From 14e277affd93e4bbf55408fb2b4b8d145377630c Mon Sep 17 00:00:00 2001
From: Bartosz Golaszewski <bartekgola@gmail.com>
Date: Fri, 6 Jan 2017 16:21:09 +0100
Subject: [PATCH] gpioget: use tools-common

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
---
 gpioget.c | 74 ++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 51 insertions(+), 23 deletions(-)

diff --git a/gpioget.c b/gpioget.c
index c32bc87..7f09e7b 100644
--- a/gpioget.c
+++ b/gpioget.c
@@ -9,43 +9,71 @@
  */
 
 #include "gpiod.h"
+#include "tools-common.h"
 
 #include <stdio.h>
 #include <string.h>
+#include <getopt.h>
+
+static const struct option longopts[] = {
+	{ "help",	no_argument,	NULL,	'h' },
+	{ "active-low",	no_argument,	NULL,	'l' },
+	{ 0 },
+};
+
+static const char *const shortopts = "hl";
 
 int main(int argc, char **argv)
 {
+	bool active_low = false;
+	int value, optc, opti;
 	unsigned int offset;
 	char *device, *end;
-	int value;
 
-	if (argc < 2) {
-		fprintf(stderr, "%s: gpiochip must be specified\n", argv[0]);
-		return EXIT_FAILURE;
-	}
+	set_progname(argv[0]);
 
-	if (argc < 3) {
-		fprintf(stderr,
-			"%s: gpio line offset must be specified\n", argv[0]);
-		return EXIT_FAILURE;
+	for (;;) {
+		optc = getopt_long(argc, argv, shortopts, longopts, &opti);
+		if (optc < 0)
+			break;
+
+		switch (optc) {
+		case 'h':
+			printf("Usage: %s [CHIP NAME/NUMBER] [LINE OFFSET] <options>\n",
+			       get_progname());
+			printf("List all GPIO chips\n");
+			printf("Options:\n");
+			printf("  -h, --help:\t\tdisplay this message and exit\n");
+			printf("  -l, --active-low:\tset the line active state to low\n");
+			exit(EXIT_SUCCESS);
+		case 'l':
+			active_low = true;
+			break;
+		case '?':
+			die("try %s --help", get_progname());
+		default:
+			abort();
+		}
 	}
 
-	device = argv[1];
+	argc -= optind;
+	argv += optind;
+
+	if (argc < 1)
+		die("gpiochip must be specified");
+
+	if (argc < 2)
+		die("gpio line offset must be specified");
+
+	device = argv[0];
 	/* FIXME Handle negative numbers. */
-	offset = strtoul(argv[2], &end, 10);
-	if (*end != '\0') {
-		fprintf(stderr,
-			"%s: invalid GPIO offset: %s\n", argv[0], argv[2]);
-		return EXIT_FAILURE;
-	}
+	offset = strtoul(argv[1], &end, 10);
+	if (*end != '\0')
+		die("invalid GPIO offset: %s", argv[1]);
 
-	value = gpiod_simple_get_value(device, offset, false);
-	if (value < 0) {
-		fprintf(stderr,
-			"%s: error reading GPIO value: %s\n",
-			argv[0], strerror(-value));
-		return EXIT_FAILURE;
-	}
+	value = gpiod_simple_get_value(device, offset, active_low);
+	if (value < 0)
+		die_perror("error reading GPIO value");
 
 	printf("%d\n", value);
 
-- 
2.30.2