FORK(3am)                           GNU Awk Extension Modules                           FORK(3am)



NAME
       fork, wait, waitpid - basic process management

SYNOPSIS
       @load "fork"

       pid = fork()

       ret = waitpid(pid)

       ret = wait();

DESCRIPTION
       The fork extension adds three functions, as follows.

       fork() This  function creates a new process. The return value is the zero in the child and
              the process-id number of the child in the parent, or -1 upon error. In  the  latter
              case,   ERRNO   indicates   the   problem.    In  the  child,  PROCINFO["pid"]  and
              PROCINFO["ppid"] are updated to reflect the correct values.

       waitpid()
              This function takes a numeric argument, which is the process-id to  wait  for.  The
              return value is that of the waitpid(2) system call.

       wait() This  function  waits  for the first child to die.  The return value is that of the
              wait(2) system call.

BUGS
       There is no corresponding exec() function.

       The interfaces could be enhanced to provide more facilities,  including  pulling  out  the
       various bits of the return status.

EXAMPLE
       @load "fork"
       ...
       if ((pid = fork()) == 0)
           print "hello from the child"
       else
           print "hello from the parent"

SEE ALSO
       GAWK:  Effective AWK Programming, filefuncs(3am), fnmatch(3am), inplace(3am), ordchr(3am),
       readdir(3am), readfile(3am), revoutput(3am), rwarray(3am), time(3am).

       fork(2), wait(2), waitpid(2).

AUTHOR
       Arnold Robbins, arnold AT skeeve.com.

COPYING PERMISSIONS
       Copyright © 2012, 2013, Free Software Foundation, Inc.

       Permission is granted to make and distribute verbatim copies of this manual page  provided
       the copyright notice and this permission notice are preserved on all copies.

       Permission  is  granted to copy and distribute modified versions of this manual page under
       the conditions for verbatim copying, provided that the entire resulting  derived  work  is
       distributed under the terms of a permission notice identical to this one.

       Permission is granted to copy and distribute translations of this manual page into another
       language, under the above conditions for modified versions, except  that  this  permission
       notice may be stated in a translation approved by the Foundation.



Free Software Foundation                   Jan 15 2013                                  FORK(3am)