Extended maintenance of Ruby versions 1.8.7 and 1.9.2 ended on July 31, 2014. Read more

In Files

  • process.c

Process

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

Public Class Methods

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(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 */
}
            
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. 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)

 
               static VALUE
proc_detach(VALUE obj, VALUE pid)
{
    rb_secure(2);
    return rb_detach_process(NUM2INT(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(obj)
    VALUE obj;
{
    int egid = getegid();

    return INT2FIX(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(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;
}
            
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(obj)
    VALUE obj;
{
    int euid = geteuid();
    return INT2FIX(euid);
}
            
euid= integer click to toggle source

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;
}
            
exec(command [, arg, ...]) click to toggle source

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
 
               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 */
}
            
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(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 */
}
            
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(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 */
}
            
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(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

    before_exec();
    pid = fork();
    after_exec();

    switch (pid) {
      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
}
            
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(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
}
            
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()
{
#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
}
            
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(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
}
            
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: such as Process::RLIMIT_CORE, Process::RLIMIT_CPU, etc. 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(NUM2INT(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(obj)
    VALUE obj;
{
    int gid = getgid();
    return INT2FIX(gid);
}
            
gid= fixnum => fixnum click to toggle source

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);
}
            
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, INT2NUM(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(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
}
            
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(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
}
            
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(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);
}
            
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(obj)
    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()
{
    rb_secure(2);
    return INT2FIX(getpid());
}
            
ppid => fixnum click to toggle source

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
 
               static VALUE
get_ppid()
{
    rb_secure(2);
#ifdef _WIN32
    return INT2FIX(0);
#else
    return INT2FIX(getppid());
#endif
}
            
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(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
}
            
setpgrp => 0 click to toggle source

Equivalent to setpgid(0,0). 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);
}
            
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(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
}
            
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. 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.

 
               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
}
            
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()
{
#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
}
            
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(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
}
            
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(obj)
    VALUE obj;
{
    int uid = getuid();
    return INT2FIX(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(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);
}
            
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                         #=> 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);
}
            
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(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);
}
            
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()
{
    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;
}
            
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                         #=> 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);
}
            
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(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);
}
            

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