lib/utilunix.c

   1 /* Various utilities - Unix variants
   2    Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
   3    2004, 2005, 2007 Free Software Foundation, Inc.
   4    Written 1994, 1995, 1996 by:
   5    Miguel de Icaza, Janne Kukonlehto, Dugan Porter,
   6    Jakub Jelinek, Mauricio Plaza.
   7
   8    The mc_realpath routine is mostly from uClibc package, written
   9    by Rick Sladkey <jrs@world.std.com>
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  24
  25 /** \file utilunix.c
  26  *  \brief Source: various utilities - Unix variant
  27  */
  28
  29 #include <config.h>
  30
  31 #include <ctype.h>
  32 #include <errno.h>
  33 #include <limits.h>
  34 #include <signal.h>
  35 #include <stdarg.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <fcntl.h>
  40 #include <sys/param.h>
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <sys/wait.h>
  44 #ifdef HAVE_SYS_IOCTL_H
  45 #   include <sys/ioctl.h>
  46 #endif
  47 #include <unistd.h>
  48 #include <pwd.h>
  49 #include <grp.h>
  50
  51 #include "lib/global.h"
  52 #include "src/execute.h"
  53 #include "src/wtools.h"         /* message() */
  54
  55 struct sigaction startup_handler;
  56
  57 #define UID_CACHE_SIZE 200
  58 #define GID_CACHE_SIZE 30
  59
  60 typedef struct {
  61     int  index;
  62     char *string;
  63 } int_cache;
  64
  65 static int_cache uid_cache [UID_CACHE_SIZE];
  66 static int_cache gid_cache [GID_CACHE_SIZE];
  67
  68 static char *i_cache_match (int id, int_cache *cache, int size)
  69 {
  70     int i;
  71
  72     for (i = 0; i < size; i++)
  73         if (cache [i].index == id)
  74             return cache [i].string;
  75     return 0;
  76 }
  77
  78 static void i_cache_add (int id, int_cache *cache, int size, char *text,
  79                          int *last)
  80 {
  81     g_free (cache [*last].string);
  82     cache [*last].string = g_strdup (text);
  83     cache [*last].index = id;
  84     *last = ((*last)+1) % size;
  85 }
  86
  87 char *get_owner (int uid)
  88 {
  89     struct passwd *pwd;
  90     static char ibuf [10];
  91     char   *name;
  92     static int uid_last;
  93
  94     if ((name = i_cache_match (uid, uid_cache, UID_CACHE_SIZE)) != NULL)
  95         return name;
  96
  97     pwd = getpwuid (uid);
  98     if (pwd){
  99         i_cache_add (uid, uid_cache, UID_CACHE_SIZE, pwd->pw_name, &uid_last);
 100         return pwd->pw_name;
 101     }
 102     else {
 103         g_snprintf (ibuf, sizeof (ibuf), "%d", uid);
 104         return ibuf;
 105     }
 106 }
 107
 108 char *get_group (int gid)
 109 {
 110     struct group *grp;
 111     static char gbuf [10];
 112     char *name;
 113     static int  gid_last;
 114
 115     if ((name = i_cache_match (gid, gid_cache, GID_CACHE_SIZE)) != NULL)
 116         return name;
 117
 118     grp = getgrgid (gid);
 119     if (grp){
 120         i_cache_add (gid, gid_cache, GID_CACHE_SIZE, grp->gr_name, &gid_last);
 121         return grp->gr_name;
 122     } else {
 123         g_snprintf (gbuf, sizeof (gbuf), "%d", gid);
 124         return gbuf;
 125     }
 126 }
 127
 128 /* Since ncurses uses a handler that automatically refreshes the */
 129 /* screen after a SIGCONT, and we don't want this behavior when */
 130 /* spawning a child, we save the original handler here */
 131 void save_stop_handler (void)
 132 {
 133     sigaction (SIGTSTP, NULL, &startup_handler);
 134 }
 135
 136 int my_system (int flags, const char *shell, const char *command)
 137 {
 138     struct sigaction ignore, save_intr, save_quit, save_stop;
