longjmp Function

A function that restores the environment saved by setjmp.

Include

<setjmp.h>

Prototype

void longjmp(jmp_buf env, int val);

Arguments

env

variable where environment is stored.

val

value to be returned to setjmp call.

Remarks

The value parameter, val, should be non-zero. If longjmp is invoked from a nested signal handler (that is, invoked as a result of a signal raised during the handling of another signal), the behavior is undefined.

Example

#include <stdio.h>
#include <setjmp.h>
#include <stdlib.h>

jmp_buf jb;

void inner (void)
{
    longjmp(jb, 5);
}
int main (void)
{
  int i;
  if(i = setjmp(jb)) {
    printf("setjmp returned %d\n" i);
    exit(0);
  }
  printf("setjmp returned 0 - good\n");
  printf("calling inner...\n");
  inner();
  printf("inner returned - bad!\n");
}

Example Output

setjmp returned 0 - good
calling inner...