Libc-594.9.5.tar.gz

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

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.\"     @(#)strcasecmp.3	8.1 (Berkeley) 6/9/93
.\" $FreeBSD: src/lib/libc/string/strcasecmp.3,v 1.11 2003/09/08 19:57:15 ru Exp $
.\"
.Dd June 9, 1993
.Dt STRCASECMP 3
.Os
.Sh NAME
.Nm strcasecmp ,
.Nm strcasecmp_l ,
.Nm strncasecmp ,
.Nm strncasecmp_l
.Nd compare strings, ignoring case
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In strings.h
.Ft int
.Fo strcasecmp
.Fa "const char *s1"
.Fa "const char *s2"
.Fc
.Ft int
.Fo strncasecmp
.Fa "const char *s1"
.Fa "const char *s2"
.Fa "size_t n"
.Fc
.In strings.h
.In xlocale.h
.Ft int
.Fo strcasecmp_l
.Fa "const char *s1"
.Fa "const char *s2"
.Fa "locale_t loc"
.Fc
.Ft int
.Fo strncasecmp_l
.Fa "const char *s1"
.Fa "const char *s2"
.Fa "size_t n"
.Fa "locale_t loc"
.Fc
.Sh DESCRIPTION
The
.Fn strcasecmp
and
.Fn strncasecmp
functions
compare the null-terminated strings
.Fa s1
and
.Fa s2 .
.Pp
The
.Fn strncasecmp
compares at most
.Fa n
characters.
.Pp
Although the
.Fn strcasecmp
and
.Fn strncasecmp
functions use the current locale, the
.Fn strcasecmp_l
and
.Fn strncasecmp_l
functions may be passed locales directly. See
.Xr xlocale 3
for more information.
.Sh RETURN VALUES
The
.Fn strcasecmp
and
.Fn strncasecmp
return an integer greater than, equal to, or less than 0,
according as
.Fa s1
is lexicographically greater than, equal to, or less than
.Fa s2
after translation of each corresponding character to lower-case.
The strings themselves are not modified.
The comparison is done using unsigned characters, so that
.Sq Li \e200
is greater than
.Ql \e0 .
.Sh SEE ALSO
.Xr bcmp 3 ,
.Xr memcmp 3 ,
.Xr strcmp 3 ,
.Xr strcoll 3 ,
.Xr strxfrm 3 ,
.Xr tolower 3 ,
.Xr xlocale 3
.Sh HISTORY
The
.Fn strcasecmp
and
.Fn strncasecmp
functions first appeared in
.Bx 4.4 .
Their prototypes existed previously in
.In string.h
before they were moved to
.In strings.h
for
.St -p1003.1-2001
compliance.