 139     pid_t pid;
 140     int status = 0;
 141
 142     ignore.sa_handler = SIG_IGN;
 143     sigemptyset (&ignore.sa_mask);
 144     ignore.sa_flags = 0;
 145
 146     sigaction (SIGINT, &ignore, &save_intr);
 147     sigaction (SIGQUIT, &ignore, &save_quit);
 148
 149     /* Restore the original SIGTSTP handler, we don't want ncurses' */
 150     /* handler messing the screen after the SIGCONT */
 151     sigaction (SIGTSTP, &startup_handler, &save_stop);
 152
 153     if ((pid = fork ()) < 0){
 154         fprintf (stderr, "\n\nfork () = -1\n");
 155         return -1;
 156     }
 157     if (pid == 0){
 158         signal (SIGINT, SIG_DFL);
 159         signal (SIGQUIT, SIG_DFL);
 160         signal (SIGTSTP, SIG_DFL);
 161         signal (SIGCHLD, SIG_DFL);
 162
 163         if (flags & EXECUTE_AS_SHELL)
 164             execl (shell, shell, "-c", command, (char *) NULL);
 165         else
 166         {
 167             gchar **shell_tokens;
 168             const gchar *only_cmd;
 169             shell_tokens = g_strsplit(shell," ", 2);
 170
 171             if (shell_tokens == NULL)
 172                 only_cmd = shell;
 173             else
 174                 only_cmd = (*shell_tokens) ? *shell_tokens: shell;
 175
 176             execlp (only_cmd, shell, command, (char *) NULL);
 177
 178             /*
 179               execlp will replace current process,
 180               therefore no sence in call of g_strfreev().
 181               But this keeped for estetic reason :)
 182             */
 183             g_strfreev(shell_tokens);
 184
 185         }
 186
 187         _exit (127);            /* Exec error */
 188     } else {
 189         while (waitpid (pid, &status, 0) < 0)
 190             if (errno != EINTR){
 191                 status = -1;
 192                 break;
 193             }
 194     }
 195     sigaction (SIGINT,  &save_intr, NULL);
 196     sigaction (SIGQUIT, &save_quit, NULL);
 197     sigaction (SIGTSTP, &save_stop, NULL);
 198
 199     return WEXITSTATUS(status);
 200 }
 201
 202
 203 /*
 204  * Perform tilde expansion if possible.
 205  * Always return a newly allocated string, even if it's unchanged.
 206  */
 207 char *
 208 tilde_expand (const char *directory)
 209 {
 210     struct passwd *passwd;
 211     const char *p, *q;
 212     char *name;
 213
 214     if (*directory != '~')
 215         return g_strdup (directory);
 216
 217     p = directory + 1;
 218
 219     /* d = "~" or d = "~/" */
 220     if (!(*p) || (*p == PATH_SEP)) {
 221         passwd = getpwuid (geteuid ());
 222         q = (*p == PATH_SEP) ? p + 1 : "";
 223     } else {
 224         q = strchr (p, PATH_SEP);
 225         if (!q) {
 226             passwd = getpwnam (p);
 227         } else {
 228             name = g_strndup (p, q - p);
 229             passwd = getpwnam (name);
 230             q++;
 231             g_free (name);
 232         }
 233     }
 234
 235     /* If we can't figure the user name, leave tilde unexpanded */
 236     if (!passwd)
 237         return g_strdup (directory);
 238
 239     return g_strconcat (passwd->pw_dir, PATH_SEP_STR, q, (char *) NULL);
 240 }
 241
 242 /*
 243  * Return the directory where mc should keep its temporary files.
 244  * This directory is (in Bourne shell terms) "${TMPDIR=/tmp}/mc-$USER"
 245  * When called the first time, the directory is created if needed.
 246  * The first call should be done early, since we are using fprintf()
 247  * and not message() to report possible problems.
