1.\" $NetBSD: getprogname.3,v 1.3 2002/02/07 07:00:13 ross Exp $ 2.\" 3.\" Copyright (c) 2001 Christopher G. Demetriou 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed for the 17.\" NetBSD Project. See http://www.netbsd.org/ for 18.\" information about NetBSD. 19.\" 4. The name of the author may not be used to endorse or promote products 20.\" derived from this software without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32.\" 33.\" <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>> 34.\" 35.Dd February 11, 2001 36.Dt GETPROGNAME 3 37.Os 38.Sh NAME 39.Nm getprogname , 40.Nm setprogname 41.Nd get/set the name of the current program 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]stdlib.h\*[Gt] 46.Ft const char * 47.Fn getprogname "void" 48.Ft void 49.Fn setprogname "const char *name" 50.Sh DESCRIPTION 51These utility functions get and set the current program's name 52as used by various error-reporting functions. 53.Pp 54.Fn getprogname 55returns the name of the current program. 56This function is typically useful when generating error messages 57or other diagnostic output. If the program name has not been 58set, 59.Fn getprogname 60will return 61.Dv NULL . 62.Pp 63.Fn setprogname 64sets the name of the current program to be the last pathname 65component of the 66.Fa name 67argument. It should be invoked at the start of the program, using the 68.Fa argv[0] 69passed into the program's 70.Fn main 71function. A pointer into the string pointed to by the 72.Fa name 73argument is kept as the program name. Therefore, the string pointed 74to by 75.Fa name 76should not be modified during the rest of the program's operation. 77.Pp 78A program's name can only be set once, and in 79.Nx 80that is actually 81done by program start-up code that is run before 82.Fn main 83is called. Therefore, in 84.Nx , 85calling 86.Fn setprogname 87from 88.Fn main 89has no effect. However, it does 90serve to increase the portability of the program: 91on other operating systems, 92.Fn getprogname 93and 94.Fn setprogname 95may be implemented by a portability library, and a call to 96.Fn setprogname 97allows that library to know the program name without 98modifications to that system's program start-up code. 99.Sh SEE ALSO 100.Xr err 3 , 101.Xr setproctitle 3 102.Sh HISTORY 103The 104.Nm getprogname 105and 106.Nm setprogname 107function calls appeared in 108.Nx 1.6 . 109