freebsd-nq/lib/libc/string/index.3
Simon L. B. Nielsen c9ae54eebb * Merge index(3) and rindex(3) to index(3) since the two functions are
almost identical.
* Merge strchr(3) and strrchr(3) to strchr(3) since the two functions
  are almost identical.
* Make the wording of index(3) and strchr(3) more similar.
* mdoc(7) cleanup.

Submitted by:	SUZUKI Koichi <metal@gc5.so-net.ne.jp>, keramida, myself
PR:		docs/32054
Reviewed by:	ru
Approved by:	ceri (mentor)
2003-07-28 22:50:42 +00:00

107 lines
3.1 KiB
Groff

.\" 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.
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.\" @(#)index.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt INDEX 3
.Os
.Sh NAME
.Nm index , rindex
.Nd locate character in string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In strings.h
.Ft "char *"
.Fn index "const char *s" "int c"
.Ft "char *"
.Fn rindex "const char *s" "int c"
.Sh DESCRIPTION
The
.Fn index
function
locates the first occurrence of
.Fa c
(converted to a
.Vt char )
in the string pointed to by
.Fa s .
The terminating null character is considered part of the string.
.Pp
The
.Fn rindex
function is identical to
.Fn index ,
except it locates the last occurrence of
.Fa c .
.Sh RETURN VALUES
The functions
.Fn index
and
.Fn rindex
return a pointer to the located character, or
.Dv NULL
if the character does not appear in the string.
If
.Fa c
is
.Ql \e0 ,
the functions locate the terminating
.Ql \e0 .
.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 strstr 3 ,
.Xr strtok 3
.Sh HISTORY
The
.Fn index
and
.Fn rindex
functions appeared in
.At v6 .
Their prototypes existed previously in
.Aq Pa string.h
before they were moved to
.Aq Pa strings.h
for
.St -p1003.1-2001
compliance.