Refactor: arguments specify font pattern

main.cpp

@@ -15,27 +15,38 @@ FcChar8 * toFcChar8(const char * sc) {
     return result;
 }
 
-int main() {
+void print_help(const string & program_name) {
+    cout << "Usage: " << program_name << "\"Font Pattern\"" << endl;
+    cout << "Note: better to quote all your pattern," << endl;
+    cout << "  since bash will split them into multi word if not" << endl;
+}
+
+int main(int argc, char ** argv) {
     FcPattern * fcp = FcPatternCreate();
 
-    string line;
-    getline(cin, line);
+    if (argc != 2) {
+        cout << "Wrong usage!" << endl;
+        print_help(argv[0]);
 
-    line += ',';
-    size_t l = 0, r = line.find(",", 0);
+        exit(-1);
+    }
+
+    string patterns = argv[1];
+
+    patterns += ',';
+    size_t l = 0, r = patterns.find(",", 0);
     while (r != string::npos) {
-        FcChar8 * queryName = toFcChar8(line.substr(l, r - l).c_str());
+        FcChar8 * queryName = toFcChar8(patterns.substr(l, r - l).c_str());
         FcPatternAddString(fcp, FC_FAMILY, queryName);
         delete[] queryName;
 
         l = r + 1;
-        r = line.find(",", l + 1);
+        r = patterns.find(",", l + 1);
     }
 
     FcChar8 * resultName = nullptr;
     FcConfigSubstitute(nullptr, fcp, FcMatchPattern);
 
-    cout << "========================" << endl;
     for (int i = 0; FcPatternGetString(fcp, FC_FAMILY, i, &resultName) == FcResultMatch; ++i) {
         cout << resultName << endl;
     }