sendmail.c

   1 #include <errno.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6
   7
   8 static void usage(char* arg0) {
   9     puts("A wrapper script for smailq that mimics sendmail.\n"
  10          "USAGE:\n");
  11     printf("  %s [OPTIONS] [recipient ...]\n", arg0);
  12     printf("  %s -bp\n", arg0);
  13     puts("\n"
  14          "OPTIONS:\n"
  15          "  -bp\n"
  16          "     Calls `smailq --list`\n"
  17          "\n"
  18          "  -h\n"
  19          "     Prints this help text\n"
  20          "\n"
  21          "  [OPTIONS] [recipient ...]\n"
  22          "     Calls `smailq --send -- [OPTIONS] [recipient ...]`.\n"
  23          "     It passes all options as MSA options to smailq.\n");
  24 }
  25
  26 int main(int argc, char* argv[]) {
  27     if (argc == 1) {
  28         fputs("No arguments given.\n", stderr);
  29         usage(argv[0]);
  30         return EINVAL;
  31     }
  32
  33     if (strcmp(argv[1], "-h") == 0) {
  34         usage(argv[0]);
  35         return EXIT_SUCCESS;
  36     }
  37
  38     if (strcmp(argv[1], "-bp") == 0) {
  39         execlp("smailq", "smailq", "list", NULL);
  40         perror("Error calling smailq --list");
  41         return EXIT_FAILURE;
  42     }
  43
  44     /* We have to add two more arguments: -- --send */
  45     char** newargv = malloc((argc+2)*sizeof(char*));
  46     if (newargv == NULL) {
  47         perror(NULL);
  48         return EXIT_FAILURE;
  49     }
  50
  51     /* Fill in the arguments for smailq. Note that argv[argc] is NULL and
  52      * newargv must be termined by a NULL pointer for execvp(). */
  53     newargv[0] = "smailq";
  54     newargv[1] = "--send";
  55     newargv[2] = "--";
  56     for (int i=1; i <= argc; ++i)
  57         newargv[2+i] = argv[i];
  58
  59     execvp("smailq", newargv);
  60     perror("Error calling smailq --list");
  61     free(newargv);
  62     return EXIT_FAILURE;
  63 }