cli: header with extra option implementations

For now just one, `struct cli_opt_data_size`.

1 files changed, 79 insertions, 0 deletions

diff --git a/cli/cli-opts.h b/cli/cli-opts.h
new file mode 100644
index 0000000..4a94bcc
--- /dev/null
+++ b/cli/cli-opts.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+/**
+ * cli-opts.h - Extra cli_opt implementations for cli.h
+ *
+ * Copyright (c) 2025 - Yaroslav de la Peña Smirnov
+ */
+#ifndef CLI_OPTS_H
+#define CLI_OPTS_H
+#include "cli.h"
+#include <ctype.h>
+
+/**
+ * struct cli_opt_data_size - an option that represents data size in bytes.
+ * @opt:	parent class.
+ * @bytes:	the amount given by the user in bytes.
+ *
+ * This CLI option can parse units in bytes, KiB, MiB, GiB, TiB. By giving the
+ * number a suffix, it multiplies the number by the equivalent in bytes. E.g.
+ * `1K` == `1024`.
+ */
+struct cli_opt_data_size {
+	struct cli_opt opt;
+	uint64_t	   bytes;
+};
+
+#define CLI_OPT_DATA_SIZE(name, sh, ln, dsc)   \
+	struct cli_opt_data_size name = {          \
+		.opt =                                 \
+			{                                  \
+				.type = CLI_OT_VALUE,          \
+				.shor = sh,                    \
+				.lon  = ln,                    \
+				.desc = dsc,                   \
+				.set  = cli_opt_data_size_set, \
+			},                                 \
+	}
+
+int cli_opt_data_size_set(struct cli_opt *self, const char *val)
+{
+	struct cli_opt_data_size *opt =
+		container_of(self, struct cli_opt_data_size, opt);
+
+	char *endptr		   = NULL;
+	errno				   = 0;
+	unsigned long long num = strtoull(val, &endptr, 10);
+	if (errno != 0)
+		goto invalid;
+
+	if (endptr && *endptr != '\0') {
+		switch (toupper(*endptr)) {
+		case 'K':
+			opt->bytes = num <<= 10;
+			break;
+		case 'M':
+			opt->bytes = num <<= 20;
+			break;
+		case 'G':
+			opt->bytes = num <<= 30;
+			break;
+		case 'T':
+			opt->bytes = num <<= 40;
+			break;
+		default:
+			goto invalid;
+		}
+	} else {
+		opt->bytes = num;
+	}
+
+	return CLI_RC_OK;
+invalid:
+	fprintf(stderr,
+			"invalid value \"%s\", expected a number optionally followed "
+			"by a multiplicative suffix (K, M, G, T).",
+			val);
+	return CLI_RC_ERR;
+}
+
+#endif /* CLI_OPTS_H */