SETJMP

Section: Library functions (3)
Updated: 1997-03-02
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NAME

setjmp, sigsetjmp - save stack context for non-local goto  

SYNOPSIS

#include <setjmp.h>

int setjmp(jmp_buf env);
int sigsetjmp(sigjmp_buf env, int savesigs);
 

DESCRIPTION

setjmp() and longjmp() are useful for dealing with errors and interrupts encountered in a low-level subroutine of a program. setjmp() saves the stack context/environment in env for later use by longjmp(). The stack context will be invalidated if the function which called setjmp() returns. sigsetjmp() is similar to setjmp(). If savesigs is non-zero, the set of blocked signals is saved in env and will be restored if a siglongjmp() is later performed with this env.  

RETURN VALUE

setjmp() and sigsetjmp() return 0 if returning directly, and non-zero when returning from longjmp() using the saved context.  

CONFORMING TO

POSIX.1-2001, C99  

NOTES

POSIX does not specify whether setjmp() will save the signal context. (In System V it will not. In 4.3BSD it will, and there is a function _setjmp that will not.) If you want to save signal masks, use sigsetjmp(). setjmp() and sigsetjmp() make programs hard to understand and maintain. If possible an alternative should be used.  

SEE ALSO

longjmp(3), siglongjmp(3)


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
CONFORMING TO
NOTES
SEE ALSO

linux.jgfs.net manual pages