minix/lib/libc/gen/setproctitle.3

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.\" $NetBSD: setproctitle.3,v 1.18 2003/07/26 19:24:44 salo Exp $
.\"
.\" Copyright (c) 1994, 1995 Christopher G. Demetriou
.\" All rights reserved.
.\"
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.\" <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
.\"
.Dd April 13, 1994
.Dt SETPROCTITLE 3
.Os
.Sh NAME
.Nm setproctitle
.Nd set process title
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft void
.Fn setproctitle "const char *fmt" "..."
.Sh DESCRIPTION
The
.Fn setproctitle
function sets the invoking process's title.
The process title is set to the last component of the program
name, followed by a colon and the formatted string specified
by
.Va fmt .
If
.Va fmt
is
.Dv NULL ,
the colon and formatted string are omitted.
The length of a process title is limited to 2048 bytes.
.Sh EXAMPLES
Set the process title to the program name, with no further information:
.Bd -literal -offset indent
setproctitle(NULL);
.Ed
.Pp
Set the process title to the program name, an informational string,
and the process id:
.Bd -literal -offset indent
setproctitle("foo! (%d)", getpid());
.Ed
.Sh SEE ALSO
.Xr ps 1 ,
.Xr w 1 ,
.Xr getprogname 3 ,
.Xr printf 3
.Sh HISTORY
The
.Fn setproctitle
function first appeared in
.Nx 1.0 .
.Sh CAVEATS
It is important never to pass a string with user-supplied data as a
format without using
.Ql %s .
An attacker can put format specifiers in the string to mangle your stack,
leading to a possible security hole.
This holds true even if you have built the string
.Dq by hand
using a function like
.Fn snprintf ,
as the resulting string may still contain user-supplied conversion specifiers
for later interpolation by
.Fn setproctitle .
.Pp
Always be sure to use the proper secure idiom:
.Bd -literal -offset indent
setproctitle("%s", string);
.Ed