freebsd-dev/lib/libc/string/strchr.3

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.\" Copyright (c) 1990, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" notice, this list of conditions and the following disclaimer in the
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
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.\" @(#)strchr.3 8.2 (Berkeley) 4/19/94
1999-08-28 00:22:10 +00:00
.\" $FreeBSD$
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.\"
.Dd February 13, 2013
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.Dt STRCHR 3
.Os
.Sh NAME
.Nm strchr , strrchr , strchrnul
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.Nd locate character in string
.Sh LIBRARY
.Lb libc
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.Sh SYNOPSIS
.In string.h
.Ft "char *"
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.Fn strchr "const char *s" "int c"
.Ft "char *"
.Fn strrchr "const char *s" "int c"
.Ft "char *"
.Fn strchrnul "const char *s" "int c"
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.Sh DESCRIPTION
The
.Fn strchr
function locates the first occurrence of
.Fa c
(converted to a
.Vt char )
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in the string pointed to by
.Fa s .
The terminating null character is considered part of the string;
therefore if
.Fa c
is
.Ql \e0 ,
the functions locate the terminating
.Ql \e0 .
.Pp
The
.Fn strrchr
function is identical to
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.Fn strchr
except it locates the last occurrence of
.Fa c .
.Pp
The
.Fn strchrnul
function is identical to
.Fn strchr
except that if
.Fa c
is not found in
.Fa s
a pointer to the terminating
.Ql \e0
is returned.
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.Sh RETURN VALUES
The functions
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.Fn strchr
and
.Fn strrchr
return a pointer to the located character, or
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.Dv NULL
if the character does not appear in the string.
.Pp
.Fn strchrnul
returns a pointer to the terminating
.Ql \e0
if the character does not appear in the string.
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.Sh SEE ALSO
.Xr memchr 3 ,
.Xr memmem 3 ,
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.Xr strcspn 3 ,
.Xr strpbrk 3 ,
.Xr strsep 3 ,
.Xr strspn 3 ,
.Xr strstr 3 ,
.Xr strtok 3 ,
.Xr wcschr 3
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.Sh STANDARDS
The functions
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.Fn strchr
and
.Fn strrchr
conform to
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.St -isoC .
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The function
.Fn strchrnul
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is a
.Tn GNU
extension.
.Sh HISTORY
The
.Fn strchrnul
function first appeared in glibc 2.1.1 and was added in
.Fx 10.0 .