Libc-763.13.tar.gz

[apple/libc.git] / string / strcspn.3

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.\"     @(#)strcspn.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/string/strcspn.3,v 1.9 2007/01/09 00:28:12 imp Exp $
.\"
.Dd June 4, 1993
.Dt STRCSPN 3
.Os
.Sh NAME
.Nm strcspn
.Nd span the complement of a string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft size_t
.Fo strcspn
.Fa "const char *s1"
.Fa "const char *s2"
.Fc
.Sh DESCRIPTION
The
.Fn strcspn
function
spans the initial part of the null-terminated string
.Fa s1 ,
as long as the characters from
.Fa s1
do not occur in string
.Fa s2
(it
spans the
.Em complement
of
.Fa s2 ) .
In other words, it computes the string array index in
.Fa s1
of the first character of
.Fa s1
which is also in
.Fa s2 ,
else the index of the first null character.
.Sh RETURN VALUES
The
.Fn strcspn
function
returns the number of characters spanned.
.Sh SEE ALSO
.Xr memchr 3 ,
.Xr strchr 3 ,
.Xr strpbrk 3 ,
.Xr strrchr 3 ,
.Xr strsep 3 ,
.Xr strspn 3 ,
.Xr strstr 3 ,
.Xr strtok 3
.Sh STANDARDS
The
.Fn strcspn
function
conforms to
.St -isoC .