commands/which/which.c

   1 /* which - search paths for executable */
   2
   3 #define DELIMITER ':'
   4
   5 #include <sys/types.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9 #include <stdio.h>
  10
  11 int main(int argc, char **argv);
  12
  13 int main(ac, av)
  14 int ac;
  15 char **av;
  16 {
  17   char *path, *cp;
  18   char buf[400];
  19   char prog[400];
  20   char patbuf[512];
  21   int quit, none;
  22   int excode = 0;
  23
  24   if (ac < 2) {
  25         fprintf(stderr, "Usage: %s cmd [cmd, ..]\n", *av);
  26         exit(1);
  27   }
  28   av[ac] = 0;
  29   for (av++; *av; av++) {
  30
  31         quit = 0;
  32         none = 1;
  33         if ((path = getenv("PATH")) == NULL) {
  34                 fprintf(stderr, "Null path.\n");
  35                 exit(0);
  36         }
  37         strcpy(patbuf, path);
  38         path = patbuf;
  39         cp = path;
  40
  41         while (1) {
  42                 cp = strchr(path, DELIMITER);
  43                 if (cp == NULL)
  44                         quit++;
  45                 else
  46                         *cp = '\0';
  47
  48                 if (strcmp(path, "") == 0 && quit == 0) {
  49                         sprintf(buf, "%s./%s", path, *av);
  50                 } else
  51                         sprintf(buf, "%s/%s", path, *av);
  52
  53                 /* Fprintf(stderr,"Trying %s, path %s\n",buf,path); */
  54
  55                 path = ++cp;
  56
  57                 if (access(buf, 1) == 0) {
  58                         printf("%s\n", buf);
  59                         none = 0;
  60                 }
  61                 sprintf(prog, "%s.%s", buf, "prg");
  62                 if (access(prog, 1) == 0) {
  63                         printf("%s\n", prog);
  64                         none = 0;
  65                 }
  66                 sprintf(prog, "%s.%s", buf, "ttp");
  67                 if (access(prog, 1) == 0) {
  68                         printf("%s\n", prog);
  69                         none = 0;
  70                 }
  71                 sprintf(prog, "%s.%s", buf, "tos");
  72                 if (access(prog, 1) == 0) {
  73                         printf("%s\n", prog);
  74                         none = 0;
  75                 }
  76                 if (quit) {
  77                         if (none) {
  78                                 fprintf(stderr, "No %s in %s\n", *av, getenv("PATH"));
  79                                 excode = 1;
  80                         }
  81                         break;
  82                 }
  83         }
  84   }
  85   return(excode);
  86 }