Module: Process (Ruby 1.9.1)

abort click to toggle source

Kernel::abort

Process::abort

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

 
               VALUE
rb_f_abort(int argc, VALUE *argv)
{
    extern void ruby_error_print(void);

    rb_secure(4);
    if (argc == 0) {
        if (!NIL_P(GET_THREAD()->errinfo)) {
            ruby_error_print();
        }
        rb_exit(EXIT_FAILURE);
    }
    else {
        VALUE args[2];

        rb_scan_args(argc, argv, "1", &args[1]);
        StringValue(argv[0]);
        rb_io_puts(argc, argv, rb_stderr);
        args[0] = INT2NUM(EXIT_FAILURE);
        rb_exc_raise(rb_class_new_instance(2, args, rb_eSystemExit));
    }
    return Qnil;                /* not reached */
}

daemon() => fixnum click to toggle source

daemon(nochdir=nil,noclose=nil) => fixnum

Detach the process from controlling terminal and run in the background as system daemon. Unless the argument nochdir is true (i.e. non false), it changes the current working directory to the root (“/”). Unless the argument noclose is true, daemon() will redirect standard input, standard output and standard error to /dev/null.

 
               static VALUE
proc_daemon(int argc, VALUE *argv)
{
    VALUE nochdir, noclose;
#if defined(HAVE_DAEMON) || defined(HAVE_FORK)
    int n;
#endif

    rb_secure(2);
    rb_scan_args(argc, argv, "02", &nochdir, &noclose);

#if defined(HAVE_DAEMON)
    prefork();
    before_fork();
    n = daemon(RTEST(nochdir), RTEST(noclose));
    after_fork();
    if (n < 0) rb_sys_fail("daemon");
    return INT2FIX(n);
#elif defined(HAVE_FORK)
    switch (rb_fork(0, 0, 0, Qnil)) {
      case -1:
        return INT2FIX(-1);
      case 0:
        break;
      default:
        _exit(0);
    }

    proc_setsid();

    /* must not be process-leader */
    switch (rb_fork(0, 0, 0, Qnil)) {
      case -1:
        return INT2FIX(-1);
      case 0:
        break;
      default:
        _exit(0);
    }

    if (!RTEST(nochdir))
        (void)chdir("/");

    if (!RTEST(noclose) && (n = open("/dev/null", O_RDWR, 0)) != -1) {
        (void)dup2(n, 0);
        (void)dup2(n, 1);
        (void)dup2(n, 2);
        if (n > 2)
            (void)close (n);
    }
    return INT2FIX(0);
#else
    rb_notimplement();
#endif
}

detach(pid) => thread click to toggle source

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.

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)

 
               static VALUE
proc_detach(VALUE obj, VALUE pid)
{
    rb_secure(2);
    return rb_detach_process(NUM2PIDT(pid));
}

egid => fixnum click to toggle source

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(VALUE obj)
{
    rb_gid_t egid = getegid();

    return GIDT2NUM(egid);
}

egid = fixnum => fixnum click to toggle source

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

 
               static VALUE
proc_setegid(VALUE obj, VALUE egid)
{
    rb_gid_t gid;

    check_gid_switch();

    gid = NUM2GIDT(egid);
#if defined(HAVE_SETRESGID) && !defined(__CHECKER__)
    if (setresgid(-1, gid, -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETREGID
    if (setregid(-1, gid) < 0) rb_sys_fail(0);
#elif defined HAVE_SETEGID
    if (setegid(gid) < 0) rb_sys_fail(0);
#elif defined HAVE_SETGID
    if (gid == getgid()) {
        if (setgid(gid) < 0) rb_sys_fail(0);
    }
    else {
        rb_notimplement();
    }
#else
    rb_notimplement();
#endif
    return egid;
}

euid => fixnum click to toggle source

Process::UID.eid => fixnum

Process::Sys.geteuid => fixnum

Returns the effective user ID for this process.

Process.euid   #=> 501

 
               static VALUE
proc_geteuid(VALUE obj)
{
    rb_uid_t euid = geteuid();
    return UIDT2NUM(euid);
}

euid= integer click to toggle source

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

 
               static VALUE
proc_seteuid(VALUE obj, VALUE euid)
{
    rb_uid_t uid;

    check_uid_switch();

    uid = NUM2UIDT(euid);
#if defined(HAVE_SETRESUID) && !defined(__CHECKER__)
    if (setresuid(-1, uid, -1) < 0) rb_sys_fail(0);
#elif defined HAVE_SETREUID
    if (setreuid(-1, uid) < 0) rb_sys_fail(0);
#elif defined HAVE_SETEUID
    if (seteuid(uid) < 0) rb_sys_fail(0);
#elif defined HAVE_SETUID
    if (uid == getuid()) {
        if (setuid(uid) < 0) rb_sys_fail(0);
    }
    else {
        rb_notimplement();
    }
#else
    rb_notimplement();
#endif
    return euid;
}

exec([env,] command [, arg, ...] [,options]) click to toggle source

Replaces the current process by running the given external command. If optional arguments, sequence of arg, are not given, that argument is taken as a line that is subject to shell expansion before being executed. If one or more arg given, they are passed as parameters to command with no shell expansion. If command 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 order to execute the command, 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).

