1 files changed, 94 insertions, 0 deletions
diff --git a/cliflags.c b/cliflags.c
new file mode 100644
index 0000000..e3ff7f2
--- /dev/null
+++ b/cliflags.c
@@ -0,0 +1,94 @@
+/*-
+ * Copyright (c) 2026, Mr. Goblin
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
+ * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "cliflags.h"
+
+/* -f */
+struct bool_flag_val
+extract_bool_flag(char flagletter, int argc, char **argv)
+{
+	struct bool_flag_val res = {0};
+	char flagstr[3] = { '-', ' ', '\0' };
+	int i;
+	flagstr[1] = flagletter;
+	res.code = fvr_not_found;
+	res.data = 0;
+	for (i = 1; i < argc; i++) {
+		if (0 == strcmp(flagstr, argv[i])) {
+			res.code = fvr_ok;
+			res.data = 1;
+			break;
+		}
+	}
+	return res;
+}
+
+/* -f the_str */
+struct str_flag_val
+extract_str_flag(char flagletter, int argc, char **argv)
+{
+	struct str_flag_val res = {0};
+	char flagstr[3] = { '-', ' ', '\0' };
+	int i;
+	flagstr[1] = flagletter;
+	for (i = 1; i < argc; i++)
+		if (0 == strcmp(flagstr, argv[i]))
+			break;
+	if (argc <= i) {
+		res.code = fvr_not_found;
+	} else if (argc-1 == i) {
+		res.code = fvr_invalid;
+	} else {
+		res.code = fvr_ok;
+		res.data = argv[i+1];
+	}
+	return res;
+}
+
+/* -f number */
+struct int_flag_val
+extract_int_flag(char flagletter, int argc, char **argv)
+{
+	struct int_flag_val res;
+	struct str_flag_val strres =
+		extract_str_flag(flagletter, argc, argv);
+	char *endptr;
+	res.code = strres.code;
+	if (fvr_ok != res.code) {
+		return res;
+	}
+	res.data = strtol(strres.data, &endptr, 10);
+	if ('\0' != *endptr)
+		res.code = fvr_invalid;
+	return res;
+}