1 files changed, 125 insertions, 0 deletions
diff --git a/lib/getopt.c b/lib/getopt.c
new file mode 100644
index 00000000000..8b4515dc196
--- /dev/null
+++ b/lib/getopt.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * getopt.c - a simple getopt(3) implementation. See getopt.h for explanation.
+ *
+ * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
+ * Copyright (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ */
+
+#define LOG_CATEGORY LOGC_CORE
+
+#include <common.h>
+#include <getopt.h>
+#include <log.h>
+
+void getopt_init_state(struct getopt_state *gs)
+{
+	gs->index = 1;
+	gs->arg_index = 1;
+}
+
+int __getopt(struct getopt_state *gs, int argc, char *const argv[],
+	     const char *optstring, bool silent)
+{
+	char curopt;   /* current option character */
+	const char *curoptp; /* pointer to the current option in optstring */
+
+	while (1) {
+		log_debug("arg_index: %d index: %d\n", gs->arg_index,
+			  gs->index);
+
+		/* `--` indicates the end of options */
+		if (gs->arg_index == 1 && argv[gs->index] &&
+		    !strcmp(argv[gs->index], "--")) {
+			gs->index++;
+			return -1;
+		}
+
+		/* Out of arguments */
+		if (gs->index >= argc)
+			return -1;
+
+		/* Can't parse non-options */
+		if (*argv[gs->index] != '-')
+			return -1;
+
+		/* We have found an option */
+		curopt = argv[gs->index][gs->arg_index];
+		if (curopt)
+			break;
+		/*
+		 * no more options in current argv[] element; try the next one
+		 */
+		gs->index++;
+		gs->arg_index = 1;
+	}
+
+	/* look up current option in optstring */
+	curoptp = strchr(optstring, curopt);
+
+	if (!curoptp) {
+		if (!silent)
+			printf("%s: invalid option -- %c\n", argv[0], curopt);
+		gs->opt = curopt;
+		gs->arg_index++;
+		return '?';
+	}
+
+	if (*(curoptp + 1) != ':') {
+		/* option with no argument. Just return it */
+		gs->arg = NULL;
+		gs->arg_index++;
+		return curopt;
+	}
+
+	if (*(curoptp + 1) && *(curoptp + 2) == ':') {
+		/* optional argument */
+		if (argv[gs->index][gs->arg_index + 1]) {
+			/* optional argument with directly following arg */
+			gs->arg = argv[gs->index++] + gs->arg_index + 1;
+			gs->arg_index = 1;
+			return curopt;
+		}
+		if (gs->index + 1 == argc) {
+			/* We are at the last argv[] element */
+			gs->arg = NULL;
+			gs->index++;
+			return curopt;
+		}
+		if (*argv[gs->index + 1] != '-') {
+			/*
+			 * optional argument with arg in next argv[] element
+			 */
+			gs->index++;
+			gs->arg = argv[gs->index++];
+			gs->arg_index = 1;
+			return curopt;
+		}
+
+		/* no optional argument found */
+		gs->arg = NULL;
+		gs->arg_index = 1;
+		gs->index++;
+		return curopt;
+	}
+
+	if (argv[gs->index][gs->arg_index + 1]) {
+		/* required argument with directly following arg */
+		gs->arg = argv[gs->index++] + gs->arg_index + 1;
+		gs->arg_index = 1;
+		return curopt;
+	}
+
+	gs->index++;
+	gs->arg_index = 1;
+
+	if (gs->index >= argc || argv[gs->index][0] == '-') {
+		if (!silent)
+			printf("option requires an argument -- %c\n", curopt);
+		gs->opt = curopt;
+		return ':';
+	}
+
+	gs->arg = argv[gs->index++];
+	return curopt;
+}