Rewrite with style (and relicense)8.0

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 425 insertions, 0 deletions

diff --git a/adjbacklight.c b/adjbacklight.c
new file mode 100644
index 0000000..9fe68c1
--- /dev/null
+++ b/adjbacklight.c
@@ -0,0 +1,425 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/ioctl.h>
+#include <sys/wait.h>
+#include <alloca.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "arg.h"
+
+
+#ifndef BACKLIGHT_DIR
+# define BACKLIGHT_DIR "/sys/class/backlight"
+#endif
+
+
+
+char *argv0;
+static double brightness = 0;
+static int nbrightness = 0;
+static int cols = 80;
+static char *space;
+static char *line;
+
+
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage: %s [-g | -s [+|-]level[%%|%%%%]] [-a | device ...]\n", argv0);
+	exit(1);
+}
+
+
+static long int
+readfile(const char *path)
+{
+	int fd;
+	char buf[64];
+	ssize_t i, n;
+	long int value = 0;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	while ((n = read(fd, buf, sizeof(buf))) > 0) {
+		for (i = 0; i < n; i++) {
+			if (isdigit(buf[i]))
+				value = value * 10 + (buf[i] - '0');
+			else if (buf[i] != '\n')
+				goto out;
+		}
+	}
+
+out:
+	close(fd);
+	return n ? -1 : value;
+}
+
+
+static double
+getbrightness(const char *device, long int *out_cur, long int *out_max)
+{
+	size_t n = sizeof("//max_brightness") - 1;
+	char *path;
+	long int max, cur;
+
+	n += strlen(BACKLIGHT_DIR);
+	n += strlen(device);
+	path = alloca(n + 1);
+
+	if (sprintf(path, "%s/%s/max_brightness", BACKLIGHT_DIR, device) != (int)n)
+		abort();
+	max = readfile(path);
+	if (max < 1)
+		return -1;
+	if (out_max)
+		*out_max = max;
+
+	if (sprintf(path, "%s/%s/brightness", BACKLIGHT_DIR, device) != (int)n - 4)
+		abort();
+	cur = readfile(path);
+	if (cur < 0)
+		return -1;
+	if (out_cur)
+		*out_cur = cur;
+
+	return (double)cur / (double)max;
+}
+
+
+static int
+setbrightness(const char *device, long int value)
+{
+	size_t p = 0, n = sizeof("//brightness") - 1;
+	char *path, buf[128];
+	ssize_t r = 0;
+	int fd;
+
+	n += strlen(BACKLIGHT_DIR);
+	n += strlen(device);
+	path = alloca(n + 1);
+
+	if (sprintf(path, "%s/%s/brightness", BACKLIGHT_DIR, device) != (int)n)
+		abort();
+	if (sprintf(buf, "%li\n", value) < 0)
+		abort();
+
+	fd = open(path, O_WRONLY);
+	if (fd < 0)
+		return -1;
+
+	for (n = strlen(buf); p < n; p += (size_t)r)
+		if ((r = write(fd, &buf[p], n - p)) < 0)
+			break;
+
+	close(fd);
+	return r < 0 ? -1 : 0;
+}
+
+
+static int
+adjbrightness(const char *device, double pcur, long int cur, long int max, double adj, int inc, const char *suf)
+{
+	switch (strlen(suf)) {
+	case 2:
+		pcur = adj * pcur / 100 + pcur * inc;
+		cur = (long int)(pcur * (double)max + 0.5);
+		break;
+	case 1:
+		pcur = adj / 100 + pcur * inc;
+		cur = (long int)(pcur * (double)max + 0.5);
+		break;
+	case 0:
+		cur = (long int)adj + cur * inc;
+		break;
+	default:
+		abort();
+	}
+
+	cur = cur < 0 ? 0 : cur < max ? cur : max;
+	return setbrightness(device, cur);
+}
+
+
+static void
