summaryrefslogtreecommitdiffstats
path: root/backlight.c
diff options
context:
space:
mode:
Diffstat (limited to 'backlight.c')
-rw-r--r--backlight.c507
1 files changed, 507 insertions, 0 deletions
diff --git a/backlight.c b/backlight.c
new file mode 100644
index 0000000..633f04c
--- /dev/null
+++ b/backlight.c
@@ -0,0 +1,507 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[name] ...");
+
+
+static volatile sig_atomic_t caught_sigterm = 0;
+static volatile sig_atomic_t caught_sigwinch = 1;
+static volatile sig_atomic_t caught_sigio = 0;
+
+static int info = 0;
+static char path[4096];
+
+
+
+static void
+sigterm(int signo)
+{
+ caught_sigterm = 1;
+ (void) signo;
+}
+
+static void
+sigwinch(int signo)
+{
+ caught_sigwinch = 1;
+ (void) signo;
+}
+
+static void
+sigio(int signo)
+{
+ caught_sigio = 1;
+ (void) signo;
+}
+
+
+static void
+writefile(const char *path, char *buf, size_t size)
+{
+ int fd;
+ size_t off = 0;
+ ssize_t r;
+
+ fd = open(path, O_WRONLY);
+ if (fd < 0) {
+ weprintf("write %s:", path);
+ return;
+ }
+
+ for (;;) {
+ r = write(fd, &buf[off], size - off);
+ if (r <= 0) {
+ if (!r)
+ break;
+ close(fd);
+ weprintf("write %s:", path);
+ return;
+ }
+ off += (size_t)r;
+ }
+
+ close(fd);
+}
+
+
+static int
+readstrfile(const char *path, char *buf, size_t size)
+{
+ int fd;
+ size_t off = 0, i, j;
+ ssize_t r;
+ char c;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return 0;
+
+ for (;;) {
+ r = read(fd, &buf[off], size - sizeof("…") - off);
+ if (r <= 0) {
+ if (!r)
+ break;
+ close(fd);
+ return 0;
+ }
+ off += (size_t)r;
+ }
+
+ off -= (off && buf[off - 1] == '\n');
+
+ if (off == size - sizeof("…")) {
+ for (i = 0; i < off;) {
+ if ((buf[i] & 0xC0) == 0xC0) {
+ j = i;
+ c = buf[i];
+ do {
+ c <<= 1;
+ i++;
+ } while ((c & 0x80) && i < off && (buf[i] & 0xC0) == 0x80);
+ if (c & 0x80) {
+ off = j;
+ break;
+ }
+ } else {
+ i += 1;
+ }
+ }
+ memcpy(&buf[off], "…", sizeof("…"));
+ } else {
+ buf[off] = '\0';
+ }
+
+ close(fd);
+ return 1;
+}
+
+static int
+readintfile(const char *path, uintmax_t *valuep)
+{
+ char buf[256], *end;
+ int r;
+ r = readstrfile(path, buf, sizeof(buf));
+ if (r <= 0)
+ return r;
+ if (!isdigit(*buf))
+ return 0;
+ errno = 0;
+ *valuep = strtoumax(buf, &end, 10);
+ if (errno || *end)
+ return 0;
+ return 1;
+}
+
+
+static void
+adjust_fine(const char *path, uintmax_t max_brightness, uintmax_t *brightnessp, uintmax_t adjustment)
+{
+ char buf[sizeof(uintmax_t) * 3 + 2];
+ uintmax_t brightness = *brightnessp, result;
+ int len;
+
+fprintf(stderr, "START\n");
+again:
+fprintf(stderr, "adjusting: %ju, %ju, %ju, %ju\n", brightness, *brightnessp, max_brightness, adjustment);
+
+ if (max_brightness) {
+ if (adjustment >= max_brightness - brightness)
+ brightness = max_brightness;
+ else
+ brightness += adjustment;
+ } else {
+ if (brightness < adjustment)
+ brightness = 0;
+ else
+ brightness -= adjustment;
+ }
+
+fprintf(stderr, "setting: %ju, %s\n", brightness, path);
+ len = sprintf(buf, "%ju\n", brightness);
+ writefile(path, buf, (size_t)len);
+
+ if (readintfile(path, &result)) {
+fprintf(stderr, "result: %ju, %ju, %ju, %ju\n", result, brightness, *brightnessp, max_brightness);
+ if (result == *brightnessp && brightness != max_brightness)
+ goto again;
+ *brightnessp = result;
+ }
+fprintf(stderr, "END: %ju\n", *brightnessp);
+}
+
+
+static int
