1.\" $OpenBSD: setproctitle.3,v 1.13 2001/01/26 06:38:23 aaron Exp $ 2.\" 3.\" Copyright (c) 1994, 1995 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 by Christopher G. Demetriou 17.\" for the NetBSD Project. 18.\" 3. 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.Dd April 13, 1994 33.Dt SETPROCTITLE 3 34.Os 35.Sh NAME 36.Nm setproctitle 37.Nd set process title 38.Sh SYNOPSIS 39.Fd #include <stdlib.h> 40.Ft void 41.Fn setproctitle "const char *fmt" "..." 42.Sh DESCRIPTION 43The 44.Fn setproctitle 45function sets the invoking process's title. 46The process title is set to the last component of the program 47name, followed by a colon, a single space, and the formatted string specified 48by 49.Fa fmt . 50If 51.Fa fmt 52is 53.Dv NULL , 54the colon and formatted string are omitted. 55The length of a process title is limited to 2048 bytes. 56.Sh EXAMPLES 57Set the process title to the program name, with no further information: 58.Bd -literal -offset indent 59setproctitle(NULL); 60.Ed 61.Pp 62Set the process title to the program name, an informational string, 63and the process ID: 64.Bd -literal -offset indent 65setproctitle("foo! (%d)", getpid()); 66.Ed 67.Sh SEE ALSO 68.Xr ps 1 , 69.Xr w 1 , 70.Xr printf 3 71.Sh HISTORY 72The 73.Fn setproctitle 74function first appeared in 75.Nx 0.9a . 76.Sh CAVEATS 77It is important to never pass a string with user-supplied data as a 78format without using 79.Ql %s . 80An attacker can put format specifiers in the string to mangle your stack, 81leading to a possible security hole. 82This holds true even if you have built the string 83.Dq by hand 84using a function like 85.Fn snprintf , 86as the resulting string may still contain user-supplied conversion specifiers 87for later interpolation by 88.Fn setproctitle . 89.Pp 90Be sure to always use the proper secure idiom: 91.Bd -literal -offset indent 92setproctitle("%s", string); 93.Ed 94