The hash arguments, env and options, are same as system and spawn. See spawn for details.

Raises SystemCallError if the command couldn't execute (typically Errno::ENOENT when it was not found).

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

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

 
               VALUE
rb_f_exec(int argc, VALUE *argv)
{
    struct rb_exec_arg earg;

    rb_exec_arg_init(argc, argv, Qtrue, &earg);
    if (NIL_P(rb_ary_entry(earg.options, EXEC_OPTION_CLOSE_OTHERS)))
        rb_exec_arg_addopt(&earg, ID2SYM(rb_intern("close_others")), Qfalse);
    rb_exec_arg_fixup(&earg);

    rb_exec(&earg);
    rb_sys_fail(earg.prog);
    return Qnil;                /* dummy */
}

exit(integer=0) click to toggle source

Kernel::exit(integer=0)

Process::exit(integer=0)

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

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

    rb_secure(4);
    if (argc > 0 && 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 */
}

exit!(fixnum=-1) click to toggle source

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

Process.exit!(0)

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

    rb_secure(4);
    if (argc > 0 && 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 */
}

fork [{ block }] => fixnum or nil click to toggle source

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 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.

 
               static VALUE
rb_f_fork(VALUE obj)
{
#if defined(HAVE_FORK) && !defined(CANNOT_FORK_WITH_PTHREAD)
    rb_pid_t pid;

    rb_secure(2);

    switch (pid = rb_fork(0, 0, 0, Qnil)) {
      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 PIDT2NUM(pid);
    }
#else
    rb_notimplement();
#endif
}

getpgid(pid) => integer click to toggle source

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

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

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

    rb_secure(2);
    i = getpgid(NUM2PIDT(pid));
    if (i < 0) rb_sys_fail(0);
    return PIDT2NUM(i);
#else
    rb_notimplement();
#endif
}

getpgrp => integer click to toggle source

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

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

 
               static VALUE
proc_getpgrp(void)
{
#if defined(HAVE_GETPGRP) && defined(GETPGRP_VOID) || defined(HAVE_GETPGID)
    rb_pid_t pgrp;
#endif

    rb_secure(2);
#if defined(HAVE_GETPGRP) && defined(GETPGRP_VOID)
    pgrp = getpgrp();
    if (pgrp < 0) rb_sys_fail(0);
    return PIDT2NUM(pgrp);
#else
# ifdef HAVE_GETPGID
    pgrp = getpgid(0);
    if (pgrp < 0) rb_sys_fail(0);
    return PIDT2NUM(pgrp);
# else
    rb_notimplement();
# endif
#endif
}

getpriority(kind, integer) => fixnum click to toggle source

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

 
               static VALUE
proc_getpriority(VALUE obj, VALUE which, VALUE 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
}

getrlimit(resource) => [cur_limit, max_limit] click to toggle source

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. It is specified as a symbol such as :CORE, a string such as "CORE" or a constant such as Process::RLIMIT_CORE. See ::setrlimit for details.

cur_limit and max_limit may be Process::RLIM_INFINITY, Process::RLIM_SAVED_MAX or Process::RLIM_SAVED_CUR. See ::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(rlimit_resource_type(resource), &rlim) < 0) {
        rb_sys_fail("getrlimit");
    }
    return rb_assoc_new(RLIM2NUM(rlim.rlim_cur), RLIM2NUM(rlim.rlim_max));
#else
    rb_notimplement();
#endif
}

gid => fixnum click to toggle source

Process::GID.rid => fixnum

Process::Sys.getgid => fixnum

Returns the (real) group ID for this process.

