1.\" $OpenBSD: strchr.3,v 1.13 2018/10/01 06:37:37 martijn Exp $ 2.\" 3.\" Copyright (c) 1990, 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Chris Torek and the American National Standards Committee X3, 8.\" on Information Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. 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.Dd $Mdocdate: October 1 2018 $ 35.Dt STRCHR 3 36.Os 37.Sh NAME 38.Nm strchr , 39.Nm index 40.Nd locate first occurrence of a character in a string 41.Sh SYNOPSIS 42.In string.h 43.Ft char * 44.Fn strchr "const char *s" "int c" 45.In strings.h 46.Ft char * 47.Fn index "const char *s" "int c" 48.Sh DESCRIPTION 49The 50.Fn strchr 51function locates the first occurrence of the character 52.Fa c 53.Pq converted to a char 54in the string 55.Fa s . 56The terminating NUL character is considered part of the string. 57If 58.Fa c 59is 60.Ql \e0 , 61.Fn strchr 62locates the terminating 63.Ql \e0 . 64.Pp 65The 66.Fn index 67function is an old synonym for 68.Fn strchr . 69.Sh RETURN VALUES 70The 71.Fn strchr 72function returns a pointer to the located character or 73.Dv NULL 74if the character does not appear in the string. 75.Sh EXAMPLES 76After the following call to 77.Fn strchr , 78.Va p 79will point to the string 80.Qq oobar : 81.Bd -literal -offset indent 82char *p; 83char *s = "foobar"; 84 85p = strchr(s, 'o'); 86.Ed 87.Sh SEE ALSO 88.Xr memchr 3 , 89.Xr strcspn 3 , 90.Xr strpbrk 3 , 91.Xr strrchr 3 , 92.Xr strsep 3 , 93.Xr strspn 3 , 94.Xr strstr 3 , 95.Xr strtok 3 , 96.Xr wcschr 3 97.Sh STANDARDS 98The 99.Fn strchr 100function conforms to 101.St -ansiC . 102.Pp 103The 104.Fn index 105function is deprecated and shouldn't be used in new code. 106.Sh HISTORY 107The 108.Fn index 109function first appeared in 110.At v7 . 111The 112.Fn strchr 113function first appeared in 114.At III 115and was reimplemented for 116.Bx 4.3 Tahoe . 117