From 2b61befef595ce5a7f0a94f8bcadd1a2731ffe13 Mon Sep 17 00:00:00 2001
From: Mykyta Holubakha <hilobakho@gmail.com>
Date: Mon, 6 Sep 2021 10:26:23 +0300
Subject: [PATCH] Support displaying brightness as a percentage

Closes #56
Resolves #55
---
 brightnessctl.1 |  6 ++++++
 brightnessctl.c | 15 +++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/brightnessctl.1 b/brightnessctl.1
index 83faf8d..5b490c3 100644
--- a/brightnessctl.1
+++ b/brightnessctl.1
@@ -42,6 +42,12 @@ Do not perform write operations.
 Produce machine\-readable output.
 .RE
 
+.sp
+\fB\-P, \-\-percentage\fP
+.RS 4
+Display value as a percentage in get.
+.RE
+
 .sp
 \fB\-n, \-\-min\-value\fP=\fIVALUE\fP
 .RS 4
diff --git a/brightnessctl.c b/brightnessctl.c
index 6045ec3..d8ec1b3 100644
--- a/brightnessctl.c
+++ b/brightnessctl.c
@@ -44,6 +44,8 @@ static int read_class(struct device **, char *);
 static int read_devices(struct device **);
 static void print_device(struct device *);
 static void list_devices(struct device **);
+static float val_to_percent(float, struct device *, bool);
+static unsigned long percent_to_val(float, struct device *);
 static struct device *find_device(struct device **, char *);
 static bool save_device_data(struct device *);
 static bool restore_device_data(struct device *);
@@ -85,6 +87,7 @@ struct params {
 	bool list;
 	bool pretend;
 	bool mach;
+	bool percentage;
 	bool save;
 	bool restore;
 	float exponent;
@@ -98,6 +101,7 @@ static const struct option options[] = {
 	{"help", no_argument, NULL, 'h'},
 	{"list", no_argument, NULL, 'l'},
 	{"machine-readable", no_argument, NULL, 'm'},
+	{"percentage", no_argument, NULL, 'P'},
 	{"min-value", optional_argument, NULL, 'n'},
 	{"exponent", optional_argument, NULL, 'e'},
 	{"quiet", no_argument, NULL, 'q'},
@@ -122,7 +126,7 @@ int main(int argc, char **argv) {
 		fail("This program only supports Linux.\n");
 	p.exponent = 1;
 	while (1) {
-		if ((c = getopt_long(argc, argv, "lqpmn::e::srhVc:d:", options, NULL)) < 0)
+		if ((c = getopt_long(argc, argv, "lqpmPn::e::srhVc:d:", options, NULL)) < 0)
 			break;
 		switch (c) {
 		case 'l':
@@ -143,6 +147,9 @@ int main(int argc, char **argv) {
 		case 'm':
 			p.mach = true;
 			break;
+		case 'P':
+			p.percentage = true;
+			break;
 		case 'n':
 			if (optarg)
 				p.min = atol(optarg);
@@ -246,7 +253,10 @@ int apply_operation(struct device *dev, enum operation operation, struct value *
 		print_device(dev);
 		return 0;
 	case GET:
-		fprintf(stdout, "%u\n", dev->curr_brightness);
+		if (p.percentage)
+			fprintf(stdout, "%d\n", (int) val_to_percent(dev->curr_brightness, dev, true));
+		else
+			fprintf(stdout, "%u\n", dev->curr_brightness);
 		return 0;
 	case MAX:
 		fprintf(stdout, "%u\n", dev->max_brightness);
@@ -643,6 +653,7 @@ Options:\n\
   -q, --quiet\t\t\tsuppress output.\n\
   -p, --pretend\t\t\tdo not perform write operations.\n\
   -m, --machine-readable\tproduce machine-readable output.\n\
+  -P, --percentage\t\tdisplay value as a percentage in get.\n\
   -n, --min-value\t\tset minimum brightness, defaults to 1.\n\
   -e, --exponent[=K]\t\tchanges percentage curve to exponential.\n\
   -s, --save\t\t\tsave previous state in a temporary file.\n\
-- 
2.43.2