vfork
Hurricane Electric Internet Services
NAME
fork, vfork - create a child process
SYNOPSIS
#include <unistd.h>
pid_t fork(void);
pid_t vfork(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 pend-
ing 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 execution. 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.
BUGS
Under Linux, vfork is merely an alias for fork.
fork does never return the error ENOMEM.
CONFORMING TO
SVID, AT&T, POSIX, X/OPEN, BSD 4.3
SEE ALSO
clone(2), execve(2), wait(2)
Hurricane Electric Internet Services
Copyright (C) 1998
Hurricane Electric.
All Rights Reserved.