functions save their calling environment in
Each of these functions returns 0.
functions restore the environment saved by their most recent respective
They then return so that program execution continues as if the corresponding
invocation of the
call had just returned the value specified by
instead of 0.
Pairs of calls may be intermixed, i.e., both
combinations may be used in the same program, however, individual
calls may not, e.g. the
may not be passed to
routines may not be called after the routine which called the
All accessible objects have values as of the time
routine was called, except that the values of objects of automatic storage
invocation duration that do not have the
type and have been changed between the
call are indeterminate.
setjmp / longjmp
pairs save and restore the signal mask while
_setjmp / _longjmp
pairs save and restore only the register set and the stack.
sigsetjmp / siglongjmp
pairs save and restore the signal mask if the argument
is non-zero, otherwise only the register set and the stack are saved.