Some improvements to random_word

[cmccabe-bin] / random_word.c

diff --git a/random-word.c b/random_word.c
similarity index 69%
rename from random-word.c
rename to random_word.c
index d751d06..f29bc7d 100644 (file)
--- a/random-word.c
+++ b/random_word.c
@@ -3,8 +3,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/time.h>
+#include <unistd.h>
 
-#define DICT "/usr/share/dict/linux.words"
+#define DEFAULT_DICT_PATH "/usr/share/dict/linux.words"
 #define STARTING_SZ 8192
 #define MAX_ARRAY_SZ 1073741824
 
@@ -86,21 +87,54 @@ static const char* choose_random_word(struct dict *dict)
        return dict->words[choice];
 }
 
-int main(void)
+static void print_usage(char *program_name)
+{
+       printf("%s: prints a random word from a linebreak-delimited file.\n",
+              program_name);
+       printf("options:\n");
+       printf("\t-d: the dictionary file to use.  Default: %s.\n",
+              DEFAULT_DICT_PATH);
+       printf("\t-h: this help message.\n");
+}
+
+static void parse_args(char **argv, int argc, char **dict_path)
+{
+       char c;
+       *dict_path = DEFAULT_DICT_PATH;
+       opterr = 0;
+       while ((c = getopt(argc, argv, "d:h")) != -1) {
+               switch (c) {
+               case 'd':
+                       *dict_path = optarg;
+                       break;
+               case 'h':
+                       print_usage(argv[0]);
+                       exit(0);
+                       break;
+               default:
+                       fprintf (stderr, "Argument parsing error.\n");
+                       exit(1);
+               }
+       }
+}
+
+int main(int argc, char **argv)
 {
        FILE *fp;
+       char *dict_path;
        const char *word;
        struct dict *dict;
        struct timeval tv;
 
+       parse_args(argv, argc, &dict_path);
        gettimeofday(&tv, NULL);
        srandom(tv.tv_usec * tv.tv_sec);
 
-       fp = fopen(DICT, "r");
+       fp = fopen(dict_path, "r");
        if (! fp) {
                int err = errno;
                fprintf(stderr, "failed to open %s: %s (%d).\n",
-                       DICT, strerror(err), err);
+                       dict_path, strerror(err), err);
                return 1;
        }
        dict = read_dict(fp);