mkdir and rmdir basic implementation

ml_io.cpp

@@ -1,6 +1,7 @@
 
 #include "ml_io.h"
 
+#include <cstring>
 #include <dirent.h>
 #include <unistd.h>
 #include <sys/stat.h>
@@ -65,12 +66,22 @@ bool is_path_dir(const std::string &path) {
 	return (bool) S_ISDIR(buf.st_mode);
 }
 
-int mk_path_dir(const std::string &path) {
-	return ::mkdir(path.c_str(), 0755);
+bool mk_path_dir(const std::string &path) {
+	auto r = ::mkdir(path.c_str(), 0755);
+	if (r == -1) {
+		std::string err_msg = std::strerror(errno);
+		std::cerr << "mkdir failed: " << std::strerror(errno) << std::endl;
+	}
+	return r == 0;
 }
 
-int rm_path_dir(const std::string &path) {
-	return ::rmdir(path.c_str());
+bool rm_path_dir(const std::string &path) {
+	auto r = ::rmdir(path.c_str());
+	if (r == -1) {
+		std::string err_msg = std::strerror(errno);
+		std::cerr << "rmdir failed: " << std::strerror(errno) << std::endl;
+	}
+	return r == 0;
 }
 
 MlValue exec_system_cmd(const std::string &cmd) {