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@misiek.eu.org>
  43 - added Native Language Support
  44
  45 -------------------------------------------------------------*/
  46
  47 #include <stdio.h>
  48 #include <unistd.h>
  49 #include <string.h>
  50 #include <sys/types.h>
  51 #include <sys/stat.h>
  52 #include <sys/param.h>
  53 #include "nls.h"
  54
  55 #ifndef __GNU_LIBRARY__
  56 extern char *sys_errlist[];
  57 #endif
  58
  59 extern int errno;
  60 #define ERR     sys_errlist[errno],errno
  61
  62 int symcount;
  63 int mflag = 0;
  64 int xflag = 0;
  65
  66 #ifndef MAXSYMLINKS
  67 #define MAXSYMLINKS 256
  68 #endif
  69
  70 static char *pperm();
  71
  72 int
  73 main(argc, argv)
  74 int argc;
  75 char *argv[];
  76 {
  77     void namei(), usage();
  78     int getopt();
  79     extern int optind;
  80     register int c;
  81     char curdir[MAXPATHLEN];
  82
  83     setlocale(LC_ALL, "");
  84     bindtextdomain(PACKAGE, LOCALEDIR);
  85     textdomain(PACKAGE);
  86
  87     if(argc < 2)
  88         usage();
  89
  90     while((c = getopt(argc, argv, "mx")) != EOF){
  91         switch(c){
  92             case 'm':
  93                 mflag = !mflag;
  94                 break;
  95
  96             case 'x':
  97                 xflag = !xflag;
  98                 break;
  99
 100             case '?':
 101             default:
 102                 usage();
 103         }
 104     }
 105
 106     if(getcwd(curdir, sizeof(curdir)) == NULL){
 107         (void)fprintf(stderr, _("namei: unable to get current directory - %s\n"), curdir);
 108         exit(1);
 109     }
 110
 111
 112     for(; optind < argc; optind++){
 113         (void)printf("f: %s\n", argv[optind]);
 114         symcount = 1;
 115         namei(argv[optind], 0);
 116
 117         if(chdir(curdir) == -1){
 118             (void)fprintf(stderr, _("namei: unable to chdir to %s - %s (%d)\n"), curdir, ERR);
 119             exit(1);
 120         }
 121     }
 122     return 0;
 123 }
 124
 125 void
 126 usage()
 127 {
 128     (void)fprintf(stderr,_("usage: namei [-mx] pathname [pathname ...]\n"));
 129     exit(1);
 130 }
 131
 132 #ifndef NODEV
 133 #define NODEV           (dev_t)(-1)
 134 #endif
 135
 136 void
 137 namei(file, lev)
 138
 139 register char *file;
 140 register int lev;
 141 {
 142     register char *cp;
 143     char buf[BUFSIZ], sym[BUFSIZ];
 144     struct stat stb;
 145     register int i;
 146     dev_t lastdev = NODEV;
 147
 148     /*
 149      * See if the file has a leading /, and if so cd to root
 150      */
 151
 152     if(*file == '/'){
 153         while(*file == '/')
 154             file++;
 155
 156         if(chdir("/") == -1){
 157             (void)fprintf(stderr,_("namei: could not chdir to root!\n"));
 158             exit(1);
 159         }
 160         for(i = 0; i < lev; i++)
 161             (void)printf("  ");
 162
 163         if(stat("/", &stb) == -1){
 164             (void)fprintf(stderr, _("namei: could not stat root!\n"));
 165             exit(1);
 166         }
 167         lastdev = stb.st_dev;
 168
 169         if(mflag)
 170             (void)printf(" d%s /\n", pperm(stb.st_mode));
 171         else
 172             (void)printf(" d /\n");
 173     }
 174
 175     for(;;){
 176
 177         /*
 178          * Copy up to the next / (or nil) into buf
 179          */
 180
 181         for(cp = buf; *file != '\0' && *file != '/'; cp++, file++)
 182             *cp = *file;
 183
 184         while(*file == '/')     /* eat extra /'s        */
 185             file++;
 186
 187         *cp = '\0';
 188
 189         if(buf[0] == '\0'){
 190
 191             /*
 192              * Buf is empty, so therefore we are done
 193              * with this level of file
 194              */
 195
 196             return;
 197         }
 198
 199         for(i = 0; i < lev; i++)
 200             (void)printf("  ");
 201
 202         /*
 203          * See what type of critter this file is
 204          */
 205
 206         if(lstat(buf, &stb) == -1){
 207             (void)printf(" ? %s - %s (%d)\n", buf, ERR);
 208             return;
 209         }
 210
 211         switch(stb.st_mode & S_IFMT){
 212             case S_IFDIR:
 213
 214                 /*
 215                  * File is a directory, chdir to it
 216                  */
 217
 218                 if(chdir(buf) == -1){
 219                     (void)printf(_(" ? could not chdir into %s - %s (%d)\n"), buf, ERR );