+show_backlights(int tfd, char **devs, size_t ndevs)
+{
+ struct winsize winsize;
+ char buf[256], c, prev_c = 0, *p, *colour, line[(sizeof("─") - 1) * 64 + 1];
+ int width = 0, height = 0, left = 0, namelen = 0, first = 1, len, digits;
+ int rearm = 1, redraw = 0, reload = 1, i;
+ int have_max = 0, have_current = 0, vis_brightness_at;
+ uintmax_t max_brightness = 0, brightness = 0;
+ double percent;
+ size_t index = 0, k;
+ ssize_t r;
+
+ for (k = 0, p = line; k < 64; k++)
+ p = stpcpy(p, "—");
+
+ while (!caught_sigterm) {
+ if (caught_sigwinch) {
+ if (ioctl(STDOUT_FILENO, (unsigned long)TIOCGWINSZ, &winsize) < 0) {
+ if (errno == EINTR)
+ continue;
+ weprintf("ioctl <stdout> TIOCGWINSZ:");
+ return -1;
+ }
+ caught_sigwinch = 0;
+ width = winsize.ws_col;
+ height = winsize.ws_row;
+ if (height > 2)
+ height -= 2;
+ else
+ height = 0;
+ if (width > 10) {
+ width /= 5;
+ if (width < 10)
+ width = 10;
+ }
+ left = (winsize.ws_col - width) / 2;
+ redraw = 1;
+ }
+ if (first) {
+ first = 0;
+ } else if (caught_sigio) {
+ caught_sigio = 0;
+ for (;;) {
+ r = read(STDIN_FILENO, &c, 1);
+ if (r <= 0) {
+ if (!r)
+ return 0;
+ if (errno == EAGAIN)
+ break;
+ if (errno == EINTR)
+ continue;
+ weprintf("read <stdin>:");
+ return -1;
+ }
+ if (c == 'r') {
+ rearm = 1;
+ } else if (c == 'L' - '@') {
+ redraw = 1;
+ } else if (c == 'i') {
+ info ^= 1;
+ redraw = 1;
+ stpcpy(p, "/brightness");
+ } else if (c == 'q') {
+ return 0;
+ } else if (c == 'C') {
+ if (ndevs > 1) {
+ redraw = 1;
+ index = (index + 1) % ndevs;
+ reload = 1;
+ have_current = 0;
+ }
+ } else if (c == 'D') {
+ if (ndevs > 1) {
+ redraw = 1;
+ if (!index)
+ index = ndevs;
+ index -= 1;
+ reload = 1;
+ have_current = 0;
+ }
+ } else if (c == 'A' && have_max) {
+ if (!have_current) {
+ stpcpy(p, "/brightness");
+ have_current = readintfile(path, &brightness);
+ }
+ if (have_current && brightness < max_brightness) {
+ redraw = 1;
+ adjust_fine(path, max_brightness, &brightness, 1);
+ }
+ } else if (c == 'B' && have_max) {
+ if (!have_current) {
+ stpcpy(p, "/brightness");
+ have_current = readintfile(path, &brightness);
+ }
+ if (have_current && brightness) {
+ redraw = 1;
+ adjust_fine(path, 0, &brightness, 1);
+ }
+ } else if (c == '~' && prev_c == '5' && have_max) {
+ if (!have_current) {
+ stpcpy(p, "/brightness");
+ have_current = readintfile(path, &brightness);
+ }
+ if (have_current && brightness < max_brightness) {
+ redraw = 1;
+ adjust_fine(path, max_brightness, &brightness, max_brightness / 10);
+ }
+ } else if (c == '~' && prev_c == '6' && have_max) {
+ if (!have_current) {
+ stpcpy(p, "/brightness");
+ have_current = readintfile(path, &brightness);
+ }
+ if (have_current && brightness) {
+ redraw = 1;
+ adjust_fine(path, 0, &brightness, max_brightness / 10);
+ }
+ }
+ prev_c = c;
+ }
+ }
+
+ /* Need instead of a sleep at the and to remove artifacts when there is a lot of input */
+ if (rearm) {
+ if (timerfd_settime(tfd, 0, &(struct itimerspec){{0, 100000000L}, {0, 100000000L}}, NULL)) {
+ weprintf("timerfd_settime <timerfd> 0 {0.1s 0.1s} NULL:");
+ return -1;
+ }
+ rearm = 0;
+ redraw = 0;
+ } else if (redraw) {
+ redraw = 0;
+ } else {
+ if (read(tfd, &(int64_t){0}, sizeof(int64_t)) < 0) {
+ if (errno == EINTR)
+ continue;
+ weprintf("read <timerfd> &(int64_t) sizeof(int64_t):");
+ return -1;
+ }
+ }
+
+ if (reload) {
+ reload = 0;
