added files

Makefile

@@ -0,0 +1,10 @@
+CC=gcc
+CFLAGS=-std=c89 -pedantic -Wall
+
+debug:clean
+	$(CC) $(CFLAGS) -g -o light main.c
+stable:clean
+	$(CC) $(CFLAGS) -o light main.c
+clean:
+	rm -vfr *~ light
+	

main.c

@@ -0,0 +1,379 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+
+typedef enum LBOOL{
+	TRUE = 0,
+	FALSE = 1
+} LBOOL;
+
+typedef enum LOPTYPE{
+	SET = 0,
+	ADD = 1,
+	SUB = 2
+} LOPTYPE;
+
+/* Flags */
+LBOOL q; /* Quiet, supresses output */
+LBOOL c; /* print unprecise current value in percentage */
+LBOOL m; /* read max value*/
+LBOOL p; /* precision read current value */
+int wbright;
+LOPTYPE ot;
+
+LBOOL readint(const char* f, unsigned int *i){
+	FILE* ff = fopen(f, "r");
+	if(ff){
+		fscanf(ff, "%u", i);
+		fclose(ff);
+		return TRUE;
+	}else{
+		return FALSE;
+	}
+}
+
+LBOOL writeint(const char* f, unsigned int i){
+	FILE* ff = fopen(f, "w");
+	if(ff){
+		fprintf(ff, "%u", i);
+		fclose(ff);
+		return TRUE;
+	}else{
+		return FALSE;
+	}
+}
+
+
+LBOOL is_dir(const char* d){
+	DIR* dd = opendir(d);
+	if(dd){
+		closedir(dd);
+		return TRUE;
+	}else{
+		return FALSE;
+	}
+}
+
+LBOOL is_writable(const char* f){
+	FILE* dd = fopen(f, "w");
+	if(dd){
+		fclose(dd);
+		return TRUE;
+	}else{
+		return FALSE;
+	}	
+}
+
+typedef struct {
+	char*		name;
+	unsigned int	current_brightness;
+	unsigned int	max_brightness;
+	char*		c_path; /* Controller-path */
+	char*		cb_path; /* Current brightness-path */
+	char*		mb_path; /* Max brightness-path */
+	char*		b_path; /* Brightness-path */
+	enum LBOOL		is_ok;
+} controller;
+
+typedef struct {
+	controller	controllers[256];
+	unsigned int	num_controllers;
+} fetch_result;
+
+
+fetch_result fetch_controllers(const char* ctrldir){
+	fetch_result returner;
+	struct dirent* ep;
+
+	DIR* lcdir = opendir(ctrldir);
+	
+	returner.num_controllers = 0;
+
+	if(!lcdir){
+		if(q == FALSE)
+			printf("Error: Could not open directory '%s'!\n", ctrldir);
+	}else{
+		while( ( ep = readdir(lcdir) ) ){
+			char* currctrldir = "";
+			char* currctrldir_curr = "";
+			char* currctrldir_max = "";
+			char* currctrldir_f = "";
+			if( ep->d_name[0] != '.'){
+				returner.controllers[returner.num_controllers].name = ep->d_name;
+				
+				/* Set some default values, in case something fails we dont just get null */
+				returner.controllers[returner.num_controllers].current_brightness = 0;
+				returner.controllers[returner.num_controllers].max_brightness = 0;
+				returner.controllers[returner.num_controllers].is_ok = TRUE;
+				returner.controllers[returner.num_controllers].c_path = NULL;
+				returner.controllers[returner.num_controllers].cb_path = NULL;
+				returner.controllers[returner.num_controllers].b_path = NULL;
+				returner.controllers[returner.num_controllers].mb_path = NULL;
+				
+				/* Get path to the current controller dir */
+				asprintf(&currctrldir, "%s/%s", ctrldir, ep->d_name);
+				returner.controllers[returner.num_controllers].c_path = currctrldir;
+				if(is_dir(currctrldir) == FALSE){
+					if(q == FALSE)
+						printf("Warning: '%s' is not a directory, check your system.\n", currctrldir);
+					returner.controllers[returner.num_controllers].is_ok = FALSE;
+				}
+				
+				/* Get path to current actual_brightness-file */
+				asprintf(&currctrldir_curr, "%s/%s", currctrldir, "actual_brightness");