 220                     return;
 221                 }
 222                 if(xflag && lastdev != stb.st_dev && lastdev != NODEV){
 223                     /* Across mnt point */
 224                     if(mflag)
 225                         (void)printf(" D%s %s\n", pperm(stb.st_mode), buf);
 226                     else
 227                         (void)printf(" D %s\n", buf);
 228                 }
 229                 else {
 230                     if(mflag)
 231                         (void)printf(" d%s %s\n", pperm(stb.st_mode), buf);
 232                     else
 233                         (void)printf(" d %s\n", buf);
 234                 }
 235                 lastdev = stb.st_dev;
 236
 237                 (void)fflush(stdout);
 238                 break;
 239
 240             case S_IFLNK:
 241                 /*
 242                  * Sigh, another symlink.  Read it's contents and
 243                  * call namei()
 244                  */
 245
 246                 bzero(sym, BUFSIZ);
 247                 if(readlink(buf, sym, BUFSIZ) == -1){
 248                     (void)printf(_(" ? problems reading symlink %s - %s (%d)\n"), buf, ERR);
 249                     return;
 250                 }
 251
 252                 if(mflag)
 253                     (void)printf(" l%s %s -> %s", pperm(stb.st_mode), buf, sym);
 254                 else
 255                     (void)printf(" l %s -> %s", buf, sym);
 256
 257                 if(symcount > 0 && symcount++ > MAXSYMLINKS){
 258                     (void)printf(_("  *** EXCEEDED UNIX LIMIT OF SYMLINKS ***"));
 259                     symcount = -1;
 260                 }
 261                 (void)printf("\n");
 262                 namei(sym, lev + 1);
 263                 break;
 264
 265             case S_IFCHR:
 266                 if(mflag)
 267                     (void)printf(" c%s %s\n", pperm(stb.st_mode), buf);
 268                 else
 269                     (void)printf(" c %s\n", buf);
 270                 break;
 271
 272             case S_IFBLK:
 273                 if(mflag)
 274                     (void)printf(" b%s %s\n", pperm(stb.st_mode), buf);
 275                 else
 276                     (void)printf(" b %s\n", buf);
 277                 break;
 278
 279             case S_IFSOCK:
 280                 if(mflag)
 281                     (void)printf(" s%s %s\n", pperm(stb.st_mode), buf);
 282                 else
 283                     (void)printf(" s %s\n", buf);
 284                 break;
 285
 286             case S_IFREG:
 287                 if(mflag)
 288                     (void)printf(" -%s %s\n", pperm(stb.st_mode), buf);
 289                 else
 290                     (void)printf(" - %s\n", buf);
 291                 break;
 292
 293             default:
 294                 (void)fprintf(stderr,_("namei: unknown file type 0%06o on file %s\n"), stb.st_mode, buf );
 295                 exit(1);
 296
 297         }
 298     }
 299 }
 300
 301 /* Take a
 302  * Mode word, as from a struct stat, and return
 303  * a pointer to a static string containing a printable version like ls.
 304  * For example 0755 produces "rwxr-xr-x"
 305  */
 306 static char *
 307 pperm(mode)
 308 unsigned short mode;
 309 {
 310         unsigned short m;
 311         static char buf[16];
 312         char *bp;
 313         char *lschars = "xwrxwrxwr";  /* the complete string backwards */
 314         char *cp;
 315         int i;
 316
 317         for(i = 0, cp = lschars, m = mode, bp = &buf[8];
 318             i < 9;
 319             i++, cp++, m >>= 1, bp--) {
 320
 321                 if(m & 1)
 322                         *bp = *cp;
 323                 else
 324                         *bp = '-';
 325             }
 326         buf[9] = '\0';
 327
 328         if(mode & S_ISUID)  {
 329                 if(buf[2] == 'x')
 330                         buf[2] = 's';
 331                 else
 332                         buf[2] = 'S';
 333         }
 334         if(mode & S_ISGID)  {
 335                 if(buf[5] == 'x')
 336                         buf[5] = 's';
 337                 else
 338                         buf[5] = 'S';
 339         }
 340         if(mode & S_ISVTX)  {
 341                 if(buf[8] == 'x')
 342                         buf[8] = 't';
 343                 else
 344                         buf[8] = 'T';
 345         }
 346
 347         return &buf[0];
 348 }
 349
 350