1 /* $OpenBSD: _get_locname.c,v 1.1 2017/09/05 03:16:13 schwarze Exp $ */
2 /*
3 * Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <errno.h>
19 #include <locale.h>
20 #include <paths.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24
25 #include "rune.h"
26 #include "rune_local.h"
27
28 /*
29 * Supplement the input with locale(1) variables from the
30 * environment, validate it, and initialize UTF-8 when needed.
31 * Return NULL on error, "" if unset (for LC_ALL only),
32 * or the name of the locale that takes effect.
33 */
34 const char *
_get_locname(int category,const char * locname)35 _get_locname(int category, const char *locname)
36 {
37 static const char *const catname[_LC_LAST - 1] = {
38 "LC_COLLATE", "LC_CTYPE", "LC_MONETARY",
39 "LC_NUMERIC", "LC_TIME", "LC_MESSAGES"
40 };
41
42 FILE *fp;
43 const char *cp;
44 int save_errno;
45
46 /* For empty input, inspect the environment. */
47 if (*locname == '\0')
48 locname = getenv("LC_ALL");
49
50 if (category != LC_ALL) {
51 if (locname == NULL || *locname == '\0')
52 locname = getenv(catname[category - 1]);
53 if (locname == NULL || *locname == '\0')
54 locname = getenv("LANG");
55 }
56
57 /*
58 * If still empty, treat LC_ALL as unset, but
59 * fall back to the default locale for other categories.
60 */
61 if (locname == NULL || *locname == '\0')
62 locname = category == LC_ALL ? "" : "C";
63
64 /* Accept and ignore all language and territory prefixes. */
65 if ((cp = strrchr(locname, '.')) == NULL)
66 return locname;
67
68 /* Reject all encodings except ASCII and UTF-8. */
69 if (strcmp(cp + 1, "UTF-8") != 0)
70 return NULL;
71
72 /* Initialize the UTF-8 character encoding locale, if needed. */
73 if (_Utf8RuneLocale != NULL)
74 return locname;
75 save_errno = errno;
76 if ((fp = fopen(_PATH_LOCALE "/UTF-8/LC_CTYPE", "re")) != NULL) {
77 _Utf8RuneLocale = _Read_RuneMagi(fp);
78 fclose(fp);
79 }
80 errno = save_errno;
81 return _Utf8RuneLocale == NULL ? NULL : locname;
82 }
83