+				returner.controllers[returner.num_controllers].cb_path = currctrldir_curr;
+				if( readint(currctrldir_curr, &returner.controllers[returner.num_controllers].current_brightness) == FALSE ){
+					if(q == FALSE)
+						printf("Warning: Can't read actual_brightness-file of '%s'. Will ignore this controller.\n", ep->d_name);
+					returner.controllers[returner.num_controllers].is_ok = FALSE;
+				}				
+				
+				/* Get path to current max_brightness-file*/
+				asprintf(&currctrldir_max, "%s/%s", currctrldir, "max_brightness");
+				returner.controllers[returner.num_controllers].mb_path = currctrldir_max;
+				if( readint(currctrldir_max, &returner.controllers[returner.num_controllers].max_brightness) == FALSE ){
+					if(q == FALSE)
+						printf("Warning: Can't read max_brightness-file of '%s'. Will ignore this controller.\n", ep->d_name);
+					returner.controllers[returner.num_controllers].is_ok = FALSE;
+				}
+				
+				/* Get path to current brightness-file */
+				asprintf(&currctrldir_f, "%s/%s", currctrldir, "brightness");
+				returner.controllers[returner.num_controllers].b_path = currctrldir_f;
+				if( is_writable(currctrldir_f) == FALSE){
+					if(q == FALSE)
+						printf("Warning: Controllerfile of '%s' is not writable. Will ignore this controller.\n", ep->d_name);
+					returner.controllers[returner.num_controllers].is_ok = FALSE;
+				}
+				
+				
+				returner.num_controllers++;
+			}
+		}
+		closedir(lcdir);	
+	}
+	return returner;
+}
+
+controller* get_best_controller(fetch_result* res){
+	unsigned int it;
+	unsigned int cmax;
+	LBOOL foundokctrl;
+	controller* returner;
+	
+	
+	it = 0;
+	cmax = 0;
+	foundokctrl = FALSE;
+	
+	returner = NULL;
+	
+	while(it < res->num_controllers){
+		if(res->controllers[it].is_ok == TRUE){
+			if(foundokctrl != TRUE){
+				foundokctrl = TRUE;
+				returner = &res->controllers[it];
+			}
+			if(res->controllers[it].max_brightness > cmax){
+				cmax = res->controllers[it].max_brightness;
+				returner = &res->controllers[it];
+			}
+		}
+		it++;
+	}
+	
+	return returner;
+}
+
+void usage(){
+	printf("Usage: light [-qcas] <value>\n\n\t-q:\t Run quiet, supresses output.\n\t-c:\t Prints the current brightness in percent and exits.(Not precise)\n\t-p:\t Prints the current brightness directly from controller and exits. (Precise)\n\t-m:\t Prints the max brightness directly from controller and exits. (To be used side-by-side with -p)\n\t-a:\t Add the value instead of setting it.\n\t-s:\t Subtract the value instead of setting it.\n\n\t<value>\t Brightness wanted in percent.\n\n");
+}
+
+int main(int argc, char **argv) {
+	unsigned int argsit;
+	
+	fetch_result	res;
+	controller*	best_ctrl;
+	unsigned int	citr;
+	uid_t		uid;
+	unsigned int	minlight;
+	LBOOL		given;
+	unsigned int	real_wbright;
+	unsigned int	minlight_nonp;
+	unsigned int	curr_bright;
+	unsigned int	curr_brightp;
+	
+	
+	/* Get UID */
+	uid = getuid();
+	
+	/* Parse arguments */
+	q=FALSE;
+	c=FALSE;
+	m=FALSE;
+	p=FALSE;
+	ot=SET;
+	wbright=0;
+	argsit = 1;
+	given=FALSE;
+	while(argsit < argc){
+		char* carg = argv[argsit];
+		if(carg[0] == '-'){
+			unsigned int cargit = 1;
+			while(cargit < strlen(carg)){
+				switch(carg[cargit]){
+					case 'q':
+						q = TRUE;
+					break;
+					case 'a':
+						ot = ADD;
+					break;
+					case 's':
+						ot = SUB;
+					break;
