V10/man/man2/fork.2

Compare this file to the similar file:
Show the results in this format: 

.TH FORK 2
.CT 2 proc_man
.SH NAME
fork \(mi spawn new process
.SH SYNOPSIS
.nf
.B int fork()
.fi
.SH DESCRIPTION
.I Fork
is the only way new processes are created.
The new process's image is a copy of
that of the caller of
.IR fork .
The only distinction is
that the value returned in the old (parent) process
is the process id
of the new (child) process,
while the value returned in the child is 0.
Process ids range from 1 to 30,000.
The process id is used by
.IR wait 
(see
.IR exit (2))
and
.I kill
(see
.IR signal (2)).
.PP
Files open before the
.I fork
are shared, and have a common read-write pointer.
This is the way that
.IR sh (1)
passes standard input and output
files and sets up pipes.
.SH "SEE ALSO"
.IR exit (2),
.IR signal (2), 
.IR sh (1)
.SH DIAGNOSTICS
.BR EAGAIN ,
.BR ENOMEM