Process.gid   #=> 500

 
               static VALUE
proc_getgid(VALUE obj)
{
    rb_gid_t gid = getgid();
    return GIDT2NUM(gid);
}

gid= fixnum => fixnum click to toggle source

Sets the group ID for this process.

 
               static VALUE
proc_setgid(VALUE obj, VALUE id)
{
    rb_gid_t gid;

    check_gid_switch();

    gid = NUM2GIDT(id);
#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 GIDT2NUM(gid);
}

groups => array click to toggle source

Get an Array 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, GIDT2NUM(groups[i]));

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

groups= array => array click to toggle source

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]

 
               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_LEN(ary);
    if (ngroups > maxgroups)
        rb_raise(rb_eArgError, "too many groups, %lu max", (unsigned long)maxgroups);

    groups = ALLOCA_N(rb_gid_t, ngroups);

    for (i = 0; i < ngroups && i < RARRAY_LEN(ary); i++) {
        VALUE g = RARRAY_PTR(ary)[i];

        if (FIXNUM_P(g)) {
            groups[i] = NUM2GIDT(g);
        }
        else {
            VALUE tmp = rb_check_string_type(g);

            if (NIL_P(tmp)) {
                groups[i] = NUM2GIDT(g);
            }
            else {
                gr = getgrnam(RSTRING_PTR(tmp));
                if (gr == NULL)
                    rb_raise(rb_eArgError,
                             "can't find group for %s", RSTRING_PTR(tmp));
                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
}

initgroups(username, gid) => array click to toggle source

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]

 
               static VALUE
proc_initgroups(VALUE obj, VALUE uname, VALUE base_grp)
{
#ifdef HAVE_INITGROUPS
    if (initgroups(StringValuePtr(uname), NUM2GIDT(base_grp)) != 0) {
        rb_sys_fail(0);
    }
    return proc_getgroups(obj);
#else
    rb_notimplement();
    return Qnil;
#endif
}

kill(signal, pid, ...) => fixnum click to toggle source

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!

 
               VALUE
rb_f_kill(int argc, VALUE *argv)
{
#ifndef HAS_KILLPG
#define killpg(pg, sig) kill(-(pg), sig)
#endif
    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_PTR(argv[0]);
	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_PTR(str);
		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++) {
	    if (killpg(NUM2PIDT(argv[i]), sig) < 0)
		rb_sys_fail(0);
	}
    }
    else {
	for (i=1; i<argc; i++) {
	    if (kill(NUM2PIDT(argv[i]), sig) < 0)
		rb_sys_fail(0);
	}
    }
    rb_thread_polling();
    return INT2FIX(i-1);
}

maxgroups => fixnum click to toggle source

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

Process.maxgroups   #=> 32

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

maxgroups= fixnum => fixnum click to toggle source

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);
}

pid => fixnum click to toggle source

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

Process.pid   #=> 27415

 
               static VALUE
get_pid(void)
{
    rb_secure(2);
    return PIDT2NUM(getpid());
}

ppid => fixnum click to toggle source

Returns the process id of the parent of this process. Returns untrustworthy value on Win32/64. Not available on all platforms.

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

produces:

I am 27417
Dad is 27417

 
               static VALUE
get_ppid(void)
{
    rb_secure(2);
    return PIDT2NUM(getppid());
}

setpgid(pid, integer) => 0 click to toggle source

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

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

    rb_secure(2);
    ipid = NUM2PIDT(pid);
    ipgrp = NUM2PIDT(pgrp);

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

setpgrp => 0 click to toggle source

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

 
               static VALUE
proc_setpgrp(void)
{
    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 preferred. 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);
}

setpriority(kind, integer, priority) => 0 click to toggle source

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

 
               static VALUE
proc_setpriority(VALUE obj, VALUE which, VALUE who, VALUE 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
}

setrlimit(resource, cur_limit, max_limit) => nil click to toggle source

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. It should be a symbol such as :CORE, a string such as "CORE" or a constant such as Process::RLIMIT_CORE. The available resources are OS dependent. Ruby may support following resources.

CORE: core size (bytes) (SUSv3)
CPU: CPU time (seconds) (SUSv3)
DATA: data segment (bytes) (SUSv3)
FSIZE: file size (bytes) (SUSv3)
NOFILE: file descriptors (number) (SUSv3)
STACK: stack size (bytes) (SUSv3)
AS: total available memory (bytes) (SUSv3, NetBSD, FreeBSD, OpenBSD but 4.4BSD-Lite)
MEMLOCK: total size for mlock(2) (bytes) (4.4BSD, GNU/Linux)
NPROC: number of processes for the user (number) (4.4BSD, GNU/Linux)
RSS: resident memory size (bytes) (4.2BSD, GNU/Linux)
SBSIZE: all socket buffers (bytes) (NetBSD, FreeBSD)

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

The following example raise the soft limit of core size to the hard limit to try to make core dump possible.