+ namelen = strlen(devs[index]);
+ p = stpcpy(stpcpy(path, "/sys/class/backlight/"), devs[index]);
+ stpcpy(p, "/max_brightness");
+ have_max = readintfile(path, &max_brightness);
+ stpcpy(p, "/brightness");
+ }
+
+ if (info) {
+ printf("\033[H\033[1m%s\033[m\033[K\n\033[K", devs[index]);
+ stpcpy(p, "/max_brightness");
+ if (readstrfile(path, buf, sizeof(buf)))
+ printf("\n\033[1mMaximum brightness:\033[m %s\033[K", buf);
+ stpcpy(p, "/brightness");
+ if (readstrfile(path, buf, sizeof(buf)))
+ printf("\n\033[1mBrightness:\033[m %s\033[K", buf);
+ stpcpy(p, "/actual_brightness");
+ if (readstrfile(path, buf, sizeof(buf)))
+ printf("\n\033[1mActual brightness:\033[m %s\033[K", buf);
+ stpcpy(p, "/bl_power");
+ if (readstrfile(path, buf, sizeof(buf)))
+ printf("\n\033[1mBacklight power:\033[m %s\033[K", buf);
+ stpcpy(p, "/scale");
+ if (readstrfile(path, buf, sizeof(buf)))
+ printf("\n\033[1mScale:\033[m %s\033[K", buf);
+ stpcpy(p, "/type");
+ if (readstrfile(path, buf, sizeof(buf)))
+ printf("\n\033[1mType:\033[m %s\033[K", buf);
+ printf("\033[J");
+ fflush(stdout);
+ continue;
+ }
+
+ have_current = readintfile(path, &brightness);
+
+ printf("\033[H%*.s\033[1m%s\033[m\033[K\n", (winsize.ws_col - namelen) / 2, "", devs[index]);
+ if (!have_max || !max_brightness) {
+ len = (int)(sizeof("Maximum brightness is unavailable") - 1);
+ printf("%*.s%s\033[K\n", (winsize.ws_col - len) / 2, "", "Maximum brightness is unavailable");
+ } else if (!have_current) {
+ len = (int)(sizeof("Current brightness is unavailable") - 1);
+ printf("%*.s%s\033[K\n", (winsize.ws_col - len) / 2, "", "Current brightness is unavailable");
+ } else {
+ if (width > 2 && height > 12) {
+ printf("%*.s┌", left, "");
+ for (i = 2; i + 64 < width; i += 64)
+ printf("%s", line);
+ if (i < width)
+ printf("%.*s", (width - i) * ((int)sizeof("─") - 1), line);
+ printf("┐\033[K\n");
+
+ vis_brightness_at = (int)((brightness * (uintmax_t)(height - 2) * 2 + 1) / (max_brightness * 2));
+ vis_brightness_at = 1 + height - 2 - vis_brightness_at;
+ for (i = 2; i < height; i++) {
+ colour = (i >= vis_brightness_at) ? "7" : "";
+ printf("%*.s│\033[%sm%*.s\033[m│\033[K\n", left, "", colour, width - 2, "");
+ }
+
+ printf("%*.s└", left, "");
+ for (i = 2; i + 64 < width; i += 64)
+ printf("%s", line);
+ if (i < width)
+ printf("%.*s", (width - i) * ((int)sizeof("─") - 1), line);
+ printf("┘\033[K\n");
+ }
+ digits = max_brightness >= 10000 ? 2 : max_brightness >= 1000 ? 1 : 0;
+ percent = 100. * (double)brightness / (double)max_brightness;
+ len = snprintf(NULL, 0, "%.*lf%% (%ju of %ju)", digits, percent, brightness, max_brightness);
+ printf("%*.s%.*lf%% (%ju of %ju)\033[K", (winsize.ws_col - len) / 2, "",
+ digits, percent, brightness, max_brightness);
+ }
+
+ printf("\033[J");
+ fflush(stdout);
+ }
+
+ return 0;
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ int old_sig = 0, old_flags = -1, tcset = 0, ret, tfd;
+ struct f_owner_ex old_owner, new_owner;
+ struct termios stty, saved_stty;
+ struct sigaction sigact;
+ char **devs = NULL, *p;
+ size_t ndevs = 0;
+ struct dirent *f;
+ DIR *dir;
+
+ ARGBEGIN {
+ case 'i':
+ info = 1;
+ break;
+ default:
+ usage();
+ } ARGEND;
+
+ if (!argc) {
+ dir = opendir("/sys/class/backlight");
+ if (!dir)
+ eprintf("opendir /sys/class/backlight:");
+ while ((errno = 0, f = readdir(dir))) {
+ if (f->d_name[0] == '.')
