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[~andy/sfvlug] / c / src / opts.c

diff --git a/c/src/opts.c b/c/src/opts.c
new file mode 100644 (file)
index 0000000..9fc0ae1
--- /dev/null
+++ b/c/src/opts.c
@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+/* Options */
+static int   opt_verbose  = 0;
+static char *opt_greeting = "Hello";
+static char *opt_name     = "World";
+
+/* Parsing */
+static char *short_options = "hvg:n:";
+
+static struct option long_options[] = {
+       {"help",     0, NULL, 'h'},
+       {"verbose",  0, NULL, 'v'},
+       {"greeting", 1, NULL, 'g'},
+       {"name",     1, NULL, 'n'},
+};
+
+/* Show usage information */
+static void usage(int status)
+{
+       printf("opts -[OPTIONS]\n");
+       printf("\n");
+       printf("Options:\n");
+       printf("  -h,--help          Show usage information\n");
+       printf("  -v,--verbose       Print debug output messages\n");
+       printf("  -n,--greeting=STR  Use the given greeting\n");
+       printf("  -n,--name=NAME     Greet the given person\n");
+       exit(status);
+}
+
+/* Parse command line arguments */
+static void parse(int argc, char **argv)
+{
+       while (1) {
+               int c = getopt_long(argc, argv,
+                               short_options, long_options, 0);
+               if (c == -1)
+                       break;
+               switch (c) {
+                       case 'h': usage(0);               break;
+                       case 'v': opt_verbose   = 1;      break;
+                       case 'g': opt_greeting  = optarg; break;
+                       case 'n': opt_name      = optarg; break;
+                       default:  usage(1);               break;
+               }
+       }
+       if (argc != optind)
+               usage(1);
+
+       if (opt_verbose) {
+               printf("Options:\n");
+               printf("  verbose  = %d\n", opt_verbose);
+               printf("  greeting = %s\n", opt_greeting);
+               printf("  name     = %s\n", opt_name);
+               printf("\n");
+       }
+}
+
+/* Main entry point */
+int main(int argc, char **argv)
+{
+       parse(argc, argv);
+       printf("%s, %s\n", opt_greeting, opt_name);
+       return 0;
+}