options: added -h --help

1 files changed, 31 insertions, 16 deletions

diff --git a/src/options.c b/src/options.c
index e60d4a2..5d7aaaa 100644
--- a/src/options.c
+++ b/src/options.c
@@ -5,6 +5,7 @@
  * vim:ts=4:sw=4:expandtab
  */
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <getopt.h>
 #include <stdbool.h>
@@ -17,6 +18,7 @@
 
 /* === GLOBAL VARIABLES === */
 struct option long_options[] = {
+    { "help", no_argument, 0, 0 },
     { "long-timestamp", no_argument, 0, 0 },
     { "reverse-sort", no_argument, 0, 0 },
     { "show-hidden-entries", no_argument, 0, 0 },
@@ -37,7 +39,7 @@ bool option_timestamp_long = false;
  */
 char option_time_field = 'm';
 
-
+char *exec_name;
 
 /* === IMPLEMENTATION === */
 
@@ -45,15 +47,17 @@ void usage(char *executable) {
     fprintf(stderr, "Call: %s OPTIONS path_to_open\n", executable);
     fprintf(stderr, "\nOPTIONS are\n");
     /* long name, short name, optional argument, explanation */
-    fprintf(stderr, " %-25s %2s %10s %s\n", "--long-timestamp", "-t", "",
+    fprintf(stderr, " %-25s %2s %10s   %s\n", "--help", "-h", "",
+            "Show this message and exit");
+    fprintf(stderr, " %-25s %2s %10s   %s\n", "--long-timestamp", "-t", "",
             "Print timestamp in long form yyyymmdd HH:MM:SS ZONE");
-    fprintf(stderr, " %-25s %2s %10s %s\n", "--reverse-sort", "", "",
+    fprintf(stderr, " %-25s %2s %10s   %s\n", "--reverse-sort", "", "",
             "Sort reversed");
-    fprintf(stderr, " %-25s %2s %10s %s\n", "--show-hidden-entries", "-v", "",
+    fprintf(stderr, " %-25s %2s %10s   %s\n", "--show-hidden-entries", "-v", "",
             "Show hidden entries in the directory");
-    fprintf(stderr, " %-25s %2s %10s %s\n", "--sort-by", "", "size|time",
-            "Sort either by time or size");
-    fprintf(stderr, " %-25s %2s %10s %s\n", "--time-field", "", "a|c|m",
+    fprintf(stderr, " %-25s %2s %10s   %s\n", "--sort-by", "", "size|time",
+            "Sort either by size or time");
+    fprintf(stderr, " %-25s %2s %10s   %s\n", "--time-field", "", "a|c|m",
             "Sort by (a)ccess, (c)hange or (m)odification time. Default: m");
 }
 
@@ -67,12 +71,12 @@ void set_option(const char *option_name, char *option_argument) {
         return;
 
     /* options WITHOUT arguments */
-    if (strcmp(option_name, "show-hidden-entries") == 0) {
-        option_show_hidden_entries = true;
-        return;
+    if (strcmp("help", option_name) == 0) {
+        usage(exec_name);
+        exit(EXIT_SUCCESS);
     }
 
-    if (strcmp(option_name, "long-timestamp") == 0) {
+    if (strcmp("long-timestamp", option_name) == 0) {
         option_timestamp_long = true;
         return;
     }
@@ -82,14 +86,19 @@ void set_option(const char *option_name, char *option_argument) {
         return;
     }
 
+    if (strcmp("show-hidden-entries", option_name) == 0) {
+        option_show_hidden_entries = true;
+        return;
+    }
+
     /* options WITH arguments */
     if (option_argument == NULL || option_argument[0] == '\0') {
         LOGERR("ERROR: option_name %s with missing option_argument\n",
                 option_name);
-        return;
+        exit(EXIT_FAILURE);
     }
 
-    if (strcmp(option_name, "sort-by") == 0) {
+    if (strcmp("sort-by", option_name) == 0) {
         if (strncmp("size", option_argument, 4) == 0) {
             option_sort_type = SORT_BY_SIZE;
         } else if (strncmp("time", option_argument, 4) == 0) {
@@ -101,7 +110,7 @@ void set_option(const char *option_name, char *option_argument) {
         return;
     }
 
-    if (strcmp(option_name, "time-field") == 0) {
+    if (strcmp("time-field", option_name) == 0) {
         switch (option_argument[0]) {
             case 'a':
                 option_time_field = 'a';
@@ -128,10 +137,12 @@ void set_option(const char *option_name, char *option_argument) {
 
 int parse_arguments(int argc, char **argv) {
     int c = 0, index;
+    /* exec_name is a file internal global variable for --help in set_option() */
+    exec_name = argv[0];
 
     while(1) {
         index = 0;
-        c = getopt_long(argc, argv, "tv", long_options, &index);
+        c = getopt_long(argc, argv, "htv", long_options, &index);
 
         if (c == -1) {
             break;
@@ -141,6 +152,9 @@ int parse_arguments(int argc, char **argv) {
             case 0:
                 set_option(long_options[index].name, optarg);
                 break;
+            case 'h':
+                usage(exec_name);
+                exit(EXIT_SUCCESS);
             case 't':
                 option_timestamp_long = true;
                 break;
@@ -151,7 +165,8 @@ int parse_arguments(int argc, char **argv) {
                 break;
             default:
                 LOGERR("ERROR: unrecognized option 0x%02X '%c'\n", c, c);
-                break;
+                usage(exec_name);
+                exit(EXIT_FAILURE);
         }
     }