[unix-history] / usr / src / lib / libc / stdlib / atexit.3

.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)atexit.3	5.3 (Berkeley) 6/29/91
.\"
.Dd June 29, 1991
.Dt ATEXIT 3
.Os
.Sh NAME
.Nm atexit
.Nd register a function to be called on exit
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Ft int
.Fn atexit "void (*function)(void)"
.Sh DESCRIPTION
The
.Fn atexit
function
registers the given
.Ar function
to be called at program exit, whether via
.Xr exit 3
or via return from the program's
.Em main .
Functions so registered are called in reverse order;
no arguments are passed.
At least 32 functions can always be registered,
and more are allowed as long as sufficient memory can be allocated.
.Sh RETURN VALUES
.Rv -std atexit
.Sh ERRORS
.Bl -tag -width [ENOMEM]
.It Bq Er ENOMEM
No memory was available to add the function to the list.
The existing list of functions is unmodified.
.El
.Sh SEE ALSO
.Xr exit 3
.Sh STANDARDS
The
.Fn atexit
function
conforms to
.St -ansiC .
Commit	Line	Data
4d291433 WJ	1	.\" Copyright (c) 1990, 1991 The Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" This code is derived from software contributed to Berkeley by
	5	.\" Chris Torek and the American National Standards Committee X3,
	6	.\" on Information Processing Systems.
	7	.\"
	8	.\" Redistribution and use in source and binary forms, with or without
	9	.\" modification, are permitted provided that the following conditions
	10	.\" are met:
	11	.\" 1. Redistributions of source code must retain the above copyright
	12	.\" notice, this list of conditions and the following disclaimer.
	13	.\" 2. Redistributions in binary form must reproduce the above copyright
	14	.\" notice, this list of conditions and the following disclaimer in the
	15	.\" documentation and/or other materials provided with the distribution.
	16	.\" 3. All advertising materials mentioning features or use of this software
	17	.\" must display the following acknowledgement:
	18	.\" This product includes software developed by the University of
	19	.\" California, Berkeley and its contributors.
	20	.\" 4. Neither the name of the University nor the names of its contributors
	21	.\" may be used to endorse or promote products derived from this software
	22	.\" without specific prior written permission.
	23	.\"
	24	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	.\" SUCH DAMAGE.
	35	.\"
	36	.\" @(#)atexit.3 5.3 (Berkeley) 6/29/91
	37	.\"
	38	.Dd June 29, 1991
	39	.Dt ATEXIT 3
	40	.Os
	41	.Sh NAME
	42	.Nm atexit
	43	.Nd register a function to be called on exit
	44	.Sh SYNOPSIS
	45	.Fd #include <stdlib.h>
	46	.Ft int
	47	.Fn atexit "void (*function)(void)"
	48	.Sh DESCRIPTION
	49	The
	50	.Fn atexit
	51	function
	52	registers the given
	53	.Ar function
	54	to be called at program exit, whether via
	55	.Xr exit 3
	56	or via return from the program's
	57	.Em main .
	58	Functions so registered are called in reverse order;
	59	no arguments are passed.
	60	At least 32 functions can always be registered,
	61	and more are allowed as long as sufficient memory can be allocated.
	62	.Sh RETURN VALUES
	63	.Rv -std atexit
	64	.Sh ERRORS
65	.Bl -tag -width [ENOMEM]
66	.It Bq Er ENOMEM
67	No memory was available to add the function to the list.
68	The existing list of functions is unmodified.
69	.El
70	.Sh SEE ALSO
71	.Xr exit 3
72	.Sh STANDARDS
73	The
74	.Fn atexit
75	function
76	conforms to
77	.St -ansiC .