/**
* adjbacklight – Convient method for adjusting the backlight on your portable computer
*
* Copyright © 2012, 2013, 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <unistd.h>
#include <dirent.h>
#include <string.h>
#include <limits.h>
#include <alloca.h>
#include <grp.h>
#include <pwd.h>
#ifndef PATH_MAX
#warning PATH_MAX is not defined
#define PATH_MAX 4096
#endif
/**
* The years this software has been developed
*/
#define _YEARS_ "2012, 2013, 2014"
/**
* Forking method
*/
#ifndef FORK
#define FORK fork
#endif
/**
* The directory where the backlight devices are found and configured
*/
#ifndef BACKLIGHT_DIR
#define BACKLIGHT_DIR "/sys/class/backlight"
#endif
/**
* Print a line to stdout
*
* @param S:const char* The string to print
*/
#define P(S) printf("%s", S "\n")
/**
* Cut a string of at the first line break
* A help `int` named `i` must be available
*
* @param data:char* The string, it will be modified
* @return :char* The input string, it has been modified
*/
#define unnl(data) \
({ \
for (i = 0; *(data + i); i++) \
if (*(data + i) == '\n') \
*(data + i) = 0; \
data; \
})
/**
* Test whether a string numerical and with at most two trailing '%'
*
* @param str The string
* @return Whether the test passed
*/
static int isnumerical(const char* str);
/**
* Interactively adjust the backlight on a device
*
* @param cols The number of columns on the terminal
* @param device The device on which to adjust backlight
*/
static void adjust(int cols, const char* device);
/**
* Gets the current backlight setting on a device
*
* @param device The device from which to get backlight
* @return The brightness as a [0; 1] float, negative on error
*/
static float getbrightness(const char* device);
/**
* Sets the current backlight setting on a device
*
* @param device The device from which to get backlight
* @param adjustment The adjustment to make
*/
static void setbrightness(const char* device, const char* adjustment);
/**
* Read a file
*
* @param output Buffer to store the file's content in
* @param file The file to read
* @return Zero on success, non-zero on failure
*/
static int readfile(char* output, const char* file);
/**
* Write an integer to a file
*
* @param buffer Buffer for temporary data
* @param integer The integer to write
* @param file The file to which to write
* @return Zero on success, non-zero on failure
*/
static int writefile(char* buffer, int integer, const char* file);
/**
* Print the status
*
* @param min The minimum possible brightness
* @param max The maximum possible brightness
* @param init The brightness used when the program started
* @param cur The current brightness
* @param cols The number of columns on the terminal
*/
static void bars(int min, int max, int init, int cur, int cols);
/**
* A series of spaces used to print the bar
*/
static char* space;
/**
* A series of vertical lines used to print the bar
*/
static char* line;
/**
* This is the mane entry point of the program
*
* @param argc The number of elements in `argv`
* @parma argv Command line arguments, including the command
* @return Exit value, zero on success
*/
int main(int argc, char** argv)
{
struct winsize win;
struct termios saved_stty;
struct termios stty;
int i, j;
pid_t pid = 0;
char* set = NULL;
int get = 0, help = 0, all = 0, cols = 80, ndevices = 0;
char** devices = alloca(argc * sizeof(char*));
if (argc > 1)
{
char* arg;
for (i = 1; i < argc; i++)
{
#define T(S) (!strcmp(arg, S))
arg = *(argv + i);
if (T("-h") || T("--help"))
help = 1;
else if (T("-a") || T("--all"))
all = 1;
else if (T("-c") || T("--copyright") || T("--copying"))
{
P("\n");
P("adjbacklight – Convient method for adjusting the backlight on your portable computer");
P("");
P("Copyright © " _YEARS_ " Mattias Andrée (maandree@member.fsf.org)");
P("");
P("This program is free software: you can redistribute it and/or modify");
P("it under the terms of the GNU General Public License as published by");
P("the Free Software Foundation, either version 3 of the License, or");
P("(at your option) any later version.");
P("");
P("This program is distributed in the hope that it will be useful,");
P("but WITHOUT ANY WARRANTY; without even the implied warranty of");
P("MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the");
P("GNU General Public License for more details.");
P("");
P("You should have received a copy of the GNU General Public License");
P("along with this program. If not, see <http://www.gnu.org/licenses/>.");
P("\n");
return 0;
}
else if (T("-w") || T("--warranty"))
{
P("\n");
P("This program is distributed in the hope that it will be useful,");
P("but WITHOUT ANY WARRANTY; without even the implied warranty of");
P("MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the");
P("GNU General Public License for more details.");
P("\n");
return 0;
}
else if (T("-s") || T("--set"))
