commands/simple/mkfifo.c

   1 /* mkfifo - Make FIFO special files             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 #include <sys/types.h>
  10 #include <stdlib.h>
  11 #include <sys/stat.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <minix/minlib.h>
  15 #include <stdio.h>
  16
  17 #define USR_MODES (S_ISUID|S_IRWXU)
  18 #define GRP_MODES (S_ISGID|S_IRWXG)
  19 #define EXE_MODES (S_IXUSR|S_IXGRP|S_IXOTH)
  20 #ifdef S_ISVTX
  21 #define ALL_MODES (USR_MODES|GRP_MODES|S_IRWXO|S_ISVTX)
  22 #else
  23 #define ALL_MODES (USR_MODES|GRP_MODES|S_IRWXO)
  24 #endif
  25 #define DEFAULT_MODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
  26
  27
  28 /* Global u_mask needed in changemode.h */
  29 mode_t u_mask;
  30
  31 _PROTOTYPE(int main, (int argc, char **argv));
  32 _PROTOTYPE(mode_t parsemode, (char *symbolic, mode_t oldmode));
  33 _PROTOTYPE(void usage, (void));
  34
  35 /* Parse a P1003.2 4.7.7-conformant symbolic mode. */
  36 mode_t parsemode(char *symbolic, mode_t oldmode)
  37 {
  38   mode_t who, mask, newmode, tmpmask;
  39   char action;
  40
  41   newmode = oldmode & ALL_MODES;
  42   while (*symbolic) {
  43         who = 0;
  44         for (; *symbolic; symbolic++) {
  45                 if (*symbolic == 'a') {
  46                         who |= ALL_MODES;
  47                         continue;
  48                 }
  49                 if (*symbolic == 'u') {
  50                         who |= USR_MODES;
  51                         continue;
  52                 }
  53                 if (*symbolic == 'g') {
  54                         who |= GRP_MODES;
  55                         continue;
  56                 }
  57                 if (*symbolic == 'o') {
  58                         who |= S_IRWXO;
  59                         continue;
  60                 }
  61                 break;
  62         }
  63         if (!*symbolic || *symbolic == ',') usage();
  64         while (*symbolic) {
  65                 if (*symbolic == ',') break;
  66                 switch (*symbolic) {
  67                     default:
  68                         usage();
  69                     case '+':
  70                     case '-':
  71                     case '=':   action = *symbolic++;
  72                 }
  73                 mask = 0;
  74                 for (; *symbolic; symbolic++) {
  75                         if (*symbolic == 'u') {
  76                                 tmpmask = newmode & S_IRWXU;
  77                                 mask |= tmpmask | (tmpmask << 3) | (tmpmask << 6);
  78                                 symbolic++;
  79                                 break;
  80                         }
  81                         if (*symbolic == 'g') {
  82                                 tmpmask = newmode & S_IRWXG;
  83                                 mask |= tmpmask | (tmpmask >> 3) | (tmpmask << 3);
  84                                 symbolic++;
  85                                 break;
  86                         }
  87                         if (*symbolic == 'o') {
  88                                 tmpmask = newmode & S_IRWXO;
  89                                 mask |= tmpmask | (tmpmask >> 3) | (tmpmask >> 6);
  90                                 symbolic++;
  91                                 break;
  92                         }
  93                         if (*symbolic == 'r') {
  94                                 mask |= S_IRUSR | S_IRGRP | S_IROTH;
  95                                 continue;
  96                         }
  97                         if (*symbolic == 'w') {
  98                                 mask |= S_IWUSR | S_IWGRP | S_IWOTH;
  99                                 continue;
 100                         }
 101                         if (*symbolic == 'x') {
 102                                 mask |= EXE_MODES;
 103                                 continue;
 104                         }
 105                         if (*symbolic == 's') {
 106                                 mask |= S_ISUID | S_ISGID;
 107                                 continue;
 108                         }
 109                         if (*symbolic == 'X') {
 110                                 if (S_ISDIR(oldmode) || (oldmode & EXE_MODES))
 111                                         mask |= EXE_MODES;
 112                                 continue;
 113                         }
 114 #ifdef S_ISVTX
 115                         if (*symbolic == 't') {
 116                                 mask |= S_ISVTX;
 117                                 who |= S_ISVTX;
 118                                 continue;
 119                         }
 120 #endif
 121                         break;
 122                 }
 123                 switch (action) {
 124                     case '=':
 125                         if (who)
 126                                 newmode &= ~who;
 127                         else
 128                                 newmode = 0;
 129                     case '+':
 130                         if (who)
 131                                 newmode |= who & mask;
 132                         else
 133                                 newmode |= mask & (~u_mask);
 134                         break;
 135                     case '-':
 136                         if (who)
 137                                 newmode &= ~(who & mask);
 138                         else
 139                                 newmode &= ~mask | u_mask;
 140                 }
 141         }
 142         if (*symbolic) symbolic++;
 143   }
 144   return(newmode);
 145 }
 146
 147
 148 /* Main module. Since only one option (-m mode) is allowed, there's no need
 149  * to include the whole getopt() stuff.
 150  */
 151 int main(argc, argv)
 152 int argc;
 153 char *argv[];
 154 {
 155   int errors = 0;
 156   char *symbolic;
 157
 158   if (argc > 2 && *argv[1] == '-' && strcmp(argv[1], "-m") != 0) usage();
 159   argc--;
 160   argv++;
 161   if (argc && strncmp(*argv, "-m", (size_t) 2) == 0) {
 162         argc--;
 163         if ((argv[0])[2])
 164                 symbolic = (*argv++) + 2;
 165         else {
 166                 if (!argc--) usage();
 167                 argv++;
 168                 symbolic = *argv++;
 169         }
 170         u_mask = umask(0);
 171         umask(u_mask);
 172   } else
 173         symbolic = (char *) 0;
 174
 175   if (!argc) usage();
 176   for (; argc--; argv++)
 177         if (mkfifo(*argv, DEFAULT_MODE)) {
 178                 perror(*argv);
 179                 errors = 1;
 180         } else if (symbolic && chmod(*argv, parsemode(symbolic, DEFAULT_MODE))) {
 181                 unlink(*argv);
 182                 perror(*argv);
 183                 errors = 1;
 184         }
 185   return(errors);
 186 }
 187
 188
 189 /* Posix command prototype. */
 190 void usage()
 191 {
 192   std_err("Usage: mkfifo [-m mode] file...\n");
 193   exit(1);
 194 }