 248  */
 249 const char *
 250 mc_tmpdir (void)
 251 {
 252     static char buffer[64];
 253     static const char *tmpdir;
 254     const char *sys_tmp;
 255     struct passwd *pwd;
 256     struct stat st;
 257     const char *error = NULL;
 258
 259     /* Check if already correctly initialized */
 260     if (tmpdir && lstat (tmpdir, &st) == 0 && S_ISDIR (st.st_mode) &&
 261         st.st_uid == getuid () && (st.st_mode & 0777) == 0700)
 262         return tmpdir;
 263
 264     sys_tmp = getenv ("TMPDIR");
 265     if (!sys_tmp || sys_tmp[0] != '/') {
 266         sys_tmp = TMPDIR_DEFAULT;
 267     }
 268
 269     pwd = getpwuid (getuid ());
 270
 271     if (pwd)
 272         g_snprintf (buffer, sizeof (buffer), "%s/mc-%s", sys_tmp,
 273                 pwd->pw_name);
 274     else
 275         g_snprintf (buffer, sizeof (buffer), "%s/mc-%lu", sys_tmp,
 276                 (unsigned long) getuid ());
 277
 278     canonicalize_pathname (buffer);
 279
 280     if (lstat (buffer, &st) == 0) {
 281         /* Sanity check for existing directory */
 282         if (!S_ISDIR (st.st_mode))
 283             error = _("%s is not a directory\n");
 284         else if (st.st_uid != getuid ())
 285             error = _("Directory %s is not owned by you\n");
 286         else if (((st.st_mode & 0777) != 0700)
 287                  && (chmod (buffer, 0700) != 0))
 288             error = _("Cannot set correct permissions for directory %s\n");
 289     } else {
 290         /* Need to create directory */
 291         if (mkdir (buffer, S_IRWXU) != 0) {
 292             fprintf (stderr,
 293                      _("Cannot create temporary directory %s: %s\n"),
 294                      buffer, unix_error_string (errno));
 295             error = "";
 296         }
 297     }
 298
 299     if (error != NULL) {
 300         int test_fd;
 301         char *test_fn, *fallback_prefix;
 302         int fallback_ok = 0;
 303
 304         if (*error)
 305             fprintf (stderr, error, buffer);
 306
 307         /* Test if sys_tmp is suitable for temporary files */
 308         fallback_prefix = g_strdup_printf ("%s/mctest", sys_tmp);
 309         test_fd = mc_mkstemps (&test_fn, fallback_prefix, NULL);
 310         g_free (fallback_prefix);
 311         if (test_fd != -1) {
 312             close (test_fd);
 313             test_fd = open (test_fn, O_RDONLY);
 314             if (test_fd != -1) {
 315                 close (test_fd);
 316                 unlink (test_fn);
 317                 fallback_ok = 1;
 318             }
 319         }
 320
 321         if (fallback_ok) {
 322             fprintf (stderr, _("Temporary files will be created in %s\n"),
 323                      sys_tmp);
 324             g_snprintf (buffer, sizeof (buffer), "%s", sys_tmp);
 325             error = NULL;
 326         } else {
 327             fprintf (stderr, _("Temporary files will not be created\n"));
 328             g_snprintf (buffer, sizeof (buffer), "%s", "/dev/null/");
 329         }
 330
 331         fprintf (stderr, "%s\n", _("Press any key to continue..."));
 332         getc (stdin);
 333     }
 334
 335     tmpdir = buffer;
 336
 337     if (!error)
 338         g_setenv ("MC_TMPDIR", tmpdir, TRUE);
 339
 340     return tmpdir;
 341 }
 342
 343
 344 /* Pipes are guaranteed to be able to hold at least 4096 bytes */
 345 /* More than that would be unportable */
 346 #define MAX_PIPE_SIZE 4096
 347
 348 static int error_pipe[2];       /* File descriptors of error pipe */
 349 static int old_error;           /* File descriptor of old standard error */
 350
 351 /* Creates a pipe to hold standard error for a later analysis. */
 352 /* The pipe can hold 4096 bytes. Make sure no more is written */
 353 /* or a deadlock might occur. */
 354 void open_error_pipe (void)
 355 {
 356     if (pipe (error_pipe) < 0){
 357         message (D_NORMAL, _("Warning"), _(" Pipe failed "));
 358     }
 359     old_error = dup (2);
 360     if(old_error < 0 || close(2) || dup (error_pipe[1]) != 2){
 361         message (D_NORMAL, _("Warning"), _(" Dup failed "));
 362
 363         close (error_pipe[0]);
 364         error_pipe[0] = -1;
 365     }
 366     else
 367     {
 368         /*
 369          * Settng stderr in nonblocking mode as we close it earlier, than
 370          * program stops. We try to read some error at program startup,
 371          * but we should not block on it.
 372          *
 373          * TODO: make piped stdin/stderr poll()/select()able to get rid
 374          * of following hack.
