github.com/afumu/libc@v0.0.6/musl/src/locale/catopen.c (about)

     1  #define _BSD_SOURCE
     2  #include <nl_types.h>
     3  #include <string.h>
     4  #include <stdint.h>
     5  #include <endian.h>
     6  #include <errno.h>
     7  #include <langinfo.h>
     8  #include <locale.h>
     9  #include <sys/mman.h>
    10  #include "libc.h"
    11  
    12  #define V(p) be32toh(*(uint32_t *)(p))
    13  
    14  static nl_catd do_catopen(const char *name)
    15  {
    16  	size_t size;
    17  	const unsigned char *map = __map_file(name, &size);
    18  	/* Size recorded in the file must match file size; otherwise
    19  	 * the information needed to unmap the file will be lost. */
    20  	if (!map || V(map) != 0xff88ff89 || 20+V(map+8) != size) {
    21  		if(map) munmap((void *)map, size);
    22  		errno = ENOENT;
    23  		return (nl_catd)-1;
    24  	}
    25  	return (nl_catd)map;
    26  }
    27  
    28  nl_catd catopen(const char *name, int oflag)
    29  {
    30  	nl_catd catd;
    31  
    32  	if (strchr(name, '/')) return do_catopen(name);
    33  
    34  	char buf[PATH_MAX];
    35  	size_t i;
    36  	const char *path, *lang, *p, *z;
    37  	if (libc.secure || !(path = getenv("NLSPATH"))) {
    38  		errno = ENOENT;
    39  		return (nl_catd)-1;
    40  	}
    41  	lang = oflag ? nl_langinfo(_NL_LOCALE_NAME(LC_MESSAGES)) : getenv("LANG");
    42  	if (!lang) lang = "";
    43  	for (p=path; *p; p=z) {
    44  		i = 0;
    45  		z = __strchrnul(p, ':');
    46  		for (; p<z; p++) {
    47  			const char *v;
    48  			size_t l;
    49  			if (*p!='%') v=p, l=1;
    50  			else switch (*++p) {
    51  			case 'N': v=name; l=strlen(v); break;
    52  			case 'L': v=lang; l=strlen(v); break;
    53  			case 'l': v=lang; l=strcspn(v,"_.@"); break;
    54  			case 't':
    55  				v=__strchrnul(lang,'_');
    56  				if (*v) v++;
    57  				l=strcspn(v,".@");
    58  				break;
    59  			case 'c': v="UTF-8"; l=5; break;
    60  			case '%': v="%"; l=1; break;
    61  			default: v=0;
    62  			}
    63  			if (!v || l >= sizeof buf - i) {
    64  				break;
    65  			}
    66  			memcpy(buf+i, v, l);
    67  			i += l;
    68  		}
    69  		if (!*z && (p<z || !i)) break;
    70  		if (p<z) continue;
    71  		if (*z) z++;
    72  		buf[i] = 0;
    73  		/* Leading : or :: in NLSPATH is same as %N */
    74  		catd = do_catopen(i ? buf : name);
    75  		if (catd != (nl_catd)-1) return catd;
    76  	}
    77  	errno = ENOENT;
    78  	return (nl_catd)-1;
    79  }