<HTML
><HEAD
><TITLE
>Process Control Functions</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
REL="HOME"
TITLE="PHP Manual"
HREF="index.html"><LINK
REL="UP"
TITLE="Function Reference"
HREF="funcref.html"><LINK
REL="PREVIOUS"
TITLE="pg_update"
HREF="function.pg-update.html"><LINK
REL="NEXT"
TITLE="pcntl_exec"
HREF="function.pcntl-exec.html"><META
HTTP-EQUIV="Content-type"
CONTENT="text/html; charset=ISO-8859-1"></HEAD
><BODY
CLASS="reference"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>PHP Manual</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="function.pg-update.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="function.pcntl-exec.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="reference"
><A
NAME="ref.pcntl"
></A
><DIV
CLASS="TITLEPAGE"
><H1
CLASS="title"
>LXXXII. Process Control Functions</H1
><DIV
CLASS="PARTINTRO"
><A
NAME="AEN78107"
></A
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.intro"
></A
>Introduction</H1
><P
> Process Control support in PHP implements the Unix style of
process creation, program execution, signal handling and process
termination. Process Control should not be enabled within a
webserver environment and unexpected results may happen if any
Process Control functions are used within a webserver environment.
</P
><P
> This documentation is intended to explain the general usage of
each of the Process Control functions. For detailed information
about Unix process control you are encouraged to consult your
systems documentation including fork(2), waitpid(2) and signal(2)
or a comprehensive reference such as Advanced Programming in the
UNIX Environment by W. Richard Stevens (Addison-Wesley).
</P
><P
> PCNTL now uses ticks as the signal handle callback mechanism, which is
much faster than the previous mechanism. This change follows the same
semantics as using "user ticks". You use the <B
CLASS="function"
>declare()</B
>
statement to specify the locations in your program where callbacks are
allowed to occur. This allows you to minimize the overhead of handling
asynchronous events. In the past, compiling PHP with pcntl enabled would
always incur this overhead, whether or not your script actually used
pcntl.
</P
><P
> There is one adjustment that all pcntl scripts prior to PHP 4.3.0 must
make for them to work which is to either to use
<B
CLASS="function"
>declare()</B
> on a section where you wish to allow
callbacks or to just enable it across the entire script using
the new global syntax of <B
CLASS="function"
>declare()</B
>.
</P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>This extension is not
available on Windows platforms.</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.requirements"
></A
>Requirements</H1
><P
>No external libraries are needed to build this extension.</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.installation"
></A
>Installation</H1
><P
> Process Control support in PHP is not enabled by default.
You have to compile the CGI or CLI version of PHP with
<TT
CLASS="option"
>--enable-pcntl</TT
> configuration
option when compiling PHP to enable Process Control support.
</P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>
Currently, this module will not function on non-Unix platforms
(Windows).
</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.configuration"
></A
>Runtime Configuration</H1
><P
>This extension has no configuration directives defined in <TT
CLASS="filename"
>php.ini</TT
>.</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.resources"
></A
>Resource Types</H1
><P
>This extension has no resource types defined.</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.constants"
></A
>Predefined Constants</H1
><P
>
The following list of signals are supported by the Process Control
functions. Please see your systems signal(7) man page for details
of the default behavior of these signals.
</P
><P
></P
><DIV
CLASS="variablelist"
><DL
><DT
><TT
CLASS="constant"
><B
>WNOHANG</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>WUNTRACED</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIG_IGN</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIG_DFL</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIG_ERR</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGHUP</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGINT</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGQUIT</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGILL</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGTRAP</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGABRT</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGIOT</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGBUS</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGFPE</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGKILL</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGUSR1</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGSEGV</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGUSR2</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGPIPE</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGALRM</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGTERM</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGSTKFLT</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGCLD</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGCHLD</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGCONT</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGSTOP</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGTSTP</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGTTIN</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGTTOU</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGURG</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGXCPU</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGXFSZ</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGVTALRM</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGPROF</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGWINCH</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGPOLL</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGIO</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGPWR</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGSYS</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>SIGBABY</B
></TT
>
(<A
HREF="language.types.integer.html"
>integer</A
>)</DT
><DD
><P
>
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.example"
></A
>Examples</H1
><P
> This example forks off a daemon process with a signal handler.
</P
><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN78382"
></A
><P
><B
>Example 1. Process Control Example</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
CELLPADDING="5"
><TR
><TD
><PRE
CLASS="php"
><?php
declare(ticks=1);
$pid = pcntl_fork();
if ($pid == -1) {
die("could not fork");
} else if ($pid) {
exit(); // we are the parent
} else {
// we are the child
}
// detatch from the controlling terminal
if (!posix_setsid()) {
die("could not detach from terminal");
}
// setup signal handlers
pcntl_signal(SIGTERM, "sig_handler");
pcntl_signal(SIGHUP, "sig_handler");
// loop forever performing tasks
while(1) {
// do something interesting here
}
function sig_handler($signo) {
switch($signo) {
case SIGTERM:
// handle shutdown tasks
exit;
break;
case SIGHUP:
// handle restart tasks
break;
default:
// handle all other signals
}
}
?></PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="pcntl.seealso"
></A
>See Also</H1
><P
> A look at the section about
<A
HREF="ref.posix.html"
>POSIX functions</A
>
may be useful.
</P
></DIV
></DIV
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="function.pcntl-exec.html"
>pcntl_exec</A
> --
Executes specified program in current process space
</DT
><DT
><A
HREF="function.pcntl-fork.html"
>pcntl_fork</A
> -- Forks the currently running process</DT
><DT
><A
HREF="function.pcntl-signal.html"
>pcntl_signal</A
> -- Installs a signal handler</DT
><DT
><A
HREF="function.pcntl-waitpid.html"
>pcntl_waitpid</A
> -- Waits on or returns the status of a forked child</DT
><DT
><A
HREF="function.pcntl-wexitstatus.html"
>pcntl_wexitstatus</A
> --
Returns the return code of a terminated child
</DT
><DT
><A
HREF="function.pcntl-wifexited.html"
>pcntl_wifexited</A
> --
Returns <TT
CLASS="constant"
><B
>TRUE</B
></TT
> if status code represents a successful exit
</DT
><DT
><A
HREF="function.pcntl-wifsignaled.html"
>pcntl_wifsignaled</A
> --
Returns <TT
CLASS="constant"
><B
>TRUE</B
></TT
> if status code represents a termination due to a
signal
</DT
><DT
><A
HREF="function.pcntl-wifstopped.html"
>pcntl_wifstopped</A
> --
Returns <TT
CLASS="constant"
><B
>TRUE</B
></TT
> if child process is currently stopped
</DT
><DT
><A
HREF="function.pcntl-wstopsig.html"
>pcntl_wstopsig</A
> --
Returns the signal which caused the child to stop
</DT
><DT
><A
HREF="function.pcntl-wtermsig.html"
>pcntl_wtermsig</A
> --
Returns the signal which caused the child to terminate
</DT
></DL
></DIV
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="function.pg-update.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="function.pcntl-exec.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>pg_update</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="funcref.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>pcntl_exec</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
distrib
>
Mandriva
>
9.1
>
ppc
>
media
>
main
>
by-pkgid
>
0afeee9cca140e167a996902b9a677c5
>
files
>
3124
