src/minish-once.c

   1 #define _POSIX_C_SOURCE 200809L
   2
   3 #include <errno.h> // ENOMEM,errno
   4 #include <locale.h> // LC_ALL,setlocale
   5 #include <signal.h> // SIGHUP,raise
   6 #include <stdio.h> // ferror,fputs,getline,perror,ssize_t,stderr,stdin
   7 #include <stdlib.h> // EXIT_FAILURE,NULL,malloc,size_t
   8 #include <unistd.h> // execv
   9
  10 int main(void) {
  11         setlocale(LC_ALL, "");
  12         char* line = NULL;
  13         size_t size = 0u;
  14         ssize_t len = getline(&line, &size, stdin);
  15         if (len == -1) {
  16                 if (ferror(stdin)) {
  17                         perror("minish-once");
  18                 }
  19                 raise(SIGHUP);
  20                 return EXIT_FAILURE;
  21         }
  22         // NOTE len cannot be 0
  23         if (line[len - 1] == '\n') {
  24                 line[--len] = '\0';
  25         }
  26         size_t words = 1u;
  27         for (char* s = line; s < line + len; ++s) {
  28                 if (!*s) {
  29                         ++words;
  30                 }
  31         }
  32         char** const argv = malloc(words * sizeof(char*));
  33         if (!argv) {
  34                 errno = ENOMEM;
  35                 perror("minish-once: malloc()");
  36                 return EXIT_FAILURE;
  37         }
  38         argv[0] = line;
  39         size_t i = 1u;
  40         for (char* s = line; s < line + len; ++s) {
  41                 if (!*s) {
  42                         argv[i++] = s + 1;
  43                 }
  44         }
  45         argv[i] = NULL;
  46         execv(line, argv);
  47         fputs("minish-once: ", stderr);
  48         perror(line);
  49         return EXIT_FAILURE;
  50 }