+bars(long int max, long int init, long int cur)
+{
+	long int mid = (long int)((double)cur * (double)(cols - 2) / (double)max + 0.5);
+
+	printf("\033[%iD\033[6A", cols);
+	printf("\033[2K┌%s┐\n", line);
+	space[mid] = '\0';
+	printf("\033[2K│\033[47m%s\033[49m%s│\n", space, &space[mid + 1]);
+	space[mid] = ' ';
+	printf("\033[2K└%s┘\n", line);
+	printf("\033[2KMaximum brightness: %li\n", max);
+	printf("\033[2KInitial brightness: %li\n", init);
+	printf("\033[2KCurrent brightness: %li\n", cur);
+
+	fflush(stdout);
+}
+
+
+static void
+interactive(const char *device, long int cur, long int max)
+{
+	long int step, init;
+	int c;
+
+	step = max / 200;
+	step = step ? step : 1;
+	init = cur;
+
+	printf("\n\n\n\n\n\n");
+	bars(max, init, cur);
+	while ((c = getchar()) != -1) {
+		switch (c) {
+		case 'q':
+		case '\n':
+		case 4:
+			printf("\n");
+			return;
+		case 'A':
+		case 'C':
+			cur += step << 1;
+			/* fall through */
+		case 'B':
+		case 'D':
+			cur -= step;
+			cur = cur < 0 ? 0 : cur < max ? cur : max;
+			adjbrightness(device, 0, 0, max, (double)cur, 0, "");
+			bars(max, init, cur);
+		}
+	}
+}
+
+
+static void
+handle_device(const char *device, int get, int set, double adj, int inc, const char *suf)
+{
+	double value;
+	long int cur, max;
+
+	value = getbrightness(device, &cur, &max);
+
+	if (get) {
+		if (value >= 0) {
+			brightness += value;
+			nbrightness++;
+		}
+	} else if (set) {
+		adjbrightness(device, value, cur, max, adj, inc, suf);
+	} else {
+		interactive(device, cur, max);
+	}
+}
+
+
+int
+main(int argc, char *argv[])
+{
+	int all = 0;
+	int get = 0;
+	char* set = NULL;
+	char set_prefix = '=';
+	double set_value = 0;
+	char* set_suffix = NULL;
+	struct winsize win;
+	struct termios saved_stty;
+	struct termios stty;
+	pid_t pid = -1;
+	DIR *dir;
+	struct dirent *ent;
+	int any = 0;
+
+	ARGBEGIN {
+	case 'a':
+		all = 1;
+		break;
+	case 'g':
+		get = 1;
+		break;
+	case 's':
+		set = EARGF(usage());
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if ((get && set) || (argc && all))
+		usage();
+
+	/* Parse -s argument */
+	if (set) {
+		if (*set == '+' || *set == '-') {
+			set_prefix = *set;
+			set++;
+		}
+		if (!isdigit(*set) && *set != '.')
+			usage();
+		errno = 0;
+		set_value = strtod(set, &set_suffix);
+		if (errno || set_value < 0) {
+			fprintf(stderr, "%s: strtod %s: %s\n", argv0, set, strerror(errno));
+			return 1;
+		}
+		if (*set_suffix && strcmp(set_suffix, "%") && strcmp(set_suffix, "%%"))
+			usage();
+		if (set_prefix == '-') {
+			set_value = -set_value;
+			set_prefix = '+';
+		}
+	}
+
+	/* Check permissions (important because the program is installed with set-uid) */
+	if (getuid()) {
+		struct group *videogrp = getgrnam("video");
+		if (!videogrp && errno && errno != ENOENT && errno != ESRCH && errno != EPERM) {
+			/* Note, glibc sets errno to EIO if the group does not exist,
+			 * this is the not the specified behavour by either POSIX or
+			 * glibc, and it would be a security issue to treat it as OK.