 375          */
 376         int fd_flags;
 377         fd_flags = fcntl (error_pipe[0], F_GETFL, NULL);
 378         if (fd_flags != -1)
 379         {
 380             fd_flags |= O_NONBLOCK;
 381             if (fcntl(error_pipe[0], F_SETFL, fd_flags) == -1)
 382             {
 383                 /* TODO: handle it somehow */
 384             }
 385         }
 386     }
 387     /* we never write there */
 388     close (error_pipe[1]);
 389     error_pipe[1] = -1;
 390 }
 391
 392 /*
 393  * Returns true if an error was displayed
 394  * error: -1 - ignore errors, 0 - display warning, 1 - display error
 395  * text is prepended to the error message from the pipe
 396  */
 397 int
 398 close_error_pipe (int error, const char *text)
 399 {
 400     const char *title;
 401     char msg[MAX_PIPE_SIZE];
 402     int len = 0;
 403
 404     /* already closed */
 405     if (error_pipe[0] == -1)
 406         return 0;
 407
 408     if (error)
 409         title = MSG_ERROR;
 410     else
 411         title = _("Warning");
 412     if (old_error >= 0){
 413         close (2);
 414         dup (old_error);
 415         close (old_error);
 416         len = read (error_pipe[0], msg, MAX_PIPE_SIZE - 1);
 417
 418         if (len >= 0)
 419             msg[len] = 0;
 420         close (error_pipe[0]);
 421         error_pipe[0] = -1;
 422     }
 423     if (error < 0)
 424         return 0;       /* Just ignore error message */
 425     if (text == NULL){
 426         if (len <= 0)
 427             return 0;   /* Nothing to show */
 428
 429         /* Show message from pipe */
 430         message (error, title, "%s", msg);
 431     } else {
 432         /* Show given text and possible message from pipe */
 433         message (error, title, " %s \n %s ", text, msg);
 434     }
 435     return 1;
 436 }
 437
 438 /*
 439  * Canonicalize path, and return a new path.  Do everything in place.
 440  * The new path differs from path in:
 441  *      Multiple `/'s are collapsed to a single `/'.
 442  *      Leading `./'s and trailing `/.'s are removed.
 443  *      Trailing `/'s are removed.
 444  *      Non-leading `../'s and trailing `..'s are handled by removing
 445  *      portions of the path.
 446  * Well formed UNC paths are modified only in the local part.
 447  */
 448 void
 449 custom_canonicalize_pathname (char *path, CANON_PATH_FLAGS flags)
 450 {
 451     char *p, *s;
 452     int len;
 453     char *lpath = path; /* path without leading UNC part */
 454
 455     /* Detect and preserve UNC paths: //server/... */
 456     if ( ( flags & CANON_PATH_GUARDUNC ) && path[0] == PATH_SEP && path[1] == PATH_SEP) {
 457         p = path + 2;
 458         while (p[0] && p[0] != '/')
 459             p++;
 460         if (p[0] == '/' && p > path + 2)
 461             lpath = p;
 462     }
 463
 464     if (!lpath[0] || !lpath[1])
 465         return;
 466
 467     if ( flags & CANON_PATH_JOINSLASHES ) {
 468         /* Collapse multiple slashes */
 469         p = lpath;
 470         while (*p) {
 471             if (p[0] == PATH_SEP && p[1] == PATH_SEP) {
 472                 s = p + 1;
 473                 while (*(++s) == PATH_SEP);
 474                 str_move (p + 1, s);
 475             }
 476             p++;
 477         }
 478     }
 479
 480     if ( flags & CANON_PATH_JOINSLASHES ) {
 481         /* Collapse "/./" -> "/" */
 482         p = lpath;
 483         while (*p) {
 484             if (p[0] == PATH_SEP && p[1] == '.' && p[2] == PATH_SEP)
 485                 str_move (p, p + 2);
 486             else
 487                 p++;
 488         }
 489     }
 490
 491     if ( flags & CANON_PATH_REMSLASHDOTS ) {
 492         /* Remove trailing slashes */
 493         p = lpath + strlen (lpath) - 1;
 494         while (p > lpath && *p == PATH_SEP)
 495             *p-- = 0;
 496
 497         /* Remove leading "./" */
 498         if (lpath[0] == '.' && lpath[1] == PATH_SEP) {
 499             if (lpath[2] == 0) {
 500                 lpath[1] = 0;
 501                 return;
 502             } else {
 503                 str_move (lpath, lpath + 2);
 504             }
 505         }
 506
 507         /* Remove trailing "/" or "/." */
 508         len = strlen (lpath);
 509         if (len < 2)
 510             return;
 511         if (lpath[len - 1] == PATH_SEP) {
 512             lpath[len - 1] = 0;
 513         } else {
 514             if (lpath[len - 1] == '.' && lpath[len - 2] == PATH_SEP) {
 515                 if (len == 2) {
 516                     lpath[1] = 0;
 517                     return;
 518                 } else {
 519                     lpath[len - 2] = 0;
 520                 }
 521             }
 522         }
 523     }
 524
 525     if ( flags & CANON_PATH_REMDOUBLEDOTS ) {
 526         /* Collapse "/.." with the previous part of path */
 527         p = lpath;
 528         while (p[0] && p[1] && p[2]) {
 529             if ((p[0] != PATH_SEP || p[1] != '.' || p[2] != '.')
