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

61 lines
1.3 KiB
C

/*
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 lowercase), <<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)
{
_CONST unsigned char *ucs1 = (_CONST unsigned char *) s1;
_CONST unsigned char *ucs2 = (_CONST unsigned char *) s2;
int d = 0;
for ( ; ; )
{
_CONST int c1 = tolower(*ucs1++);
_CONST int c2 = tolower(*ucs2++);
if (((d = c1 - c2) != 0) || (c2 == '\0'))
break;
}
return d;
}