usr/man/man3/setjmp.3

.TH SETJMP 3
.SH NAME
setjmp, longjmp \- non-local goto
.SH SYNOPSIS
.B #include <setjmp.h>
.PP
.B setjmp(env)
.br
.B jmp_buf env;
.PP
.B longjmp(env, val)
.br
.B jmp_buf env;
.SH DESCRIPTION
These routines are useful for dealing with errors
and interrupts encountered in
a low-level subroutine of a program.
.PP
.I Setjmp
saves its stack environment in
.I env
for later use by
.I longjmp.
It returns value 0.
.PP
.I Longjmp
restores the environment saved by the last call of
.IR setjmp .
It then returns in such a way that execution
continues as if the call of
.I setjmp
had just returned the value
.I val
to the function that invoked
.I setjmp,
which must not itself have returned in the interim.
All accessible data have values as of the time
.I longjmp
was called.
.SH "SEE ALSO"
signal(2)