+					case 'c':
+						c = TRUE;
+					break;
+					case 'p':
+						p = TRUE;
+					break;
+					case 'm':
+						m = TRUE;
+					break;
+					default:
+					break;
+				}
+				cargit++;
+			}
+		}else{
+			wbright = atoi(carg);
+			given=TRUE;
+		}
+		
+		argsit++;
+	}
+	
+	if(c == TRUE || m == TRUE || p == TRUE){
+		q = TRUE;
+	}
+	
+	if(given == FALSE && c == FALSE && m == FALSE && p == FALSE){
+		usage();
+		return 0;
+	}
+	if(q == FALSE)
+		printf("Light v0.4 - Fredrik Haikarainen\n");
+	
+	/* Get and check minlight */
+	
+	if(readint("/etc/light/minlight", &minlight) == FALSE){
+		minlight = 5;
+		if(q == FALSE)
+			printf("Warning: Couldn't read /etc/light/minlight, using 5 as default.\n");
+	}
+	
+	/* Fetch controllers */
+	if(q == FALSE)
+		printf("Fetching controllers..\n");
+	
+	res = fetch_controllers("/sys/class/backlight");
+	
+	citr = 0;
+	while(citr < res.num_controllers){
+		controller* currc = &res.controllers[citr];
+		if(currc->is_ok == TRUE){
+			if(q == FALSE)
+				printf("\tFound '%s' (%u/%u)\n", currc->name, currc->current_brightness, currc->max_brightness);
+		}else{
+			if(q == FALSE)
+				printf("\tFound '%s', but ignoring\n", currc->name);
+		}
+		citr++;
+	}
+
+	if(q == FALSE)
+		printf("\n");
+	
+	/* Get the best controller */
+	best_ctrl = get_best_controller(&res);
+	
+	if(best_ctrl == NULL){
+		if(uid == 0){
+			if(q == FALSE)
+				printf("No okay controller found, even though you are root! Check your system.\n");
+		}else{
+			if(q == FALSE)
+				printf("No okay controller found, check your permissions or try to run as root.\n");
+		}
+		return 1;
+	}
+	
+	if(p == TRUE){
+		printf("%u\n", best_ctrl->current_brightness);
+		return 0;
+	}
+	
+	if(m == TRUE){
+		printf("%u\n", best_ctrl->max_brightness);
+		return 0;
+	}
+	
+	if(q == FALSE)
+		printf("Using controller '%s' ..\n", best_ctrl->name);
+	
+	if(wbright < 0){ wbright = 0;}
+	if(wbright > 100){wbright=100;}
+	
+	curr_bright = best_ctrl->current_brightness;
+	curr_brightp = (float)((float)curr_bright / (float)best_ctrl->max_brightness) * 100;
+	
+	
+	if(c == TRUE){
+		printf("%u\n", curr_brightp);
+		return 0;
+	}
+	
+	switch(ot){
+		case SET:
+			real_wbright = best_ctrl->max_brightness * ( (float)wbright / 100 );
+		break;
+		case ADD:
+			real_wbright = ( best_ctrl->max_brightness * ( (float)( curr_brightp + wbright +1) / 100 ));
+		break;
+		case SUB:
+			real_wbright = ( best_ctrl->max_brightness * ( (float)( curr_brightp - wbright + 1) / 100 ));
+		break;
+		default:
+		break;
+	}
+	
+	minlight_nonp = best_ctrl->max_brightness * ( (float)minlight / 100);
+
+	/* FIXME 
+		Line below makes sure the value never wraps around and gets higher. Puts a (high) limit on max brightness.
+		Not sure if safe for portabilities sake.
+	 */
+	if(real_wbright > ((UINT_MAX/2) - best_ctrl->max_brightness)){ real_wbright = minlight_nonp; } 
+	
+	
+	
+	if(real_wbright > best_ctrl->max_brightness){real_wbright = best_ctrl->max_brightness;}
+	if(real_wbright < minlight_nonp){real_wbright = minlight_nonp;}
+	
+	if(q == FALSE)
+		printf("Writing %u to file '%s'..\n", real_wbright, best_ctrl->b_path);
+	
+	if(writeint(best_ctrl->b_path, real_wbright) == FALSE){
+		if(q == FALSE){
+			printf("Error: Could not write to file %s, check your permissions!\n", best_ctrl->b_path);
+		}
+		return 1;
+	}
+	
+	return 0;
+}