The Process
module is a collection of methods used to
manipulate processes.
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 */ }
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)); }
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.
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
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.
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; }
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 */ }
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 */ }
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 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
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 }
static VALUE proc_getpgrp() { int pgrp; 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
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 ::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 }
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.
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]
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]
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]
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!
VALUE rb_f_kill(argc, argv) int argc; VALUE *argv; { int negative = 0; int sig; int i; 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
static VALUE proc_getmaxgroups(obj) VALUE obj; { return INT2FIX(maxgroups); }
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
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
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.
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.
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
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.
core size (bytes) (SUSv3)
CPU time (seconds) (SUSv3)
data segment (bytes) (SUSv3)
file size (bytes) (SUSv3)
file descriptors (number) (SUSv3)
stack size (bytes) (SUSv3)
total available memory (bytes) (SUSv3, NetBSD, FreeBSD, OpenBSD but 4.4BSD-Lite)
total size for mlock(2) (bytes) (4.4BSD, GNU/Linux)
number of processes for the user (number) (4.4BSD, GNU/Linux)
resident memory size (bytes) (4.2BSD, GNU/Linux)
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 }
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]
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
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.
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:
Waits for the child whose process ID equals pid.
Waits for any child whose process group ID equals that of the calling process.
Waits for any child process (the default if no pid is given).
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); }
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); }
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; }
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:
Waits for the child whose process ID equals pid.
Waits for any child whose process group ID equals that of the calling process.
Waits for any child process (the default if no pid is given).
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); }
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); }