{
char* tmp;
if (i + 1 == argc)
fprintf(stderr, "%s: argument for option %s is missing, ignoring option\n", *argv, arg);
else
if (!isnumerical(tmp = *(argv + ++i)))
fprintf(stderr, "%s: argument for option %s is malformated, ignoring option\n", *argv, arg);
else
{
set = tmp;
get = 0;
}
}
else if (T("-g") || T("--get"))
{
get = 1;
set = NULL;
}
else if (((*arg == '-') || (*arg == '+') || (*arg == '=')) && isnumerical(arg + 1))
{
set = arg;
get = 0;
}
else
{
if (*arg && (*arg != '-'))
*(devices + ndevices++) = arg;
else
fprintf(stderr, "%s: ignoring unrecognised argument: %s\n", *argv, arg);
}
#undef T
}
fflush(stderr);
if (help || ((all + ndevices + get == 0) && !set))
{
P("\n");
P("adjbacklight - Convient method for adjusting the backlight on your portable computer");
P("");
P("USAGE: adjbacklight (-c | -w | [-g | -s LEVEL | LEVEL] [-a | DEVICE...])");
P("");
P("Run with options to adjust the backlight on your monitors.");
P("");
P("");
P("OPTIONS:");
P("");
P("-c");
P("--copyright");
P("--copying Display copyright information");
P("");
P("-w");
P("--warranty Display warranty disclaimer");
P("");
P("-a");
P("--all Run for all devices, including ACPI devices");
P("");
P("-g");
P("--get Get average brightness on devices");
P("");
P("-s");
P("--set LEVEL[%] Set brightness on devices");
P("");
P("+LEVEL Increase brightness on devices by actual value");
P("-LEVEL Decrease brightness on devices by actual value");
P("=LEVEL Set brightness on devices by actual value");
P("");
P("+LEVEL% Increase brightness on devices by percentage");
P("-LEVEL% Decrease brightness on devices by percentage");
P("=LEVEL% Set brightness on devices by percentage");
P("");
P("+LEVEL%% Increase brightness on devices by relative percentage");
P("-LEVEL%% Decrease brightness on devices by relative percentage");
P("=LEVEL%% Set brightness on devices by relative percentage");
P("");
P("");
P("KEYBOARD:");
P("");
P("←");
P("↓ Darken the screen");
P("");
P("→");
P("↑ Brighten the screen");
P("");
P("q");
P("enter");
P("C-d Continue to next controller, or if at last, quit");
P("");
P("");
P("");
P("Copyright © " _YEARS_ " Mattias Andrée (maandree@member.fsf.org)");
P("");
P("This program is free software: you can redistribute it and/or modify");
P("it under the terms of the GNU General Public License as published by");
P("the Free Software Foundation, either version 3 of the License, or");
P("(at your option) any later version.");
P("");
return 0;
}
}
/* Check permissions */
if (getuid()) /* Always accept root */
{
struct group* video_grp = getgrnam("video");
if (video_grp) /* Accept everypony if the group ‘video’ does not exist */
{
struct passwd* realuser = getpwuid(getuid());
if (!realuser)
{
P("You do not exist, go away!");
return 1;
}
char** mems = video_grp->gr_mem;
char* realname = realuser->pw_name;
int ok = 0;
for (; *mems; mems++)
if (!strcmp(realname, *mems))
{
ok = 1;
break;
}
endgrent();
if (!ok)
{
P("Sorry, you need to be in the group 'video'.");
return 1;
}
}
endpwent();
}
if (!get && !set)
{
P("\n");
P("If the program is abnormally aborted the may be some residual");
P("effects on the terminal. the following commands should reset it:");
P("");
P(" stty icanon echo");
P(" echo -en '\\e[?25h'");
P("");
P("\n\n\n");
}
if (!get && !set)
{
/* Get the size of the terminal */
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == -1)
perror(*argv);
else
cols = win.ws_col;
/* Hide cursor */
printf("%s", "\033[?25l");
fflush(stdout);
/* stty -icanon -echo */
if (tcgetattr(STDIN_FILENO, &stty))
{
perror(*argv);
return 1;
}
saved_stty = stty;
stty.c_lflag &= ~(ICANON | ECHO);
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty))
{
perror(*argv);
return 1;
}
}
/* Fork to diminish risk of unclean exit */
if (!get && !set)
{
pid = FORK();
if (pid == (pid_t)-1)
{
perror(*argv);
pid = 0;
}
}
if (pid)
waitpid(pid, NULL, 0);
else
{
float brightness = 0;
int nbrightness = 0;
if (!get && !set)
{
line = malloc(cols * 3 * sizeof(char));
space = malloc(cols * sizeof(char));
for (i = 0; i < cols; i++)
{
*(line + i * 3 + 0) = (char)(0xE2);
*(line + i * 3 + 1) = (char)(0x94);
*(line + i * 3 + 2) = (char)(0x80);
*(space + i) = ' ';
}
*(space + cols - 1) = 0;
*(line + (cols - 2) * 3) = 0;
}
if (ndevices)
{
char* device;
for (i = 0; i < ndevices; i++)
{
device = *(devices + i);
for (j = 0; *(device + j); j++)
if (*(device + j) == '/')
{
device += j + 1;
j = -1;
}
if (get)
{
float value = getbrightness(device);
if (value >= 0.f)
{
brightness += value;
nbrightness++;
}
}
else if (set)
setbrightness(device, set);
else
adjust(cols, device);
}
}
else
{
struct dirent* ent;
DIR* dir = opendir(BACKLIGHT_DIR);
if (dir)
{
char* device;
char* forbidden = "acpi_video";
while ((ent = readdir(dir)))
{
device = ent->d_name;
if (all || (strstr(device, forbidden) != device))
if (*device && (*device != '.'))
