From 11b23c19f71a1dd4ea9916e71632ce251213dbb4 Mon Sep 17 00:00:00 2001
From: theflash <theflash AT sdf DOT lonestar DOT org>
Date: Tue, 1 Sep 2015 03:07:54 +0200
Subject: [PATCH] Implement argument parsing in zilasm. Patch by Jason Self.
 Thanks!

---
 zilasm/main.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 147 insertions(+), 1 deletion(-)

diff --git a/zilasm/main.c b/zilasm/main.c
index e8e9f7e..97c4558 100644
--- a/zilasm/main.c
+++ b/zilasm/main.c
@@ -2,6 +2,7 @@
  * main.c
  *
  * Copyright (C) 2015 Alexander Andrejevic <theflash AT sdf DOT lonestar DOT org>
+ * Copyright (C) 2015 Jason Self <j@jxself.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -17,10 +18,155 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>
  */
 
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <time.h>
+#include <ctype.h>
+
+#include "config.h"
+
+enum { ZVERSION = 11, ZORKID, ZSERIAL };
+
+static struct option const long_options[] =
+{
+    { "help",     no_argument,       NULL, 'h' },
+    { "version",  no_argument,       NULL, 'V' },
+    { "zversion", required_argument, NULL, ZVERSION },
+    { "zorkid",   required_argument, NULL, ZORKID   },
+    { "serial",   required_argument, NULL, ZSERIAL  },
+    { NULL, 0, NULL, 0 }
+};
+
+struct
+{
+    int  zversion;     /* 0 - 8   */
+    int  zorkid;       /* 0 - 255 */
+    char zserial[7];   /* YYMMDD  */
+} Config;
+
+void wrong_arg()
+{
+    fprintf(stderr, "Try `" PACKAGE_NAME " --help' for more information.\n");
+    exit(1);
+}
+
+void print_version()
+{
+    printf(PACKAGE_STRING "\n"
+           "License AGPLv3+: GNU AGPL version 3 or later\n"
+           "<http://gnu.org/licenses/agpl.html>\n"
+           "This is free software: you are free to change and redistribute it.\n"
+           "There is NO WARRANTY, to the extent permitted by law.\n"
+    );
+
+    exit(0);
+}
+
+void print_usage(int failed)
+{
+    printf("Usage: " PACKAGE_NAME " [OPTION...] [FILES...]\n"
+           "\n"
+           "--version  Display program version and exit\n"
+           "--help     Display this help\n"
+           "\n"
+           "--zversion (accepts numbers 1 - 8, defaults to 1 if not specified)\n"
+           "--zorkid   (accepts digits, defaults to 0 if not specified)\n"
+           "--serial   (six characters of ASCII, defaults to current date\n"
+           "            in the form YYMMDD if not specified)\n"
+    );
+
+    exit(failed);
+}
+
+void fill_zserial(void)
+{
+    time_t t;
+    struct tm *timeinfo;
+    time(&t);
+    timeinfo = localtime(&t);
+    strftime(Config.zserial, sizeof(Config.zserial), "%y%m%d", timeinfo);
+}
+
+void fill_config(void)
+{
+    Config.zversion = 1;
+    Config.zorkid   = 0;
+    fill_zserial();
+}
+
+void parse_intarg(int *dest, const char name[], int min, int max, int defval)
+{
+    if (!optarg)
+    {
+        *dest = defval;
+        return;
+    }
+
+    int n = atoi(optarg);
+    if (n >= min && n <= max)
+    {
+        *dest = n;
+        return;
+    }
+
+    fprintf(stderr, "Wrong %s value %s, must be integer between %d and %d\n",
+            name, optarg, min, max);
+    wrong_arg();
+}
+
+void parse_zserial(void)
+{
+    if (!optarg)
+    {
+        fill_zserial();
+        return;
+    }
+
+    size_t n = strlen(optarg);
+    if (n == sizeof(Config.zserial) - 1)
+    {
+        char *p = optarg;
+        while (*p && isdigit(*p)) p++;
+
+        if (!*p) /* ..optarg contains digits only? */
+        {
+            strncpy(Config.zserial, optarg, sizeof(Config.zserial));
+            return;
+        }
+    }
+
+    fprintf(stderr, "Wrong zserial value %s, must be 6 digits in yymmdd format\n", optarg);
+    wrong_arg();
+}
 
 int main(int argc, char *argv[], char *envp[])
 {
+    fill_config();
+
+    int opt = 0;
+    while ((opt = getopt_long(argc, argv, "hV", long_options, NULL)) != -1)
+    {
+        switch (opt)
+        {
+            case 'h'     : print_usage(0);
+            case 'V'     : print_version();
+            case ZVERSION: parse_intarg(&Config.zversion, "zversion", 1, 8,   1); break;
+            case ZORKID  : parse_intarg(&Config.zorkid,   "zorkid",   0, 255, 0); break;
+            case ZSERIAL : parse_zserial();  break;
+            default      : wrong_arg();
+        }
+    }
+
     // TODO: Everything :)
-    return EXIT_SUCCESS;
+
+    printf("Config:\n"
+           "- ZVersion: %d\n"
+           "- ZorkID:   %d\n"
+           "- ZSerial:  %s\n",
+           Config.zversion, Config.zorkid, Config.zserial
+    );
+
+    return 0;
 }
-- 
2.31.1