 530                 || (p[3] != PATH_SEP && p[3] != 0)) {
 531                 p++;
 532                 continue;
 533             }
 534
 535             /* search for the previous token */
 536             s = p - 1;
 537             while (s >= lpath && *s != PATH_SEP)
 538                 s--;
 539
 540             s++;
 541
 542             /* If the previous token is "..", we cannot collapse it */
 543             if (s[0] == '.' && s[1] == '.' && s + 2 == p) {
 544                 p += 3;
 545                 continue;
 546             }
 547
 548             if (p[3] != 0) {
 549                 if (s == lpath && *s == PATH_SEP) {
 550                     /* "/../foo" -> "/foo" */
 551                     str_move (s + 1, p + 4);
 552                 } else {
 553                     /* "token/../foo" -> "foo" */
 554                     str_move (s, p + 4);
 555                 }
 556                 p = (s > lpath) ? s - 1 : s;
 557                 continue;
 558             }
 559
 560             /* trailing ".." */
 561             if (s == lpath) {
 562                 /* "token/.." -> "." */
 563                 if (lpath[0] != PATH_SEP) {
 564                     lpath[0] = '.';
 565                 }
 566                 lpath[1] = 0;
 567             } else {
 568                 /* "foo/token/.." -> "foo" */
 569                 if (s == lpath + 1)
 570                     s[0] = 0;
 571                 else
 572                     s[-1] = 0;
 573                 break;
 574             }
 575
 576             break;
 577         }
 578     }
 579 }
 580
 581 void
 582 canonicalize_pathname (char *path)
 583 {
 584     custom_canonicalize_pathname (path, CANON_PATH_ALL);
 585 }
 586
 587 #ifdef HAVE_GET_PROCESS_STATS
 588 #    include <sys/procstats.h>
 589
 590 int gettimeofday (struct timeval *tp, void *tzp)
 591 {
 592   return get_process_stats(tp, PS_SELF, 0, 0);
 593 }
 594 #endif /* HAVE_GET_PROCESS_STATS */
 595
 596 char *
 597 mc_realpath (const char *path, char resolved_path[])
 598 {
 599 #ifdef  USE_SYSTEM_REALPATH
 600     return realpath (path, resolved_path);
 601 #else
 602     char copy_path[PATH_MAX];
 603     char link_path[PATH_MAX];
 604     char got_path[PATH_MAX];
 605     char *new_path = got_path;
 606     char *max_path;
 607     int readlinks = 0;
 608     int n;
 609
 610     /* Make a copy of the source path since we may need to modify it. */
 611     if (strlen (path) >= PATH_MAX - 2) {
 612         errno = ENAMETOOLONG;
 613         return NULL;
 614     }
 615     strcpy (copy_path, path);
 616     path = copy_path;
 617     max_path = copy_path + PATH_MAX - 2;
 618     /* If it's a relative pathname use getwd for starters. */
 619     if (*path != '/') {
 620         /* Ohoo... */
 621 #ifdef HAVE_GETCWD
 622         getcwd (new_path, PATH_MAX - 1);
 623 #else
 624         getwd (new_path);
 625 #endif
 626         new_path += strlen (new_path);
 627         if (new_path[-1] != '/')
 628             *new_path++ = '/';
 629     } else {
 630         *new_path++ = '/';
 631         path++;
 632     }
 633     /* Expand each slash-separated pathname component. */
 634     while (*path != '\0') {
 635         /* Ignore stray "/". */
 636         if (*path == '/') {
 637             path++;
 638             continue;
 639         }
 640         if (*path == '.') {
 641             /* Ignore ".". */
 642             if (path[1] == '\0' || path[1] == '/') {
 643                 path++;
 644                 continue;
 645             }
 646             if (path[1] == '.') {
 647                 if (path[2] == '\0' || path[2] == '/') {
 648                     path += 2;
 649                     /* Ignore ".." at root. */
 650                     if (new_path == got_path + 1)
