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. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)index.3 8.1 (Berkeley) 6/4/93 35.\" $FreeBSD$ 36.\" 37.Dd June 4, 1993 38.Dt INDEX 3 39.Os 40.Sh NAME 41.Nm index 42.Nd locate character in string 43.Sh SYNOPSIS 44.Fd #include <string.h> 45.Ft char * 46.Fn index "const char *s" "int c" 47.Sh DESCRIPTION 48The 49.Fn index 50function 51locates the first character matching 52.Fa c 53(converted to a 54.Em char ) 55in the null-terminated string 56.Fa s . 57.Sh RETURN VALUES 58A pointer to the character is returned if it is found; otherwise 59.Dv NULL 60is returned. 61If 62.Fa c 63is '\e0', 64.Fn index 65locates the terminating '\e0'. 66.Sh SEE ALSO 67.Xr memchr 3 , 68.Xr rindex 3 , 69.Xr strchr 3 , 70.Xr strcspn 3 , 71.Xr strpbrk 3 , 72.Xr strrchr 3 , 73.Xr strsep 3 , 74.Xr strspn 3 , 75.Xr strstr 3 , 76.Xr strtok 3 77.Sh HISTORY 78A 79.Fn index 80function appeared in 81.At v6 . 82