mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
148 lines
4.0 KiB
Groff
148 lines
4.0 KiB
Groff
.\" Copyright (c) 2001 Mike Barcroft <mike@FreeBSD.org>
|
|
.\" 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.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)strstr.3 8.1 (Berkeley) 6/4/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd October 11, 2001
|
|
.Dt STRSTR 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm strstr , strcasestr , strnstr
|
|
.Nd locate a substring in a string
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In string.h
|
|
.Ft char *
|
|
.Fn strstr "const char *big" "const char *little"
|
|
.Ft char *
|
|
.Fn strcasestr "const char *big" "const char *little"
|
|
.Ft char *
|
|
.Fn strnstr "const char *big" "const char *little" "size_t len"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn strstr
|
|
function
|
|
locates the first occurrence of the null-terminated string
|
|
.Fa little
|
|
in the null-terminated string
|
|
.Fa big .
|
|
.Pp
|
|
The
|
|
.Fn strcasestr
|
|
function is similar to
|
|
.Fn strstr ,
|
|
but ignores the case of both strings.
|
|
.Pp
|
|
The
|
|
.Fn strnstr
|
|
function
|
|
locates the first occurrence of the null-terminated string
|
|
.Fa little
|
|
in the string
|
|
.Fa big ,
|
|
where not more than
|
|
.Fa len
|
|
characters are searched.
|
|
Characters that appear after a
|
|
.Ql \e0
|
|
character are not searched.
|
|
Since the
|
|
.Fn strnstr
|
|
function is a
|
|
.Fx
|
|
specific API, it should only be used when portability is not a concern.
|
|
.Sh RETURN VALUES
|
|
If
|
|
.Fa little
|
|
is an empty string,
|
|
.Fa big
|
|
is returned;
|
|
if
|
|
.Fa little
|
|
occurs nowhere in
|
|
.Fa big ,
|
|
.Dv NULL
|
|
is returned;
|
|
otherwise a pointer to the first character of the first occurrence of
|
|
.Fa little
|
|
is returned.
|
|
.Sh EXAMPLES
|
|
The following sets the pointer
|
|
.Va ptr
|
|
to the
|
|
.Qq Li Bar Baz
|
|
portion of
|
|
.Va largestring :
|
|
.Bd -literal -offset indent
|
|
const char *largestring = "Foo Bar Baz";
|
|
const char *smallstring = "Bar";
|
|
char *ptr;
|
|
|
|
ptr = strstr(largestring, smallstring);
|
|
.Ed
|
|
.Pp
|
|
The following sets the pointer
|
|
.Va ptr
|
|
to
|
|
.Dv NULL ,
|
|
because only the first 4 characters of
|
|
.Va largestring
|
|
are searched:
|
|
.Bd -literal -offset indent
|
|
const char *largestring = "Foo Bar Baz";
|
|
const char *smallstring = "Bar";
|
|
char *ptr;
|
|
|
|
ptr = strnstr(largestring, smallstring, 4);
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr memchr 3 ,
|
|
.Xr strchr 3 ,
|
|
.Xr strcspn 3 ,
|
|
.Xr strpbrk 3 ,
|
|
.Xr strrchr 3 ,
|
|
.Xr strsep 3 ,
|
|
.Xr strspn 3 ,
|
|
.Xr strtok 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn strstr
|
|
function
|
|
conforms to
|
|
.St -isoC .
|