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FORK(2)			   Linux Programmer's Manual		       FORK(2)

NAME
       fork - create a child process

SYNOPSIS
       #include	<sys/types.h>
       #include	<unistd.h>

       pid_t fork(void);

DESCRIPTION
       fork  creates a child process that differs from the parent process only
       in its PID and PPID, and	in the fact that resource utilizations are set
       to 0.  File locks and pending signals are not inherited.

       Under Linux, fork is implemented	using copy-on-write pages, so the only
       penalty incurred	by fork	is the time and	memory required	 to  duplicate
       the parent's page tables, and to	create a unique	task structure for the
       child.

RETURN VALUE
       On success, the PID of the child	process	is returned  in	 the  parent's
       thread  of execution, and a 0 is	returned in the	child's	thread of exe-
       cution.	On failure, a -1 will be returned in the parent's context,  no
       child process will be created, and errno	will be	set appropriately.

ERRORS
       EAGAIN fork cannot allocate sufficient memory to	copy the parent's page
	      tables and allocate a task structure for the child.

       ENOMEM fork failed to allocate the necessary kernel structures  because
	      memory is	tight.

CONFORMING TO
       The fork	call conforms to SVr4, SVID, POSIX, X/OPEN, BSD	4.3.

SEE ALSO
       clone(2), execve(2), vfork(2), wait(2)

Linux 1.2.9			  1995-06-10			       FORK(2)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO

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