Parse a config file. Not used for anything yet.
[cubemap] / cubemap.cpp
index ed615a876574a8334757bd226529f58814e3ef70..3f136aa09e23f956d76747149b0ce47c4a8a9bb5 100644 (file)
@@ -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);