utils: update date/size parsing, factor out format

And update tests

lib/utils/mu-utils-format.hh

@@ -0,0 +1,58 @@
+/*
+** Copyright (C) 2022 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
+**
+** This program is free software; you can redistribute it and/or modify it
+** under the terms of the GNU General Public License as published by the
+** Free Software Foundation; either version 3, or (at your option) any
+** later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software Foundation,
+** Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+**
+*/
+
+#ifndef MU_UTILS_FORMAT_HH__
+#define MU_UTILS_FORMAT_HH__
+
+namespace Mu {
+
+/**
+ * Quote & escape a string for " and \
+ *
+ * @param str a string
+ *
+ * @return quoted string
+ */
+std::string quote(const std::string& str);
+
+/**
+ * Format a string, printf style
+ *
+ * @param frm format string
+ * @param ... parameters
+ *
+ * @return a formatted string
+ */
+std::string format(const char* frm, ...) __attribute__((format(printf, 1, 2)));
+
+/**
+ * Format a string, printf style
+ *
+ * @param frm format string
+ * @param ... parameters
+ *
+ * @return a formatted string
+ */
+std::string vformat(const char* frm, va_list args) __attribute__((format(printf, 1, 0)));
+
+
+} // namepace Mu
+
+
+#endif /* MU_UTILS_FORMAT_HH__ */