source: azure_iot_hub/trunk/musl-1.1.18/src/locale/locale_map.c@ 388

#include <locale.h>
#include <string.h>
#include "locale_impl.h"
#include "libc.h"
#include "atomic.h"

const char *__lctrans_impl(const char *msg, const struct __locale_map *lm)
{
        const char *trans = 0;
        if (lm) trans = __mo_lookup(lm->map, lm->map_size, msg);
        return trans ? trans : msg;
}

const unsigned char *__map_file(const char *, size_t *);
int __munmap(void *, size_t);
char *__strchrnul(const char *, int);

static const char envvars[][12] = {
        "LC_CTYPE",
        "LC_NUMERIC",
        "LC_TIME",
        "LC_COLLATE",
        "LC_MONETARY",
        "LC_MESSAGES",
};

const struct __locale_map *__get_locale(int cat, const char *val)
{
        static volatile int lock[2];
        static void *volatile loc_head;
        const struct __locale_map *p;
        struct __locale_map *new = 0;
        const char *path = 0, *z;
        char buf[256];
        size_t l, n;

        if (!*val) {
                ((val = getenv("LC_ALL")) && *val) ||
                ((val = getenv(envvars[cat])) && *val) ||
                ((val = getenv("LANG")) && *val) ||
                (val = "C.UTF-8");
        }

        /* Limit name length and forbid leading dot or any slashes. */
        for (n=0; n<LOCALE_NAME_MAX && val[n] && val[n]!='/'; n++);
        if (val[0]=='.' || val[n]) val = "C.UTF-8";
        int builtin = (val[0]=='C' && !val[1])
                || !strcmp(val, "C.UTF-8")
                || !strcmp(val, "POSIX");

        if (builtin) {
                if (cat == LC_CTYPE && val[1]=='.')
                        return (void *)&__c_dot_utf8;
                return 0;
        }

        for (p=loc_head; p; p=p->next)
                if (!strcmp(val, p->name)) return p;

        LOCK(lock);

        for (p=loc_head; p; p=p->next)
                if (!strcmp(val, p->name)) {
                        UNLOCK(lock);
                        return p;
                }

        if (!libc.secure) path = getenv("MUSL_LOCPATH");
        /* FIXME: add a default path? */

        if (path) for (; *path; path=z+!!*z) {
                z = __strchrnul(path, ':');
                l = z - path - !!*z;
                if (l >= sizeof buf - n - 2) continue;
                memcpy(buf, path, l);
                buf[l] = '/';
                memcpy(buf+l+1, val, n);
                buf[l+1+n] = 0;
                size_t map_size;
                const void *map = __map_file(buf, &map_size);
                if (map) {
                        new = malloc(sizeof *new);
                        if (!new) {
                                __munmap((void *)map, map_size);
                                break;
                        }
                        new->map = map;
                        new->map_size = map_size;
                        memcpy(new->name, val, n);
                        new->name[n] = 0;
                        new->next = loc_head;
                        loc_head = new;
                        break;
                }
        }

        /* If no locale definition was found, make a locale map
         * object anyway to store the name, which is kept for the
         * sake of being able to do message translations at the
         * application level. */
        if (!new && (new = malloc(sizeof *new))) {
                new->map = __c_dot_utf8.map;
                new->map_size = __c_dot_utf8.map_size;
                memcpy(new->name, val, n);
                new->name[n] = 0;
                new->next = loc_head;
                loc_head = new;
        }

        /* For LC_CTYPE, never return a null pointer unless the
         * requested name was "C" or "POSIX". */
        if (!new && cat == LC_CTYPE) new = (void *)&__c_dot_utf8;

        UNLOCK(lock);
        return new;
}