newlib-cygwin/newlib/libc/string/strcasecmp.c

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2000-02-18 03:39:52 +08:00
/*
FUNCTION
<<strcasecmp>>---case insensitive character string compare
INDEX
strcasecmp
ANSI_SYNOPSIS
#include <string.h>
int strcasecmp(const char *<[a]>, const char *<[b]>);
TRAD_SYNOPSIS
#include <string.h>
int strcasecmp(<[a]>, <[b]>)
char *<[a]>;
char *<[b]>;
DESCRIPTION
<<strcasecmp>> compares the string at <[a]> to
the string at <[b]> in a case-insensitive manner.
RETURNS
If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
both are converted to upper case), <<strcasecmp>> returns a
number greater than zero. If the two strings match,
<<strcasecmp>> returns zero. If <<*<[a]>>> sorts
lexicographically before <<*<[b]>>>, <<strcasecmp>> returns a
number less than zero.
PORTABILITY
<<strcasecmp>> is in the Berkeley Software Distribution.
<<strcasecmp>> requires no supporting OS subroutines. It uses
tolower() from elsewhere in this library.
QUICKREF
strcasecmp
*/
#include <string.h>
#include <ctype.h>
int
_DEFUN (strcasecmp, (s1, s2),
_CONST char *s1 _AND
_CONST char *s2)
{
while (*s1 != '\0' && tolower(*s1) == tolower(*s2))
{
s1++;
s2++;
}
return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
}