Process.setrlimit(:CORE, Process.getrlimit(:CORE)[1])

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

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

setsid => fixnum click to toggle source

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(void)
{
#if defined(HAVE_SETSID)
    rb_pid_t pid;

    rb_secure(2);
    pid = setsid();
    if (pid < 0) rb_sys_fail(0);
    return PIDT2NUM(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 PIDT2NUM(pid);
#else
    rb_notimplement();
#endif
}

spawn([env,] cmd [, arg, ...] [,options]) => pid click to toggle source

Similar to Kernel::system except for not waiting for end of cmd, but returns its pid.

If a hash is given as env, the environment is updated by env before exec(2) in the child process. If a pair in env has nil as the value, the variable is deleted.

# set FOO as BAR and unset BAZ.
pid = spawn({"FOO"=>"BAR", "BAZ"=>nil}, command)

If a hash is given as options, it specifies process group, resource limit, current directory, umask and redirects for the child process. Also, it can be specified to clear environment variables.

The :unsetenv_others key in options specifies to clear environment variables, other than specified by env.

pid = spawn(command, :unsetenv_others=>true) # no environment variable
pid = spawn({"FOO"=>"BAR"}, command, :unsetenv_others=>true) # FOO only

The :pgroup key in options specifies a process group. The corresponding value should be true, zero or positive integer. true and zero means the process should be a process leader. Other values specifies a process group to be belongs.

pid = spawn(command, :pgroup=>true) # process leader
pid = spawn(command, :pgroup=>10) # belongs to the process group 10

The :rlimit_foo key specifies a resource limit. foo should be one of resource types such as core The corresponding value should be an integer or an array which have one or two integers: same as cur_limit and max_limit arguments for ::setrlimit.

pid = spawn(command, :rlimit_core=>0) # never dump core.
cur, max = Process.getrlimit(:CORE)
pid = spawn(command, :rlimit_core=>[0,max]) # disable core temporary.
pid = spawn(command, :rlimit_core=>max) # enable core dump

The :chdir key in options specifies the current directory.

pid = spawn(command, :chdir=>"/var/tmp")

The :umask key in options specifies the umask.

pid = spawn(command, :umask=>077)

The :in, :out, :err, a fixnum, an IO and an array key specifies a redirect. The redirection maps a file descriptor in the child process.

For example, stderr can be merged into stdout:

pid = spawn(command, :err=>:out)
pid = spawn(command, STDERR=>STDOUT)
pid = spawn(command, 2=>1)

The hash keys specifies a file descriptor in the child process started by spawn. :err, STDERR and 2 specifies the standard error stream.

The hash values specifies a file descriptor in the parent process which invokes spawn. :out, STDOUT and 1 specifies the standard output stream.

The standard output in the child process is not specified. So it is inherited from the parent process.

The standard input stream can be specifed by :in, STDIN and 0.

A filename can be specified as a hash value.

pid = spawn(command, STDIN=>"/dev/null") # read mode
pid = spawn(command, STDOUT=>"/dev/null") # write mode
pid = spawn(command, STDERR=>"log") # write mode
pid = spawn(command, 3=>"/dev/null") # read mode

For standard output and standard error, it is opened in write mode. Otherwise read mode is used.

For specifying flags and permission of file creation explicitly, an array is used instead.

pid = spawn(command, STDIN=>["file"]) # read mode is assumed
pid = spawn(command, STDIN=>["file", "r"])
pid = spawn(command, STDOUT=>["log", "w"]) # 0644 assumed
pid = spawn(command, STDOUT=>["log", "w", 0600])
pid = spawn(command, STDOUT=>["log", File::WRONLY|File::EXCL|File::CREAT, 0600])

The array specifies a filename, flags and permission. The flags can be a string or an integer. If the flags is ommitted or nil, File::RDONLY is assumed. The permission should be an integer. If the permission is ommitted or nil, 0644 is assumed.

If an array of IOs and integers are specified as a hash key, all the elemetns are redirected.

# standard output and standard error is redirected to log file.
pid = spawn(command, [STDOUT, STDERR]=>["log", "w"])

spawn closes all non-standard unspecified descriptors by default. The “standard” descriptors are 0, 1 and 2. This behavior is specified by :close_others option. :close_others doesn't affect the standard descriptors which are closed only if :close is specified explicitly.

pid = spawn(command, :close_others=>true)  # close 3,4,5,... (default)
pid = spawn(command, :close_others=>false) # don't close 3,4,5,...

:close_others is true by default for spawn and IO.popen.

So IO.pipe and spawn can be used as IO.popen.

