NAME
exit —
perform normal program
termination
LIBRARY
library “libc”
SYNOPSIS
#include
<stdlib.h>
void
exit(int
status);
DESCRIPTION
exit()
terminates a process. The status values
EXIT_SUCCESS and EXIT_FAILURE
can be used to indicate successful and unsuccessful termination, respectively.
Before termination it performs the following functions in the order listed:
- Call the functions registered with the atexit(3) function, in the reverse order of their registration.
- Flush all open output streams.
- Close all open streams.
- Unlink all files created with the tmpfile(3) function.
Following this,
exit() calls
_exit(2).
RESTRICTIONS
Standard C guarantees only that the values zero,
EXIT_SUCCESS, and
EXIT_FAILURE produce meaningful results. POSIX
extends this to guarantee that the least significant 8 bits of
status are preserved and returned to the parent via
wait(2). Values outside the supported range 0-255 are
bitwise-truncated; therefore, negative values should not be used.
RETURN VALUES
The exit() function never returns.
SEE ALSO
_exit(2), at_quick_exit(3), atexit(3), intro(3), quick_exit(3), tmpfile(3)
STANDARDS
The exit() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
HISTORY
The exit() function appeared in
Version 1 AT&T UNIX.