source: trunk/minix/commands/simple/mkfifo.c@ 15

/* mkfifo - Make FIFO special files             Author: V. Archer */

/* Copyright 1991 by Vincent Archer
 *      You may freely redistribute this software, in source or binary
 *      form, provided that you do not alter this copyright mention in any
 *      way.
 */

#include <sys/types.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <minix/minlib.h>
#include <stdio.h>

#define USR_MODES (S_ISUID|S_IRWXU)
#define GRP_MODES (S_ISGID|S_IRWXG)
#define EXE_MODES (S_IXUSR|S_IXGRP|S_IXOTH)
#ifdef S_ISVTX
#define ALL_MODES (USR_MODES|GRP_MODES|S_IRWXO|S_ISVTX)
#else
#define ALL_MODES (USR_MODES|GRP_MODES|S_IRWXO)
#endif
#define DEFAULT_MODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)


/* Global u_mask needed in changemode.h */
mode_t u_mask;

_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(mode_t parsemode, (char *symbolic, mode_t oldmode));
_PROTOTYPE(void usage, (void));

/* Parse a P1003.2 4.7.7-conformant symbolic mode. */
mode_t parsemode(char *symbolic, mode_t oldmode)
{
  mode_t who, mask, newmode, tmpmask;
  char action;

  newmode = oldmode & ALL_MODES;
  while (*symbolic) {
        who = 0;
        for (; *symbolic; symbolic++) {
                if (*symbolic == 'a') {
                        who |= ALL_MODES;
                        continue;
                }
                if (*symbolic == 'u') {
                        who |= USR_MODES;
                        continue;
                }
                if (*symbolic == 'g') {
                        who |= GRP_MODES;
                        continue;
                }
                if (*symbolic == 'o') {
                        who |= S_IRWXO;
                        continue;
                }
                break;
        }
        if (!*symbolic || *symbolic == ',') usage();
        while (*symbolic) {
                if (*symbolic == ',') break;
                switch (*symbolic) {
                    default:
                        usage();
                    case '+':
                    case '-':
                    case '=':   action = *symbolic++;
                }
                mask = 0;
                for (; *symbolic; symbolic++) {
                        if (*symbolic == 'u') {
                                tmpmask = newmode & S_IRWXU;
                                mask |= tmpmask | (tmpmask << 3) | (tmpmask << 6);
                                symbolic++;
                                break;
                        }
                        if (*symbolic == 'g') {
                                tmpmask = newmode & S_IRWXG;
                                mask |= tmpmask | (tmpmask >> 3) | (tmpmask << 3);
                                symbolic++;
                                break;
                        }
                        if (*symbolic == 'o') {
                                tmpmask = newmode & S_IRWXO;
                                mask |= tmpmask | (tmpmask >> 3) | (tmpmask >> 6);
                                symbolic++;
                                break;
                        }
                        if (*symbolic == 'r') {
                                mask |= S_IRUSR | S_IRGRP | S_IROTH;
                                continue;
                        }
                        if (*symbolic == 'w') {
                                mask |= S_IWUSR | S_IWGRP | S_IWOTH;
                                continue;
                        }
                        if (*symbolic == 'x') {
                                mask |= EXE_MODES;
                                continue;
                        }
                        if (*symbolic == 's') {
                                mask |= S_ISUID | S_ISGID;
                                continue;
                        }
                        if (*symbolic == 'X') {
                                if (S_ISDIR(oldmode) || (oldmode & EXE_MODES))
                                        mask |= EXE_MODES;
                                continue;
                        }
#ifdef S_ISVTX
                        if (*symbolic == 't') {
                                mask |= S_ISVTX;
                                who |= S_ISVTX;
                                continue;
                        }
#endif
                        break;
                }
                switch (action) {
                    case '=':
                        if (who)
                                newmode &= ~who;
                        else
                                newmode = 0;
                    case '+':
                        if (who)
                                newmode |= who & mask;
                        else
                                newmode |= mask & (~u_mask);
                        break;
                    case '-':
                        if (who)
                                newmode &= ~(who & mask);
                        else
                                newmode &= ~mask | u_mask;
                }
        }
        if (*symbolic) symbolic++;
  }
  return(newmode);
}


/* Main module. Since only one option (-m mode) is allowed, there's no need
 * to include the whole getopt() stuff.
 */
int main(argc, argv)
int argc;
char *argv[];
{
  int errors = 0;
  char *symbolic;

  if (argc > 2 && *argv[1] == '-' && strcmp(argv[1], "-m") != 0) usage();
  argc--;
  argv++;
  if (argc && strncmp(*argv, "-m", (size_t) 2) == 0) {
        argc--;
        if ((argv[0])[2])
                symbolic = (*argv++) + 2;
        else {
                if (!argc--) usage();
                argv++;
                symbolic = *argv++;
        }
        u_mask = umask(0);
        umask(u_mask);
  } else
        symbolic = (char *) 0;

  if (!argc) usage();
  for (; argc--; argv++)
        if (mkfifo(*argv, DEFAULT_MODE)) {
                perror(*argv);
                errors = 1;
        } else if (symbolic && chmod(*argv, parsemode(symbolic, DEFAULT_MODE))) {
                unlink(*argv);
                perror(*argv);
                errors = 1;
        }
  return(errors);
}


/* Posix command prototype. */
void usage()
{
  std_err("Usage: mkfifo [-m mode] file...\n");
  exit(1);
}