+			 * Additionally, EBADF is not treated as OK. */
+			fprintf(stderr, "%s: getgrnam video: %s\n", argv0, strerror(errno));
+			return 1;
+		} else if (videogrp) {
+			long ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
+			gid_t *groups;
+			int ngroups;
+			if (ngroups_max < 0 || ngroups_max > INT_MAX - 1) {
+				fprintf(stderr, "%s: sysconf _SC_NGROUPS_MAX: %s\n", argv0, strerror(errno));
+				return 1;
+			}
+			groups = alloca((size_t)ngroups_max * sizeof(*groups));
+			ngroups = getgroups((int)ngroups_max, groups);
+			if (ngroups < 0) {
+				fprintf(stderr, "%s: getgroups: %s\n", argv0, strerror(errno));
+				return 1;
+			}
+			while (ngroups--)
+				if (groups[ngroups] == videogrp->gr_gid)
+					break;
+			if (ngroups < 0) {
+				fprintf(stderr, "%s: only root and members of the group 'video' may run this command\n", argv0);
+				return 1;
+			}
+		}
+	}
+
+	if (!get && !set) {
+		int i;
+		printf("\n\n");
+		printf("If the program is abnormally aborted the may be some residual\n");
+		printf("effects on the terminal. the following commands should reset it:\n");
+		printf("\n");
+		printf("    stty sane\n");
+		printf("    printf '\\ec'\n");
+		printf("\n");
+		printf("\n\n\n\n");
+
+		/* Get the size of the terminal */
+		if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == -1)
+			fprintf(stderr, "%s: ioctl <stdout> TIOCGWINSZ: %s\n", argv0, strerror(errno));
+		else
+			cols = win.ws_col;
+
+		line = malloc((size_t)cols * 3);
+		space = malloc((size_t)cols);
+		if (!line || !space) {
+			fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(ENOMEM));
+			return 1;
+		}
+		for (i = 0; i < cols; i++) {
+			line[i * 3 + 0] = (char)(0xE2);
+			line[i * 3 + 1] = (char)(0x94);
+			line[i * 3 + 2] = (char)(0x80);
+		}
+		memset(space, ' ', (size_t)cols);
+		space[cols - 1] = '\0';
+		line[(cols - 2) * 3] = '\0';
+
+		/* stty -icanon -echo */
+		if (tcgetattr(STDIN_FILENO, &stty)) {
+			fprintf(stderr, "%s: tcgetattr <stdin>: %s\n", argv0, strerror(errno));
+			return 1;
+		}
+		saved_stty = stty;
+		stty.c_lflag &= (tcflag_t)~(ICANON | ECHO);
+		if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty)) {
+			fprintf(stderr, "%s: tcsetattr <stdin>: %s\n", argv0, strerror(errno));
+			return 1;
+		}
+
+		/* Hide cursor */
+		printf("%s", "\033[?25l");
+		fflush(stdout);
+
+		/* Fork to diminish risk of unclean exit */
+		pid = fork();
+		if (pid == (pid_t)-1) {
+			fprintf(stderr, "%s: fork: %s\n", argv0, strerror(errno));
+		} else if (pid) {
+			waitpid(pid, NULL, 0);
+			goto done;
+		}
+	}
+
+	if (argc) {
+		for (; *argv; argv++) {
+			if (strchr(*argv, '/'))
+				*argv = strrchr(*argv, '/');
+			handle_device(*argv, get, !!set, set_value, set_prefix == '+', set_suffix);
+		}
+	} else {
+		if ((dir = opendir(BACKLIGHT_DIR))) {
+			while ((ent = readdir(dir))) {
+				if (all || strstr(ent->d_name, "acpi_video") == ent->d_name) {
+					if (*ent->d_name && *ent->d_name != '.') {
+						handle_device(ent->d_name, get, !!set, set_value, set_prefix == '+', set_suffix);
+						any = 1;
+					}
+				}
+			}
+			closedir(dir);
+		}
+		if (!any)
+			fprintf(stderr, "%s: cannot find any backlight devices\n", argv0);
+	}
+
+	if (get) {
+		if (nbrightness) {
+			brightness *= 100;
+			brightness /= (double)nbrightness;
+			printf("%.2lf%%\n", brightness);
+			fflush(stdout);
+		} else {
+			printf("%s\n", "100.00%");
+			fflush(stdout);
+		}
+	}
+
+done:
+      if (!get && !set && pid) {
+	      /* Show cursor */
+	      printf("%s", "\033[?25h");
+	      fflush(stdout);
+
+	      /* `stty icanon echo` */
+	      if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty)) {
+		      fprintf(stderr, "%s: tcsetattr <stdin>: %s\n", argv0, strerror(errno));
+		      return 1;
+	      }
+      }
+
+      return 0;
+}