changes here, changes there

ml_io.cpp

@@ -23,6 +23,14 @@ std::string read_file_contents(const std::string &filename) {
 	return contents;
 }
 
+int write_file_contents(const std::string &filename, const std::string &content) {
+	std::ofstream f;
+	f.open(filename.c_str());
+	int result = (f << content) ? 1 : 0;
+	f.close();
+	return result;
+}
+
 MlValue list_dir(const std::string &path) {
 	std::vector<MlValue> entries;
 
@@ -50,13 +58,42 @@ bool is_path_dir(const std::string &path) {
 	return (bool) S_ISDIR(buf.st_mode);
 }
 
-int mk_dir(const std::string &path) {
+int mk_path_dir(const std::string &path) {
 	int r = ::mkdir(path.c_str(), 0755);
 	return r;
 }
 
-int rm_dir(const std::string &path) {
+int rm_path_dir(const std::string &path) {
 	int r = ::rmdir(path.c_str());
 	return r;
 }
 
+MlValue exec_system_cmd(const std::string &cmd) {
+	// TODO handle reading of stderr
+	// https://stackoverflow.com/questions/478898/how-do-i-execute-a-command-and-get-the-output-of-the-command-within-c-using-po
+	// https://jineshkj.wordpress.com/2006/12/22/how-to-capture-stdin-stdout-and-stderr-of-child-program/
+
+	std::string cmd_output;
+	int stat;
+	char buffer[128];
+	FILE *pipe = popen(cmd.c_str(), "r");
+	if (!pipe)
+		throw std::runtime_error("popen() failed!");
+	try {
+		while (!feof(pipe)) {
+			if (fgets(buffer, 128, pipe) != nullptr)
+				cmd_output += buffer;
+		}
+	} catch (...) {
+		stat = pclose(pipe);
+		throw;
+	}
+	stat = pclose(pipe);
+	int cmd_retval = WEXITSTATUS(stat);
+
+	// TODO add helper function for this
+	std::vector<MlValue> lst;
+	lst.push_back(MlValue(cmd_retval));
+	lst.push_back(MlValue::string(cmd_output));
+	return lst;
+}