commands/chown/chown.c

   1 /* chown/chgrp - Change file ownership                  Author: V. Archer */
   2
   3 /* Copyright 1991 by Vincent Archer
   4  *      You may freely redistribute this software, in source or binary
   5  *      form, provided that you do not alter this copyright mention in any
   6  *      way.
   7  */
   8
   9 /* Changed  3 Feb 93 by Kees J. Bot:  setuid execution nonsense removed.
  10  */
  11
  12 #include <sys/types.h>
  13 #include <sys/stat.h>
  14 #include <ctype.h>
  15 #include <dirent.h>
  16 #include <pwd.h>
  17 #include <grp.h>
  18 #include <string.h>
  19 #include <limits.h>
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <minix/minlib.h>
  24 #include <stdio.h>
  25
  26 #ifndef S_ISLNK
  27 #define S_ISLNK(mode)   0
  28 #define lstat           stat
  29 #endif
  30
  31 #define S_IUGID (S_ISUID|S_ISGID)
  32
  33 /* Global variables, such as flags and path names */
  34 int gflag, oflag, rflag, error, hflag = 0;
  35 char *pgmname, path[PATH_MAX + 1];
  36 uid_t nuid;
  37 gid_t ngid;
  38
  39 int main(int argc, char **argv);
  40 void do_chown(char *file);
  41 void usage(void);
  42
  43 /* Main module. If chown(1) is invoked as chgrp(1), the behaviour is nearly
  44  * identical, except that the default when a single name is given as an
  45  * argument is to take a group id rather than an user id. This allow the
  46  * non-Posix "chgrp user:group file".
  47  */
  48 int main(argc, argv)
  49 int argc;
  50 char *argv[];
  51 {
  52   char *id, *id2;
  53   struct group *grp;
  54   struct passwd *pwp;
  55   int ch;
  56
  57   if (pgmname = strrchr(*argv, '/'))
  58         pgmname++;
  59   else
  60         pgmname = *argv;
  61   gflag = strcmp(pgmname, "chgrp");
  62
  63   while((ch = getopt(argc, argv, "Rh")) != -1) {
  64         switch(ch) {
  65                 case 'R':
  66                         rflag = 1;
  67                         break;
  68                 case 'h':
  69                         hflag = 1;
  70                         break;
  71                 default:
  72                         usage();
  73         }
  74   }
  75
  76   argc -= optind;
  77   argv += optind;
  78
  79   if (argc < 2) usage();
  80
  81   id = *argv++;
  82   argc--;
  83   if (id2 = strchr(id, ':')) *id2++ = '\0';
  84   if (!id2 && !gflag) {
  85         id2 = id;
  86         id = 0;
  87   }
  88   if (id) {
  89         if (isdigit(*id))
  90                 nuid = atoi(id);
  91         else {
  92                 if (!(pwp = getpwnam(id))) {
  93                         std_err(id);
  94                         std_err(": unknown user name\n");
  95                         exit(1);
  96                 }
  97                 nuid = pwp->pw_uid;
  98         }
  99         oflag = 1;
 100   } else
 101         oflag = 0;
 102
 103   if (id2) {
 104         if (isdigit(*id2))
 105                 ngid = atoi(id2);
 106         else {
 107                 if (!(grp = getgrnam(id2))) {
 108                         std_err(id2);
 109                         std_err(": unknown group name\n");
 110                         exit(1);
 111                 }
 112                 ngid = grp->gr_gid;
 113         }
 114         gflag = 1;
 115   } else
 116         gflag = 0;
 117
 118   error = 0;
 119   while (argc--) do_chown(*argv++);
 120   return(error);
 121 }
 122
 123 /* Apply the user/group modification here.
 124  */
 125 void do_chown(file)
 126 char *file;
 127 {
 128   DIR *dirp;
 129   struct dirent *entp;
 130   char *namp;
 131   struct stat st;
 132
 133   if (lstat(file, &st)) {
 134         perror(file);
 135         error = 1;
 136         return;
 137   }
 138
 139   if (S_ISLNK(st.st_mode) && rflag) return;     /* Note: violates POSIX. */
 140
 141   if (S_ISLNK(st.st_mode) && hflag) {
 142         fprintf(stderr, "chown: cannot lchown %s\n", file);
 143         error = 1;
 144   }
 145
 146   if (chown(file, oflag ? nuid : st.st_uid, gflag ? ngid : st.st_gid)) {
 147         perror(file);
 148         error = 1;
 149   }
 150
 151   if (S_ISDIR(st.st_mode) && rflag) {
 152         if (!(dirp = opendir(file))) {
 153                 perror(file);
 154                 error = 1;
 155                 return;
 156         }
 157         if (path != file) strcpy(path, file);
 158         namp = path + strlen(path);
 159         *namp++ = '/';
 160         while (entp = readdir(dirp))
 161                 if (entp->d_name[0] != '.' ||
 162                     (entp->d_name[1] &&
 163                      (entp->d_name[1] != '.' || entp->d_name[2]))) {
 164                         strcpy(namp, entp->d_name);
 165                         do_chown(path);
 166                 }
 167         closedir(dirp);
 168         *--namp = '\0';
 169   }
 170 }
 171
 172 /* Posix prototype of the chown/chgrp function */
 173 void usage()
 174 {
 175   std_err("Usage: ");
 176   std_err(pgmname);
 177   std_err(gflag ? " owner[:group]" : " [owner:]group");
 178   std_err(" file...\n");
 179   exit(1);
 180 }