setjmp

Saves the current state of the program.

Syntax

int setjmp(  
   jmp_buf env   
);  

Parameters

env
Variable in which environment is stored.

Return Value

Returns 0 after saving the stack environment. If setjmp returns as a result of a longjmp call, it returns the value argument of longjmp, or if the value argument of longjmp is 0, setjmp returns 1. There is no error return.

Remarks

The setjmp function saves a stack environment, which you can subsequently restore, using longjmp. When used together, setjmp and longjmp provide a way to execute a non-local goto. They are typically used to pass execution control to error-handling or recovery code in a previously called routine without using the normal calling or return conventions.

A call to setjmp saves the current stack environment in env. A subsequent call to longjmp restores the saved environment and returns control to the point just after the corresponding setjmp call. All variables (except register variables) accessible to the routine receiving control contain the values they had when longjmp was called.

It is not possible to use setjmp to jump from native to managed code.

Note setjmp and longjmp do not support C++ object semantics. In C++ programs, use the C++ exception-handling mechanism.

For more information, see Using setjmp and longjmp.

Requirements

Routine Required header
setjmp <setjmp.h>

For additional compatibility information, see Compatibility in the Introduction.

Example

See the example for _fpreset.

See Also

Process and Environment Control
longjmp
_setjmp3