commands/simple/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;
  35 char *pgmname, path[PATH_MAX + 1];
  36 uid_t nuid;
  37 gid_t ngid;
  38
  39 _PROTOTYPE(int main, (int argc, char **argv));
  40 _PROTOTYPE(void do_chown, (char *file));
  41 _PROTOTYPE(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  * The single option switch used by chown/chgrp (-R) does not warrant a
  48  * call to the getopt stuff. The two others flags (-g, -u) are set from
  49  * the program name and arguments.
  50  */
  51 int main(argc, argv)
  52 int argc;
  53 char *argv[];
  54 {
  55   char *id, *id2;
  56   struct group *grp;
  57   struct passwd *pwp;
  58
  59   if (pgmname = strrchr(*argv, '/'))
  60         pgmname++;
  61   else
  62         pgmname = *argv;
  63   argc--;
  64   argv++;
  65   gflag = strcmp(pgmname, "chgrp");
  66
  67   if (argc && **argv == '-' && argv[0][1] == 'R') {
  68         argc--;
  69         argv++;
  70         rflag = 1;
  71   }
  72   if (argc < 2) usage();
  73
  74   id = *argv++;
  75   argc--;
  76   if (id2 = strchr(id, ':')) *id2++ = '\0';
  77   if (!id2 && !gflag) {
  78         id2 = id;
  79         id = 0;
  80   }
  81   if (id) {
  82         if (isdigit(*id))
  83                 nuid = atoi(id);
  84         else {
  85                 if (!(pwp = getpwnam(id))) {
  86                         std_err(id);
  87                         std_err(": unknown user name\n");
  88                         exit(1);
  89                 }
  90                 nuid = pwp->pw_uid;
  91         }
  92         oflag = 1;
  93   } else
  94         oflag = 0;
  95
  96   if (id2) {
  97         if (isdigit(*id2))
  98                 ngid = atoi(id2);
  99         else {
 100                 if (!(grp = getgrnam(id2))) {
 101                         std_err(id2);
 102                         std_err(": unknown group name\n");
 103                         exit(1);
 104                 }
 105                 ngid = grp->gr_gid;
 106         }
 107         gflag = 1;
 108   } else
 109         gflag = 0;
 110
 111   error = 0;
 112   while (argc--) do_chown(*argv++);
 113   return(error);
 114 }
 115
 116 /* Apply the user/group modification here.
 117  */
 118 void do_chown(file)
 119 char *file;
 120 {
 121   DIR *dirp;
 122   struct dirent *entp;
 123   char *namp;
 124   struct stat st;
 125
 126   if (lstat(file, &st)) {
 127         perror(file);
 128         error = 1;
 129         return;
 130   }
 131
 132   if (S_ISLNK(st.st_mode) && rflag) return;     /* Note: violates POSIX. */
 133
 134   if (chown(file, oflag ? nuid : st.st_uid, gflag ? ngid : st.st_gid)) {
 135         perror(file);
 136         error = 1;
 137   }
 138
 139   if (S_ISDIR(st.st_mode) && rflag) {
 140         if (!(dirp = opendir(file))) {
 141                 perror(file);
 142                 error = 1;
 143                 return;
 144         }
 145         if (path != file) strcpy(path, file);
 146         namp = path + strlen(path);
 147         *namp++ = '/';
 148         while (entp = readdir(dirp))
 149                 if (entp->d_name[0] != '.' ||
 150                     (entp->d_name[1] &&
 151                      (entp->d_name[1] != '.' || entp->d_name[2]))) {
 152                         strcpy(namp, entp->d_name);
 153                         do_chown(path);
 154                 }
 155         closedir(dirp);
 156         *--namp = '\0';
 157   }
 158 }
 159
 160 /* Posix prototype of the chown/chgrp function */
 161 void usage()
 162 {
 163   std_err("Usage: ");
 164   std_err(pgmname);
 165   std_err(gflag ? " owner[:group]" : " [owner:]group");
 166   std_err(" file...\n");
 167   exit(1);
 168 }