1 /* Copyright (c) 2016 Corinna Vinschen <corinna@vinschen.de> */
2 /*
3 FUNCTION
4 <<strcasecmp_l>>---case-insensitive character string compare
5
6 INDEX
7 strcasecmp_l
8
9 SYNOPSIS
10 #include <strings.h>
11 int strcasecmp_l(const char *<[a]>, const char *<[b]>,
12 locale_t <[locale]>);
13
14 DESCRIPTION
15 <<strcasecmp_l>> compares the string at <[a]> to
16 the string at <[b]> in a case-insensitive manner.
17
18 if <[locale]> is LC_GLOBAL_LOCALE or not a valid locale object, the
19 behaviour is undefined.
20
21 RETURNS
22
23 If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
24 both are converted to lowercase), <<strcasecmp_l>> returns a
25 number greater than zero. If the two strings match,
26 <<strcasecmp_l>> returns zero. If <<*<[a]>>> sorts
27 lexicographically before <<*<[b]>>>, <<strcasecmp_l>> returns a
28 number less than zero.
29
30 PORTABILITY
31 <<strcasecmp_l>> is POSIX-1.2008.
32
33 <<strcasecmp_l>> requires no supporting OS subroutines. It uses
34 tolower_l() from elsewhere in this library.
35
36 QUICKREF
37 strcasecmp_l
38 */
39
40 #define _DEFAULT_SOURCE
41 #include <strings.h>
42 #include <ctype.h>
43
44 int
strcasecmp_l(const char * s1,const char * s2,struct __locale_t * locale)45 strcasecmp_l (const char *s1, const char *s2, struct __locale_t *locale)
46 {
47 int d = 0;
48 for ( ; ; )
49 {
50 const int c1 = tolower_l (*s1++, locale);
51 const int c2 = tolower_l (*s2++, locale);
52 if (((d = c1 - c2) != 0) || (c2 == '\0'))
53 break;
54 }
55 return d;
56 }
57