{
if (get)
{
float value = getbrightness(device);
if (value >= 0.f)
{
brightness += value;
nbrightness++;
}
}
else if (set)
setbrightness(device, set);
else
adjust(cols, device);
}
}
closedir(dir);
}
}
if (!get && !set)
{
free(line);
free(space);
}
else if (get)
{
if (nbrightness)
{
brightness *= 100.f;
brightness /= nbrightness;
printf("%.2f%%\n", brightness);
fflush(stdout);
}
else
{
printf("%s\n", "100.00%");
fflush(stdout);
}
}
}
if (!get && !set)
{
/* `stty icanon echo` */
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty))
{
perror(*argv);
return 1;
}
/* Show cursor */
printf("%s", "\033[?25h");
fflush(stdout);
}
return 0;
}
/**
* Test whether a string numerical and with at most two trailing '%'
*
* @param str The string
* @return Whether the test passed
*/
static int isnumerical(const char* str)
{
int p = 0, d = 0;
if ((*str == 0) || (*str == '%'))
return 0;
for (; *str; str++)
{
switch (*str)
{
case '.':
if (d++)
return 0;
/* fall through */
case '0' ... '9':
if (p)
return 0;
break;
case '%':
p++;
break;
default:
return 0;
}
}
return p <= 2;
}
/**
* Interactively adjust the backlight on a device
*
* @param cols The number of columns on the terminal
* @param device The device on which to adjust backlight
*/
static void adjust(int cols, const char* device)
{
int min, max, cur, step, init, i, d;
size_t lendir;
char* dir = alloca(PATH_MAX * sizeof(char));
char* buf = alloca(256 * sizeof(char));
*dir = 0;
dir = strcat(dir, BACKLIGHT_DIR "/");
dir = strcat(dir, device);
dir = strcat(dir, "/");
lendir = strlen(dir);
/* Get brightness parameters */
min = 0;
if (readfile(buf, strcat(dir, "max_brightness")))
return;
max = atoi(unnl(buf));
*(dir + lendir) = 0;
if (readfile(buf, strcat(dir, "brightness")))
return;
cur = atoi(unnl(buf));
if (max <= min)
return; /* what the buck */
step = (max - min) / 200 ?: 1;
init = cur;
P("\n\n\n\n\n");
bars(min, max, init, cur, cols);
while ((d = getchar()) != -1)
switch (d)
{
case 'q':
case '\n':
case 4:
P("");
return;
case 'A':
case 'C':
cur += step << 1;
/* fall through */
case 'B':
case 'D':
cur -= step;
if (cur < min) cur = min;
if (cur > max) cur = max;
if (writefile(buf, cur, dir))
return;
bars(min, max, init, cur, cols);
}
}
/**
* Gets the current backlight setting on a device
*
* @param device The device from which to get backlight
* @return The brightness as a [0; 1] float, negative on error
*/
static float getbrightness(const char* device)
{
int min, max, cur, i;
size_t lendir;
char* dir = alloca(PATH_MAX * sizeof(char));
char* buf = alloca(256);
*dir = 0;
dir = strcat(dir, BACKLIGHT_DIR "/");
dir = strcat(dir, device);
dir = strcat(dir, "/");
lendir = strlen(dir);
/* Get brightness parameters */
min = 0;
if (readfile(buf, strcat(dir, "max_brightness")))
return -1.f;
max = atoi(unnl(buf));
*(dir + lendir) = 0;
if (readfile(buf, strcat(dir, "brightness")))
return -1.f;
cur = atoi(unnl(buf));
if (max <= min)
return -1.f; /* what the buck */
return (float)cur / (float)(max - min);
}
/**
* Sets the current backlight setting on a device
*
* @param device The device from which to get backlight
* @param adjustment The adjustment to make
*/
static void setbrightness(const char* device, const char* adjustment)
{
int min, max, cur, i, adj;
size_t lendir;
char* dir = alloca(PATH_MAX * sizeof(char));
