term% cat index.txt EXITS(2) System Calls Manual EXITS(2)
NAME
exits, _exits, atexit, atexitdont, terminate - terminate process,
process cleanup
SYNOPSIS
#include <u.h>
#include <libc.h>
void _exits(char *msg)
void exits(char *msg)
int atexit(void(*)(void))
void atexitdont(void(*)(void))
DESCRIPTION
Exits is the conventional way to terminate a process. _Exits is the
underlying system call. They can never return.
Msg conventionally includes a brief (maximum length ERRLEN) explanation
of the reason for exiting, or a null pointer or empty string to indi‐
cate normal termination. The string is passed to the parent process,
prefixed by the name and process id of the exiting process, when the
parent does a wait(2).
Before calling _exits with msg as an argument, exits calls in reverse
order all the functions recorded by atexit.
Atexit records fn as a function to be called by exits. It returns zero
if it failed, nonzero otherwise. A typical use is to register a
cleanup routine for an I/O package. To simplify programs that fork or
share memory, exits only calls those atexit-registered functions that
were registered by the same process as that calling exits.
Calling atexit twice (or more) with the same function argument causes
exits to invoke the function twice (or more).
There is a limit to the number of exit functions that will be recorded;
atexit returns 0 if that limit has been reached.
Atexitdont cancels a previous registration of an exit function.
SOURCE
/sys/src/libc/port/atexit.c
SEE ALSO
fork(2), wait(2)
EXITS(2)