 651                         continue;
 652                     /* Handle ".." by backing up. */
 653                     while ((--new_path)[-1] != '/');
 654                     continue;
 655                 }
 656             }
 657         }
 658         /* Safely copy the next pathname component. */
 659         while (*path != '\0' && *path != '/') {
 660             if (path > max_path) {
 661                 errno = ENAMETOOLONG;
 662                 return NULL;
 663             }
 664             *new_path++ = *path++;
 665         }
 666 #ifdef S_IFLNK
 667         /* Protect against infinite loops. */
 668         if (readlinks++ > MAXSYMLINKS) {
 669             errno = ELOOP;
 670             return NULL;
 671         }
 672         /* See if latest pathname component is a symlink. */
 673         *new_path = '\0';
 674         n = readlink (got_path, link_path, PATH_MAX - 1);
 675         if (n < 0) {
 676             /* EINVAL means the file exists but isn't a symlink. */
 677             if (errno != EINVAL) {
 678                 /* Make sure it's null terminated. */
 679                 *new_path = '\0';
 680                 strcpy (resolved_path, got_path);
 681                 return NULL;
 682             }
 683         } else {
 684             /* Note: readlink doesn't add the null byte. */
 685             link_path[n] = '\0';
 686             if (*link_path == '/')
 687                 /* Start over for an absolute symlink. */
 688                 new_path = got_path;
 689             else
 690                 /* Otherwise back up over this component. */
 691                 while (*(--new_path) != '/');
 692             /* Safe sex check. */
 693             if (strlen (path) + n >= PATH_MAX - 2) {
 694                 errno = ENAMETOOLONG;
 695                 return NULL;
 696             }
 697             /* Insert symlink contents into path. */
 698             strcat (link_path, path);
 699             strcpy (copy_path, link_path);
 700             path = copy_path;
 701         }
 702 #endif                          /* S_IFLNK */
 703         *new_path++ = '/';
 704     }
 705     /* Delete trailing slash but don't whomp a lone slash. */
 706     if (new_path != got_path + 1 && new_path[-1] == '/')
 707         new_path--;
 708     /* Make sure it's null terminated. */
 709     *new_path = '\0';
 710     strcpy (resolved_path, got_path);
 711     return resolved_path;
 712 #endif  /* USE_SYSTEM_REALPATH */
 713 }
 714
 715 /* Return the index of the permissions triplet */
 716 int
 717 get_user_permissions (struct stat *st) {
 718     static gboolean initialized = FALSE;
 719     static gid_t *groups;
 720     static int ngroups;
 721     static uid_t uid;
 722     int i;
 723
 724     if (!initialized) {
 725         uid = geteuid ();
 726
 727         ngroups = getgroups (0, NULL);
 728         if (ngroups == -1)
 729             ngroups = 0;        /* ignore errors */
 730
 731         /* allocate space for one element in addition to what
 732          * will be filled by getgroups(). */
 733         groups = g_new (gid_t, ngroups + 1);
 734
 735         if (ngroups != 0) {
 736             ngroups = getgroups (ngroups, groups);
 737             if (ngroups == -1)
 738                 ngroups = 0;    /* ignore errors */
 739         }
 740
 741         /* getgroups() may or may not return the effective group ID,
 742          * so we always include it at the end of the list. */
 743         groups[ngroups++] = getegid ();
 744
 745         initialized = TRUE;
 746     }
 747
 748     if (st->st_uid == uid || uid == 0)
 749        return 0;
 750
 751     for (i = 0; i < ngroups; i++) {
 752         if (st->st_gid == groups[i])
 753             return 1;
 754     }
 755
 756     return 2;
 757 }