chmod.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <sys/stat.h>
   5 #include "internal.h"
   6
   7 const char      chmod_usage[] = "chmod [-R] mode file [file ...]\n"
   8 "\nmode may be an octal integer representing the bit pattern for the\n"
   9 "\tnew mode, or a symbolic value matching the pattern\n"
  10 "\t[ugoa]{+|-|=}[rwxst] .\n"
  11 "\t\tu:\tUser\n"
  12 "\t\tg:\tGroup\n"
  13 "\t\to:\tOthers\n"
  14 "\t\ta:\tAll\n"
  15 "\n"
  16 "\n+:\tAdd privilege\n"
  17 "\n-:\tRemove privilege\n"
  18 "\n=:\tSet privilege\n"
  19 "\n"
  20 "\t\tr:\tRead\n"
  21 "\t\tw:\tWrite\n"
  22 "\t\tx:\tExecute\n"
  23 "\t\ts:\tSet User ID\n"
  24 "\t\tt:\t\"Sticky\" Text\n"
  25 "\n"
  26 "\tModes may be concatenated, as in \"u=rwx,g=rx,o=rx,-t,-s\n"
  27 "\n"
  28 "\t-R:\tRecursively change the mode of all files and directories\n"
  29 "\t\tunder the argument directory.";
  30
  31 int
  32 parse_mode(
  33  const char *   s
  34 ,mode_t *               or
  35 ,mode_t *               and
  36 ,int *                  group_execute)
  37 {
  38         /* [ugoa]{+|-|=}[rwxstl] */
  39         mode_t  mode = 0;
  40         mode_t  groups = S_ISVTX;
  41         char    type;
  42         char    c;
  43
  44         do {
  45                 for ( ; ; ) {
  46                         switch ( c = *s++ ) {
  47                         case '\0':
  48                                 return -1;
  49                         case 'u':
  50                                 groups |= S_ISUID|S_IRWXU;
  51                                 continue;
  52                         case 'g':
  53                                 groups |= S_ISGID|S_IRWXG;
  54                                 continue;
  55                         case 'o':
  56                                 groups |= S_IRWXO;
  57                                 continue;
  58                         case 'a':
  59                                 groups |= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
  60                                 continue;
  61                         case '+':
  62                         case '=':
  63                         case '-':
  64                                 type = c;
  65                                 if ( groups == S_ISVTX ) /* The default is "all" */
  66                                         groups |= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
  67                                 break;
  68                         default:
  69                                 if ( c >= '0' && c <= '7' && mode == 0 && groups == S_ISVTX ) {
  70                                         *and = 0;
  71                                         *or = strtol(--s, 0, 010);
  72                                         return 0;
  73                                 }
  74                                 else
  75                                         return -1;
  76                         }
  77                         break;
  78                 }
  79
  80                 while ( (c = *s++) != '\0' ) {
  81                         switch ( c ) {
  82                         case ',':
  83                                 break;
  84                         case 'r':
  85                                 mode |= S_IRUSR|S_IRGRP|S_IROTH;
  86                                 continue;
  87                         case 'w':
  88                                 mode |= S_IWUSR|S_IWGRP|S_IWOTH;
  89                                 continue;
  90                         case 'x':
  91                                 mode |= S_IXUSR|S_IXGRP|S_IXOTH;
  92                                 continue;
  93                         case 's':
  94                                 if ( group_execute != 0 && (groups & S_IRWXG) ) {
  95                                         if ( *group_execute < 0 )
  96                                                 return -1;
  97                                         if ( type != '-' ) {
  98                                                 mode |= S_IXGRP;
  99                                                 *group_execute = 1;
 100                                         }
 101                                 }
 102                                 mode |= S_ISUID|S_ISGID;
 103                                 continue;
 104                         case 'l':
 105                                 if ( *group_execute > 0 )
 106                                         return -1;
 107                                 if ( type != '-' ) {
 108                                         *and &= ~S_IXGRP;
 109                                         *group_execute = -1;
 110                                 }
 111                                 mode |= S_ISGID;
 112                                 groups |= S_ISGID;
 113                                 continue;
 114                         case 't':
 115                                 mode |= S_ISVTX;
 116                                 continue;
 117                         default:
 118                                 return -1;
 119                         }
 120                         break;
 121                 }
 122                 switch ( type ) {
 123                 case '=':
 124                         *and &= ~(groups);
 125                         /* fall through */
 126                 case '+':
 127                         *or |= mode & groups;
 128                         break;
 129                 case '-':
 130                         *and &= ~(mode & groups);
 131                         *or &= *and;
 132                         break;
 133                 }
 134         } while ( c == ',' );
 135         return 0;
 136 }
 137
 138 extern int
 139 chmod_main(struct FileInfo * i, int argc, char * * argv)
 140 {
 141         i->andWithMode = S_ISVTX|S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
 142         i->orWithMode = 0;
 143
 144         while ( argc >= 3 ) {
 145                 if ( parse_mode(argv[1], &i->orWithMode, &i->andWithMode, 0)
 146                  == 0 ) {
 147                         argc--;
 148                         argv++;
 149                 }
 150                 else if ( strcmp(argv[1], "-R") == 0 ) {
 151                         i->recursive = 1;
 152                         argc--;
 153                         argv++;
 154                 }
 155                 else
 156                         break;
 157         }
 158
 159         i->changeMode = 1;
 160         i->complainInPostProcess = 1;
 161
 162         return monadic_main(i, argc, argv);
 163 }