# similar to r = IO.popen(command)
r, w = IO.pipe
pid = spawn(command, STDOUT=>w)   # r, w is closed in the child process.
w.close

:close is specified as a hash value to close a fd individualy.

f = open(foo)
system(command, f=>:close)        # don't inherit f.

It is also possible to exchange file descriptors.

pid = spawn(command, STDOUT=>STDERR, STDERR=>STDOUT)

The hash keys specify file descriptors in the child process. The hash values specifies file descriptors in the parent process. So the above specifies exchanging STDOUT and STDERR. Internally, spawn uses an extra file descriptor to resolve such cyclic file descriptor mapping.

 
               static VALUE
rb_f_spawn(int argc, VALUE *argv)
{
    rb_pid_t pid;

    pid = rb_spawn(argc, argv);
    if (pid == -1) rb_sys_fail(RSTRING_PTR(argv[0]));
#if defined(HAVE_FORK) || defined(HAVE_SPAWNV)
    return PIDT2NUM(pid);
#else
    return Qnil;
#endif
}

times => aStructTms click to toggle source

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]

 
               VALUE
rb_proc_times(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(rb_cProcessTms,
                         utime = DBL2NUM(buf.tms_utime / hertz),
                         stime = DBL2NUM(buf.tms_stime / hertz),
                         cutime = DBL2NUM(buf.tms_cutime / hertz),
                         sctime = DBL2NUM(buf.tms_cstime / hertz));
#else
    rb_notimplement();
#endif
}

uid => fixnum click to toggle source

Process::UID.rid => fixnum

Process::Sys.getuid => fixnum

Returns the (real) user ID of this process.

Process.uid   #=> 501

 
               static VALUE
proc_getuid(VALUE obj)
{
    rb_uid_t uid = getuid();
    return UIDT2NUM(uid);
}

uid= integer => numeric click to toggle source

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

 
               static VALUE
proc_setuid(VALUE obj, VALUE id)
{
    rb_uid_t uid;

    check_uid_switch();

    uid = NUM2UIDT(id);
#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 id;
}

wait() => fixnum click to toggle source

wait(pid=-1, flags=0) => fixnum

waitpid(pid=-1, flags=0) => fixnum

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                         #=> 2008-03-08 19:56:16 +0900
waitpid(pid, Process::WNOHANG)   #=> nil
Time.now                         #=> 2008-03-08 19:56:16 +0900
waitpid(pid, 0)                  #=> 27440
Time.now                         #=> 2008-03-08 19:56:19 +0900

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

    rb_secure(2);
    flags = 0;
    if (argc == 0) {
        pid = -1;
    }
    else {
        rb_scan_args(argc, argv, "02", &vpid, &vflags);
        pid = NUM2PIDT(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) {
        rb_last_status_clear();
        return Qnil;
    }
    return PIDT2NUM(pid);
}

wait2(pid=-1, flags=0) => [pid, status] click to toggle source

Waits for a child process to exit (see ::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

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

waitall => [ [pid1,status1], ...] click to toggle source

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)>]]

 
               static VALUE
proc_waitall(void)
{
    VALUE result;
    rb_pid_t pid;
    int status;

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

    for (pid = -1;;) {
#ifdef NO_WAITPID
        pid = wait(&status);
#else
        pid = rb_waitpid(-1, &status, 0);
#endif
        if (pid == -1) {
            if (errno == ECHILD)
                break;
#ifdef NO_WAITPID
            if (errno == EINTR) {
                rb_thread_schedule();
                continue;
            }
#endif
            rb_sys_fail(0);
        }
#ifdef NO_WAITPID
        rb_last_status_set(status, pid);
#endif
        rb_ary_push(result, rb_assoc_new(PIDT2NUM(pid), rb_last_status_get()));
    }
    return result;
}

waitpid(pid=-1, flags=0) => fixnum click to toggle source

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                         #=> 2008-03-08 19:56:16 +0900
waitpid(pid, Process::WNOHANG)   #=> nil
Time.now                         #=> 2008-03-08 19:56:16 +0900
waitpid(pid, 0)                  #=> 27440
Time.now                         #=> 2008-03-08 19:56:19 +0900

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

    rb_secure(2);
    flags = 0;
    if (argc == 0) {
        pid = -1;
    }
    else {
        rb_scan_args(argc, argv, "02", &vpid, &vflags);
        pid = NUM2PIDT(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) {
        rb_last_status_clear();
        return Qnil;
    }
    return PIDT2NUM(pid);
}

waitpid2(pid=-1, flags=0) => [pid, status] click to toggle source

Waits for a child process to exit (see ::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

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

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