+ continue;
+ if (strlen(f->d_name) + 256 > sizeof(path))
+ continue;
+ p = stpcpy(stpcpy(path, "/sys/class/backlight/"), f->d_name);
+ stpcpy(p, "/max_brightness");
+ if (access(path, F_OK))
+ continue;
+ stpcpy(p, "/brightness");
+ if (access(path, F_OK))
+ continue;
+ devs = erealloc2(devs, ndevs + 1, sizeof(*devs));
+ devs[ndevs] = strdup(f->d_name);
+ if (!devs[ndevs++])
+ eprintf("strdup:");
+ }
+ closedir(dir);
+ if (errno)
+ eprintf("readdir /sys/class/backlight:");
+ if (!ndevs)
+ eprintf("no backlight devices found\n");
+ } else {
+ devs = argv;
+ ndevs = (size_t)argc;
+ }
+
+ memset(&sigact, 0, sizeof(sigact));
+
+ sigact.sa_handler = sigterm;
+ sigaction(SIGTERM, &sigact, NULL);
+ sigaction(SIGQUIT, &sigact, NULL);
+ sigaction(SIGINT, &sigact, NULL);
+
+ sigact.sa_handler = sigwinch;
+ sigaction(SIGWINCH, &sigact, NULL);
+
+ sigact.sa_handler = sigio;
+ sigaction(SIGIO, &sigact, NULL);
+ sigaction(SIGURG, &sigact, NULL);
+
+ tfd = timerfd_create(CLOCK_MONOTONIC, 0);
+ if (tfd < 0)
+ eprintf("timerfd_create CLOCK_MONOTONIC 0:");
+
+ if (fcntl(STDIN_FILENO, F_GETOWN_EX, &old_owner))
+ eprintf("fcntl <stdin> F_GETOWN_EX:");
+ memset(&new_owner, 0, sizeof(new_owner));
+ new_owner.type = F_OWNER_PID;
+ new_owner.pid = getpid();
+ if (fcntl(STDIN_FILENO, F_SETOWN_EX, &new_owner))
+ eprintf("fcntl <stdin> F_SETOWN_EX {.type=F_OWNER_PID, .pid=<getpid()>}:");
+ old_flags = fcntl(STDIN_FILENO, F_GETFL);
+ if (old_flags != -1)
+ fcntl(STDIN_FILENO, F_SETFL, old_flags | FASYNC | O_NONBLOCK);
+ fcntl(STDIN_FILENO, F_GETSIG, &old_sig);
+ if (old_sig)
+ fcntl(STDIN_FILENO, F_SETSIG, 0);
+
+ if (!tcgetattr(STDIN_FILENO, &stty)) {
+ saved_stty = stty;
+ stty.c_lflag &= (tcflag_t)~(ECHO | ICANON);
+ tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty);
+ tcset = 1;
+ }
+
+ fprintf(stdout, "\033[?1049h\033[?25l");
+
+ ret = -show_backlights(tfd, devs, ndevs);
+
+ fprintf(stdout, "\033[?25h\n\033[?1049l");
+ fflush(stdout);
+
+ fcntl(STDIN_FILENO, F_SETOWN_EX, &old_owner);
+ if (old_flags != -1)
+ fcntl(STDIN_FILENO, F_SETFL, old_flags);
+ if (old_sig)
+ fcntl(STDIN_FILENO, F_SETSIG, old_sig);
+ if (tcset)
+ tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty);
+ close(tfd);
+ if (!argc) {
+ while (ndevs--)
+ free(devs[ndevs]);
+ free(devs);
+ }
+
+ return ret;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.51.0) at 2026-02-20 23:52:29 +0000