[apple/libc.git] / gen / getprogname.3

.\"
.\" Copyright (c) 2001 Christopher G. Demetriou
.\" All rights reserved.
.\"
.\" 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 for the
.\"          NetBSD Project.  See http://www.netbsd.org/ for
.\"          information about NetBSD.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
.\"
.\" $FreeBSD: src/lib/libc/gen/getprogname.3,v 1.5 2001/10/01 16:08:51 ru Exp $
.\"
.Dd May 1, 2001
.Dt GETPROGNAME 3
.Os
.Sh NAME
.Nm getprogname ,
.Nm setprogname
.Nd get or set the program name
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft const char *
.Fn getprogname "void"
.Ft void
.Fn setprogname "const char *progname"
.Sh DESCRIPTION
The
.Fn getprogname
and
.Fn setprogname
functions manipulate the name of the current program.
They are used by error-reporting routines to produce
consistent output.
.Pp
The
.Fn getprogname
function returns the name of the program.
If the name has not been set yet, it will return
.Dv NULL .
.Pp
The
.Fn setprogname
function sets the name of the program to be the last component of the
.Fa progname
argument.
Since a pointer to the given string is kept as the program name,
it should not be modified for the rest of the program's lifetime.
.Pp
In
.Fx ,
the name of the program is set by the start-up code that is run before
.Fn main ;
thus,
running
.Fn setprogname
is not necessary.
Programs that desire maximum portability should still call it;
on another operating system,
these functions may be implemented in a portability library.
Calling
.Fn setprogname
allows the aforementioned library to learn the program name without
modifications to the start-up code.
.Sh SEE ALSO
.Xr err 3
.Sh HISTORY
These functions first appeared in
.Nx 1.6 ,
and made their way into
.Fx 4.4 .
Commit	Line	Data
224c7076 A	1	.\"
	2	.\" Copyright (c) 2001 Christopher G. Demetriou
	3	.\" All rights reserved.
	4	.\"
	5	.\" Redistribution and use in source and binary forms, with or without
	6	.\" modification, are permitted provided that the following conditions
	7	.\" are met:
	8	.\" 1. Redistributions of source code must retain the above copyright
	9	.\" notice, this list of conditions and the following disclaimer.
	10	.\" 2. Redistributions in binary form must reproduce the above copyright
	11	.\" notice, this list of conditions and the following disclaimer in the
	12	.\" documentation and/or other materials provided with the distribution.
	13	.\" 3. All advertising materials mentioning features or use of this software
	14	.\" must display the following acknowledgement:
	15	.\" This product includes software developed for the
	16	.\" NetBSD Project. See http://www.netbsd.org/ for
	17	.\" information about NetBSD.
	18	.\" 4. The name of the author may not be used to endorse or promote products
	19	.\" derived from this software without specific prior written permission.
	20	.\"
	21	.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	22	.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	23	.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	24	.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	25	.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	26	.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	27	.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	28	.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	29	.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	30	.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	31	.\"
	32	.\" $FreeBSD: src/lib/libc/gen/getprogname.3,v 1.5 2001/10/01 16:08:51 ru Exp $
	33	.\"
	34	.Dd May 1, 2001
	35	.Dt GETPROGNAME 3
	36	.Os
	37	.Sh NAME
	38	.Nm getprogname ,
	39	.Nm setprogname
	40	.Nd get or set the program name
	41	.Sh LIBRARY
	42	.Lb libc
	43	.Sh SYNOPSIS
	44	.In stdlib.h
	45	.Ft const char *
	46	.Fn getprogname "void"
	47	.Ft void
	48	.Fn setprogname "const char *progname"
	49	.Sh DESCRIPTION
	50	The
	51	.Fn getprogname
	52	and
	53	.Fn setprogname
	54	functions manipulate the name of the current program.
	55	They are used by error-reporting routines to produce
	56	consistent output.
	57	.Pp
	58	The
	59	.Fn getprogname
	60	function returns the name of the program.
	61	If the name has not been set yet, it will return
	62	.Dv NULL .
	63	.Pp
	64	The
65	.Fn setprogname
66	function sets the name of the program to be the last component of the
67	.Fa progname
68	argument.
69	Since a pointer to the given string is kept as the program name,
70	it should not be modified for the rest of the program's lifetime.
71	.Pp
72	In
73	.Fx ,
74	the name of the program is set by the start-up code that is run before
75	.Fn main ;
76	thus,
77	running
78	.Fn setprogname
79	is not necessary.
80	Programs that desire maximum portability should still call it;
81	on another operating system,
82	these functions may be implemented in a portability library.
83	Calling
84	.Fn setprogname
85	allows the aforementioned library to learn the program name without
86	modifications to the start-up code.
87	.Sh SEE ALSO
88	.Xr err 3
89	.Sh HISTORY
90	These functions first appeared in
91	.Nx 1.6 ,
92	and made their way into
93	.Fx 4.4 .