atexit()
Register functions to be called during normal program termination
Synopsis:
#include <stdlib.h>
int atexit( register void (*func)(void) );
Arguments:
- func
- A pointer to the function you want to be called when the program
terminates normally.
This function has no arguments and doesn't return a value; its prototype
should be:
void func( void );
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The atexit() function registers a function to be called when the program terminates normally. If you register more than one function with atexit(), they're executed in a last-in, first-out order. Normal termination occurs either by a call to exit() or a return from main().
You can register a total of 32 functions with atexit().
The functions registered with atexit() aren't called when the
program terminates with a call to
_exit()
.
Returns:
0 for success, or nonzero if an error occurs.
Examples:
#include <stdio.h> #include <stdlib.h> void func1( void ) { printf( "last.\n" ); } void func2( void ) { printf( "this " ); } void func3( void ) { printf( "Do " ); } int main( void ) { atexit( func1 ); atexit( func2 ); atexit( func3 ); printf( "Do this first.\n" ); return EXIT_SUCCESS; }
produces the output:
Do this first. Do this last.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |