misc-utils/namei.c

   1 /*-------------------------------------------------------------
   2
   3 The namei program
   4
   5 By: Roger S. Southwick
   6
   7 May 2, 1990
   8
   9
  10 Modifications by Steve Tell  March 28, 1991
  11
  12 usage: namei pathname [pathname ... ]
  13
  14 This program reads it's arguments as pathnames to any type
  15 of Unix file (symlinks, files, directories, and so forth).
  16 The program then follows each pathname until a terminal
  17 point is found (a file, directory, char device, etc).
  18 If it finds a symbolic link, we show the link, and start
  19 following it, indenting the output to show the context.
  20
  21 This program is useful for finding a "too many levels of
  22 symbolic links" problems.
  23
  24 For each line output, the program puts a file type first:
  25
  26    f: = the pathname we are currently trying to resolve
  27     d = directory
  28     D = directory that is a mount point
  29     l = symbolic link (both the link and it's contents are output)
  30     s = socket
  31     b = block device
  32     c = character device
  33     - = regular file
  34     ? = an error of some kind
  35
  36 The program prints an informative messages when we exceed
  37 the maximum number of symbolic links this system can have.
  38
  39 The program exits with a 1 status ONLY if it finds it cannot
  40 chdir to /,  or if it encounters an unknown file type.
  41
  42 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
  43 - added Native Language Support
  44
  45 -------------------------------------------------------------*/
  46
  47 #include <stdio.h>
  48 #include <unistd.h>
  49 #include <string.h>
  50 #include <stdlib.h>
  51 #include <errno.h>
  52 #include <sys/types.h>
  53 #include <sys/stat.h>
  54 #include <sys/param.h>
  55 #include "nls.h"
  56
  57 #define ERR     strerror(errno),errno
  58
  59 int symcount;
  60 int mflag = 0;
  61 int xflag = 0;
  62
  63 #ifndef MAXSYMLINKS
  64 #define MAXSYMLINKS 256
  65 #endif
  66
  67 static char *pperm(unsigned short);
  68 static void namei(char *, int);
  69 static void usage(void);
  70
  71 int
  72 main(int argc, char **argv) {
  73     extern int optind;
  74     int c;
  75     char curdir[MAXPATHLEN];
  76
  77     setlocale(LC_ALL, "");
  78     bindtextdomain(PACKAGE, LOCALEDIR);
  79     textdomain(PACKAGE);
  80
  81     if(argc < 2)
  82         usage();
  83
  84     while((c = getopt(argc, argv, "mx")) != EOF){
  85         switch(c){
  86             case 'm':
  87                 mflag = !mflag;
  88                 break;
  89
  90             case 'x':
  91                 xflag = !xflag;
  92                 break;
  93
  94             case '?':
  95             default:
  96                 usage();
  97         }
  98     }
  99
 100     if(getcwd(curdir, sizeof(curdir)) == NULL){
 101         (void)fprintf(stderr,
 102                       _("namei: unable to get current directory - %s\n"),
 103                       curdir);
 104         exit(1);
 105     }
 106
 107
 108     for(; optind < argc; optind++){
 109         (void)printf("f: %s\n", argv[optind]);
 110         symcount = 1;
 111         namei(argv[optind], 0);
 112
 113         if(chdir(curdir) == -1){
 114             (void)fprintf(stderr,
 115                           _("namei: unable to chdir to %s - %s (%d)\n"),
 116                           curdir, ERR);
 117             exit(1);
 118         }
 119     }
 120     return 0;
 121 }
 122
 123 static void
 124 usage(void) {
 125     (void)fprintf(stderr,_("usage: namei [-mx] pathname [pathname ...]\n"));
 126     exit(1);
 127 }
 128
 129 #ifndef NODEV
 130 #define NODEV           (dev_t)(-1)
 131 #endif
 132
 133 static void
 134 namei(char *file, int lev) {
 135     char *cp;
 136     char buf[BUFSIZ], sym[BUFSIZ];
 137     struct stat stb;
 138     int i;
 139     dev_t lastdev = NODEV;
 140
 141     /*
 142      * See if the file has a leading /, and if so cd to root
 143      */
 144
 145     if(*file == '/'){
 146         while(*file == '/')
 147             file++;
 148
 149         if(chdir("/") == -1){
 150             (void)fprintf(stderr,_("namei: could not chdir to root!\n"));
 151             exit(1);
 152         }
 153         for(i = 0; i < lev; i++)
 154             (void)printf("  ");
 155
 156         if(stat("/", &stb) == -1){
 157             (void)fprintf(stderr, _("namei: could not stat root!\n"));
 158             exit(1);
 159         }
 160         lastdev = stb.st_dev;
 161
 162         if(mflag)
 163             (void)printf(" d%s /\n", pperm(stb.st_mode));
 164         else
 165             (void)printf(" d /\n");
 166     }
 167
 168     for(;;){
 169
 170         if (strlen(file) >= BUFSIZ) {
 171                 fprintf(stderr,_("namei: buf overflow\n"));
 172                 return;
 173         }
 174
 175         /*
 176          * Copy up to the next / (or nil) into buf
 177          */
 178
 179         for(cp = buf; *file != '\0' && *file != '/'; cp++, file++)
 180             *cp = *file;
 181
 182         while(*file == '/')     /* eat extra /'s        */
 183             file++;
 184
 185         *cp = '\0';
 186
 187         if(buf[0] == '\0'){
 188
 189             /*
 190              * Buf is empty, so therefore we are done
 191              * with this level of file
 192              */
 193
 194             return;
 195         }
 196
 197         for(i = 0; i < lev; i++)
 198             (void)printf("  ");
 199
 200         /*
 201          * See what type of critter this file is
 202          */
 203
 204         if(lstat(buf, &stb) == -1){
 205             (void)printf(" ? %s - %s (%d)\n", buf, ERR);
 206             return;
 207         }
 208
 209         switch(stb.st_mode & S_IFMT){
 210             case S_IFDIR:
 211
 212                 /*
 213                  * File is a directory, chdir to it
 214                  */
 215
 216                 if(chdir(buf) == -1){
 217                     (void)printf(_(" ? could not chdir into %s - %s (%d)\n"), buf, ERR );
 218                     return;
 219                 }
 220                 if(xflag && lastdev != stb.st_dev && lastdev != NODEV){
 221                     /* Across mnt point */
 222                     if(mflag)
 223                         (void)printf(" D%s %s\n", pperm(stb.st_mode), buf);
 224                     else
 225                         (void)printf(" D %s\n", buf);
 226                 }
 227                 else {
 228                     if(mflag)
 229                         (void)printf(" d%s %s\n", pperm(stb.st_mode), buf);
 230                     else
 231                         (void)printf(" d %s\n", buf);
 232                 }
 233                 lastdev = stb.st_dev;
 234
 235                 (void)fflush(stdout);
 236                 break;
 237
 238             case S_IFLNK:
 239                 /*
 240                  * Sigh, another symlink.  Read its contents and
 241                  * call namei()
 242                  */
 243
 244                 bzero(sym, BUFSIZ);
 245                 if(readlink(buf, sym, BUFSIZ) == -1){
 246                     (void)printf(_(" ? problems reading symlink %s - %s (%d)\n"), buf, ERR);
 247                     return;
 248                 }
 249
 250                 if(mflag)
 251                     (void)printf(" l%s %s -> %s", pperm(stb.st_mode), buf, sym);
 252                 else
 253                     (void)printf(" l %s -> %s", buf, sym);
 254
 255                 if(symcount > 0 && symcount++ > MAXSYMLINKS){
 256                     (void)printf(_("  *** EXCEEDED UNIX LIMIT OF SYMLINKS ***\n"));
 257                     symcount = -1;
 258                 } else {
 259                     (void)printf("\n");
 260                     namei(sym, lev + 1);
 261                 }
 262                 break;
 263
 264             case S_IFCHR:
 265                 if(mflag)
 266                     (void)printf(" c%s %s\n", pperm(stb.st_mode), buf);
 267                 else
 268                     (void)printf(" c %s\n", buf);
 269                 break;
 270
 271             case S_IFBLK:
 272                 if(mflag)
 273                     (void)printf(" b%s %s\n", pperm(stb.st_mode), buf);
 274                 else
 275                     (void)printf(" b %s\n", buf);
 276                 break;
 277
 278             case S_IFSOCK:
 279                 if(mflag)
 280                     (void)printf(" s%s %s\n", pperm(stb.st_mode), buf);
 281                 else
 282                     (void)printf(" s %s\n", buf);
 283                 break;
 284
 285             case S_IFREG:
 286                 if(mflag)
 287                     (void)printf(" -%s %s\n", pperm(stb.st_mode), buf);
 288                 else
 289                     (void)printf(" - %s\n", buf);
 290                 break;
 291
 292             default:
 293                 (void)fprintf(stderr,_("namei: unknown file type 0%06o on file %s\n"), stb.st_mode, buf );
 294                 exit(1);
 295
 296         }
 297     }
 298 }
 299
 300 /* Take a
 301  * Mode word, as from a struct stat, and return
 302  * a pointer to a static string containing a printable version like ls.
 303  * For example 0755 produces "rwxr-xr-x"
 304  */
 305 static char *
 306 pperm(unsigned short mode) {
 307         unsigned short m;
 308         static char buf[16];
 309         char *bp;
 310         char *lschars = "xwrxwrxwr";  /* the complete string backwards */
 311         char *cp;
 312         int i;
 313
 314         for(i = 0, cp = lschars, m = mode, bp = &buf[8];
 315             i < 9;
 316             i++, cp++, m >>= 1, bp--) {
 317
 318                 if(m & 1)
 319                         *bp = *cp;
 320                 else
 321                         *bp = '-';
 322             }
 323         buf[9] = '\0';
 324
 325         if(mode & S_ISUID)  {
 326                 if(buf[2] == 'x')
 327                         buf[2] = 's';
 328                 else
 329                         buf[2] = 'S';
 330         }
 331         if(mode & S_ISGID)  {
 332                 if(buf[5] == 'x')
 333                         buf[5] = 's';
 334                 else
 335                         buf[5] = 'S';
 336         }
 337         if(mode & S_ISVTX)  {
 338                 if(buf[8] == 'x')
 339                         buf[8] = 't';
 340                 else
 341                         buf[8] = 'T';
 342         }
 343
 344         return &buf[0];
 345 }
 346
 347