From 6b4c7eecb5910b35ac61452cd5515ff1ee03d1de Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Sun, 7 Apr 2013 15:33:37 +0200
Subject: [PATCH] Parse a config file. Not used for anything yet.

---
 cubemap.cpp | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 91 insertions(+), 4 deletions(-)

diff --git a/cubemap.cpp b/cubemap.cpp
index ed615a8..3f136aa 100644
--- a/cubemap.cpp
+++ b/cubemap.cpp
@@ -11,6 +11,7 @@
 #include <sys/epoll.h>
 #include <signal.h>
 #include <errno.h>
+#include <ctype.h>
 #include <vector>
 #include <string>
 #include <map>
@@ -171,16 +172,102 @@ CubemapStateProto read_tempfile(int state_fd)
 	return state;
 }
 
+// Split a line on whitespace, e.g. "foo  bar baz" -> {"foo", "bar", "baz"}.
+vector<string> split_tokens(const string &line)
+{
+	vector<string> ret;
+	string current_token;
+
+	for (size_t i = 0; i < line.size(); ++i) {
+		if (isspace(line[i])) {
+			if (!current_token.empty()) {
+				ret.push_back(current_token);
+			}
+			current_token.clear();
+		} else {
+			current_token.push_back(line[i]);
+		}
+	}
+	if (!current_token.empty()) {
+		ret.push_back(current_token);
+	}
+	return ret;
+}
+
+struct ConfigLine {
+	string keyword;
+	vector<string> arguments;
+	map<string, string> parameters;
+};
+
+// Parse the configuration file.
+vector<ConfigLine> parse_config(const string &filename)
+{
+	vector<ConfigLine> ret;
+
+	FILE *fp = fopen(filename.c_str(), "r");
+	if (fp == NULL) {
+		perror(filename.c_str());
+		exit(1);
+	}
+
+	char buf[4096];
+	while (!feof(fp)) {
+		if (fgets(buf, sizeof(buf), fp) == NULL) {
+			break;
+		}
+
+		// Chop off the string at the first #, \r or \n.
+		buf[strcspn(buf, "#\r\n")] = 0;
+
+		// Remove all whitespace from the end of the string.
+		size_t len = strlen(buf);
+		while (len > 0 && isspace(buf[len - 1])) {
+			buf[--len] = 0;
+		}
+
+		// If the line is now all blank, ignore it.
+		if (len == 0) {
+			continue;
+		}
+
+		vector<string> tokens = split_tokens(buf);
+		assert(!tokens.empty());
+		
+		ConfigLine line;
+		line.keyword = tokens[0];
+
+		for (size_t i = 1; i < tokens.size(); ++i) {
+			// foo=bar is a parameter; anything else is an argument.
+			size_t equals_pos = tokens[i].find_first_of('=');
+			if (equals_pos == string::npos) {
+				line.arguments.push_back(tokens[i]);
+			} else {
+				string key = tokens[i].substr(0, equals_pos);
+				string value = tokens[i].substr(equals_pos + 1, string::npos);
+				line.parameters.insert(make_pair(key, value));
+			}
+		}
+
+		ret.push_back(line);
+	}
+
+	fclose(fp);
+}
+
 int main(int argc, char **argv)
 {
 	fprintf(stderr, "\nCubemap starting.\n");
-		
+
+	string config_filename = (argc == 1) ? "cubemap.config" : argv[1];
+	vector<ConfigLine> config = parse_config(config_filename);
+
 	servers = new Server[NUM_SERVERS];
 
 	int server_sock;
-	if (argc == 3 && strcmp(argv[1], "-state") == 0) {
+	if (argc == 4 && strcmp(argv[2], "-state") == 0) {
 		fprintf(stderr, "Deserializing state from previous process... ");
-		int state_fd = atoi(argv[2]);
+		int state_fd = atoi(argv[3]);
 		CubemapStateProto loaded_state = read_tempfile(state_fd);
 
 		// Deserialize the streams.
@@ -250,7 +337,7 @@ int main(int argc, char **argv)
 	sprintf(buf, "%d", state_fd);
 
 	for ( ;; ) {
-		execlp(argv[0], argv[0], "-state", buf, NULL);
+		execlp(argv[0], argv[0], config_filename.c_str(), "-state", buf, NULL);
 		perror("execlp");
 		fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 		usleep(200000);
-- 
2.39.2