char* buf = alloca(256);
int act = 0, integer = 0, decimal = 0, p = 0, d = 0;
*dir = 0;
dir = strcat(dir, BACKLIGHT_DIR "/");
dir = strcat(dir, device);
dir = strcat(dir, "/");
lendir = strlen(dir);
/* Get brightness parameters */
min = 0;
if (readfile(buf, strcat(dir, "max_brightness")))
return;
max = atoi(unnl(buf));
*(dir + lendir) = 0;
if (readfile(buf, strcat(dir, "brightness")))
return;
cur = atoi(unnl(buf));
if (max <= min)
return; /* what the buck */
/* Read -/+/= head */
if (*adjustment == '-')
act = -1;
else if (*adjustment == '+')
act = 1;
else if (*adjustment != '=')
adjustment--;
adjustment++;
/* Parse numerical part */
for (; *adjustment && (*adjustment != '%'); adjustment++)
if (*adjustment == '.')
d = 1;
else if (d)
{
if ((d * 10 < 0) || (decimal * 10 + 9 < 0)) /* stop if the precision is too high */
continue;
d *= 10;
decimal *= 10;
decimal += (*adjustment) - '0';
}
else
{
integer *= 10;
integer += (*adjustment) - '0';
}
if (!d)
d = 1;
/* Count number of p:s */
while (*adjustment++)
p++;
/* Calculate value to send */
if (p == 0)
adj = integer + (int)((double)decimal / (double)d + 0.5d);
else if (p == 1)
adj = (int)(((double)integer + (double)decimal / (double)d) * (double)(max - min) / 100.d);
else
adj = (int)(((double)integer + (double)decimal / (double)d) * (double)cur / 100.d);
adj = (act & 1) * cur + (act | 1) * adj;
if (adj < min) adj = min;
if (adj > max) adj = max;
/* Send value */
writefile(buf, adj, dir);
}
/**
* Read a file
*
* @param output Buffer to store the file's content in
* @param file The file to read
* @return Zero on success, non-zero on failure
*/
static int readfile(char* output, const char* file)
{
#define BLOCK_SIZE 256 /* We will not even encounter that much */
FILE* f;
size_t got, have = 0;
int ended = 0;
if ((f = fopen(file, "r")) == NULL)
{
perror(file);
return -1;
}
while (!ended)
{
got = fread(output + have, 1, BLOCK_SIZE, f);
if (got != BLOCK_SIZE)
{
ended = feof(f);
have += got;
clearerr(f);
fclose(f);
if (!ended)
{
perror(file);
return -1;
}
}
else
have += got;
}
*(output + have) = 0;
return 0;
}
/**
* Write an integer to a file
*
* @param buffer Buffer for temporary data
* @param integer The integer to write
* @param file The file to which to write
* @return Zero on success, non-zero on failure
*/
static int writefile(char* buffer, int integer, const char* file)
{
FILE* f;
size_t n = 0;
buffer += 32;
do
{
*(buffer - n++) = (integer % 10) + '0';
integer /= 10;
}
while (integer);
buffer -= n - 1;
*(buffer + n++) = '\n';
if ((f = fopen(file, "w")) == NULL)
{
perror(file);
return -1;
}
if (fwrite(buffer, 1, n, f) != n)
{
perror(file);
fclose(f);
return -1;
}
fflush(f);
fclose(f);
return 0;
}
/**
* Print the status
*
* @param min The minimum possible brightness
* @param max The maximum possible brightness
* @param init The brightness used when the program started
* @param cur The current brightness
* @param cols The number of columns on the terminal
*/
static void bars(int min, int max, int init, int cur, int cols)
{
int mid = (int)((cur - min) * (float)(cols - 2) / (float)(max - min) + 0.5f);
printf("\033[1000D\033[6A");
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: %i\n", max);
printf("\033[2KInitial brightness: %i\n", init);
printf("\033[2KCurrent brightness: %i\n", cur);
fflush(stdout);
}
