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56 lines
1.0 KiB
56 lines
1.0 KiB
#include <stdio.h>
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#include <stdlib.h>
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#define ROOT_DIR "/sys/class/backlight/intel_backlight/"
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#define BRIGHTNESS_STEP 750
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int main(int argc, char** argv) {
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FILE* brightness = fopen(ROOT_DIR "brightness", "r+");
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if(brightness == NULL) {
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perror("fopen");
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exit(EXIT_FAILURE);
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}
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int current_brightness;
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int res = fscanf(brightness, "%d", ¤t_brightness);
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if(res != 1) {
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perror("fscanf");
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exit(EXIT_FAILURE);
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}
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if(argc != 2) {
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fprintf(stderr, "Exactly one argument is required. Got %d arguments.\n", argc);
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exit(EXIT_FAILURE);
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}
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if(*argv[1] == '+') {
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current_brightness+=BRIGHTNESS_STEP;
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} else if(*argv[1] == '-') {
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current_brightness-=BRIGHTNESS_STEP;
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} else {
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fprintf(stderr, "Argument must be '+' or '-', got %s.\n", argv[1]);
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exit(EXIT_FAILURE);
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}
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if(current_brightness < 0)
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current_brightness = 0;
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rewind(brightness);
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if(!fprintf(brightness, "%d", current_brightness)) {
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perror("fprintf");
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exit(EXIT_FAILURE);
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}
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if(fclose(brightness)) {
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perror("fclose");
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exit(EXIT_FAILURE);
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}
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return 0;
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}
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