shithub: orca

Info  •  Files  •  Log  •  Branches

Add better usage/help options to cli

--- a/cli_main.c

+++ b/cli_main.c

@@ -3,8 +3,21 @@

 #include "sim.h"

 #include <getopt.h>

+static void usage() {

+  // clang-format off

+  fprintf(stderr,

+      "Usage: orca [options] infile\n\n"

+      "Options:\n"

+      "    -t <number>   Number of timesteps to simulate.\n"

+      "                  Must be 0 or a positive integer.\n"

+      "                  Default: 1\n"

+      "    -h or --help  Print this message and exit.\n"

+      );

+  // clang-format on

+}

+

 int main(int argc, char** argv) {

-  static struct option cli_options[] = {{"time", required_argument, 0, 't'},

+  static struct option cli_options[] = {{"help", no_argument, 0, 'h'},

                                         {NULL, 0, NULL, 0}};

   char* input_file = NULL;

@@ -11,7 +24,7 @@

   int ticks = 1;

   for (;;) {

-    int c = getopt_long(argc, argv, "t:", cli_options, NULL);

+    int c = getopt_long(argc, argv, "t:h", cli_options, NULL);

     if (c == -1)

       break;

     switch (c) {

@@ -18,11 +31,18 @@

     case 't':

       ticks = atoi(optarg);

       if (ticks == 0 && strcmp(optarg, "0")) {

-        fprintf(stderr, "Bad time argument %s\n", optarg);

+        fprintf(stderr,

+                "Bad timestep argument %s.\n"

+                "Must be 0 or a positive integer.\n",

+                optarg);

         return 1;

       }

       break;

+    case 'h':

+      usage();

+      return 1;

     case '?':

+      usage();

       return 1;

     }

   }

@@ -36,9 +56,11 @@

   if (input_file == NULL) {

     fprintf(stderr, "No input file\n");

+    usage();

     return 1;

   }

   if (ticks < 0) {

+    usage();

     fprintf(stderr, "Time must be >= 0\n");

     return 1;

   }