall()
{
    VALUE result;
    int pid, status;

    rb_secure(2);
    result = rb_ary_new();
#ifdef NO_WAITPID
    if (pid_tbl) {
        st_foreach(pid_tbl, waitall_each, result);
    }

    for (pid = -1;;) {
        pid = wait(&status);
        if (pid == -1) {
            if (errno == ECHILD)
                break;
            if (errno == EINTR) {
                rb_thread_schedule();
                continue;
            }
            rb_sys_fail(0);
        }
        last_status_set(status, pid);
        rb_ary_push(result, rb_assoc_new(INT2NUM(pid), rb_last_status));
    }
#else
    rb_last_status = Qnil;
    for (pid = -1;;) {
        pid = rb_waitpid(-1, &status, 0);
        if (pid == -1) {
            if (errno == ECHILD)
                break;
            rb_sys_fail(0);
        }
        rb_ary_push(result, rb_assoc_new(INT2NUM(pid), rb_last_status));
    }
#endif
    return result;
}

Waits for a child process to exit, returns its process id, and sets $? to a Process::Status object containing information on that process. Which child it waits on depends on the value of pid:

> 0:Waits for the child whose process ID equals pid.
0:Waits for any child whose process group ID equals that of the calling process.
-1:Waits for any child process (the default if no pid is given).
< -1:Waits for any child whose process group ID equals the absolute value of pid.

The flags argument may be a logical or of the flag values Process::WNOHANG (do not block if no child available) or Process::WUNTRACED (return stopped children that haven‘t been reported). Not all flags are available on all platforms, but a flag value of zero will work on all platforms.

Calling this method raises a SystemError if there are no child processes. Not available on all platforms.

   include Process
   fork { exit 99 }                 #=> 27429
   wait                             #=> 27429
   $?.exitstatus                    #=> 99

   pid = fork { sleep 3 }           #=> 27440
   Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
   waitpid(pid, Process::WNOHANG)   #=> nil
   Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
   waitpid(pid, 0)                  #=> 27440
   Time.now                         #=> Wed Apr 09 08:57:12 CDT 2003

[Source]

/*
 *  call-seq:
 *     Process.wait()                     => fixnum
 *     Process.wait(pid=-1, flags=0)      => fixnum
 *     Process.waitpid(pid=-1, flags=0)   => fixnum
 *
 *  Waits for a child process to exit, returns its process id, and
 *  sets <code>$?</code> to a <code>Process::Status</code> object
 *  containing information on that process. Which child it waits on
 *  depends on the value of _pid_:
 *
 *  > 0::   Waits for the child whose process ID equals _pid_.
 *
 *  0::     Waits for any child whose process group ID equals that of the
 *          calling process.
 *
 *  -1::    Waits for any child process (the default if no _pid_ is
 *          given).
 *
 *  < -1::  Waits for any child whose process group ID equals the absolute
 *          value of _pid_.
 *
 *  The _flags_ argument may be a logical or of the flag values
 *  <code>Process::WNOHANG</code> (do not block if no child available)
 *  or <code>Process::WUNTRACED</code> (return stopped children that
 *  haven't been reported). Not all flags are available on all
 *  platforms, but a flag value of zero will work on all platforms.
 *
 *  Calling this method raises a <code>SystemError</code> if there are
 *  no child processes. Not available on all platforms.
 *
 *     include Process
 *     fork { exit 99 }                 #=> 27429
 *     wait                             #=> 27429
 *     $?.exitstatus                    #=> 99
 *
 *     pid = fork { sleep 3 }           #=> 27440
 *     Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
 *     waitpid(pid, Process::WNOHANG)   #=> nil
 *     Time.now                         #=> Wed Apr 09 08:57:09 CDT 2003
 *     waitpid(pid, 0)                  #=> 27440
 *     Time.now                         #=> Wed Apr 09 08:57:12 CDT 2003
 */

static VALUE
proc_wait(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE vpid, vflags;
    int pid, flags, status;

    rb_secure(2);
    flags = 0;
    rb_scan_args(argc, argv, "02", &vpid, &vflags);
    if (argc == 0) {
        pid = -1;
    }
    else {
        pid = NUM2INT(vpid);
        if (argc == 2 && !NIL_P(vflags)) {
            flags = NUM2UINT(vflags);
        }
    }
    if ((pid = rb_waitpid(pid, &status, flags)) < 0)
        rb_sys_fail(0);
    if (pid == 0) {
        return rb_last_status = Qnil;
    }
    return INT2FIX(pid);
}

Waits for a child process to exit (see Process::waitpid for exact semantics) and returns an array containing the process id and the exit status (a Process::Status object) of that child. Raises a SystemError if there are no child processes.

   Process.fork { exit 99 }   #=> 27437
   pid, status = Process.wait2
   pid                        #=> 27437
   status.exitstatus          #=> 99

[Source]

/*
 *  call-seq:
 *     Process.wait2(pid=-1, flags=0)      => [pid, status]
 *     Process.waitpid2(pid=-1, flags=0)   => [pid, status]
 *
 *  Waits for a child process to exit (see Process::waitpid for exact
 *  semantics) and returns an array containing the process id and the
 *  exit status (a <code>Process::Status</code> object) of that
 *  child. Raises a <code>SystemError</code> if there are no child
 *  processes.
 *
 *     Process.fork { exit 99 }   #=> 27437
 *     pid, status = Process.wait2
 *     pid                        #=> 27437
 *     status.exitstatus          #=> 99
 */

static VALUE
proc_wait2(argc, argv)
    int argc;
    VALUE *argv;
{
    VALUE pid = proc_wait(argc, argv);
    if (NIL_P(pid)) return Qnil;
    return rb_assoc_new(pid, rb_last_status);
}

[Validate]