1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek. 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)index.3 8.1 (Berkeley) 6/4/93 31.\" $NetBSD: index.3,v 1.15 2012/05/05 21:18:43 dholland Exp $ 32.\" 33.Dd May 5, 2012 34.Dt INDEX 3 35.Os 36.Sh NAME 37.Nm index 38.Nd locate character in string 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In strings.h 43.Ft char * 44.Fn index "const char *s" "int c" 45.Sh DESCRIPTION 46The 47.Fn index 48function 49locates the first character matching 50.Fa c 51(converted to a 52.Em char ) 53in the nul-terminated string 54.Fa s . 55.Pp 56This function is obsolete. 57The equivalent function 58.Xr strchr 3 59should be used instead. 60.Sh RETURN VALUES 61A pointer to the character is returned if it is found; otherwise 62.Dv NULL 63is returned. 64If 65.Fa c 66is '\e0', 67.Fn index 68locates the terminating '\e0'. 69.Sh SEE ALSO 70.Xr memchr 3 , 71.Xr rindex 3 , 72.Xr strchr 3 , 73.Xr strcspn 3 , 74.Xr strpbrk 3 , 75.Xr strrchr 3 , 76.Xr strsep 3 , 77.Xr strspn 3 , 78.Xr strstr 3 , 79.Xr strtok 3 80.Sh STANDARDS 81The 82.Fn index 83function conforms to 84.St -p1003.1-2001 . 85The 86.St -p1003.1-2004 87revision marked it as legacy and recommended the use of 88.Xr strchr 3 89instead. 90The 91.St -p1003.1-2008 92revision removed 93.Fn index 94from the specification. 95.Sh HISTORY 96An 97.Fn index 98function appeared in 99.At v6 . 100