Improve overall logging

Makefile

 MANDIR=$(PREFIX)/share/man/man1
 
 CC=gcc
-CFLAGS=-std=c89 -O2 -pedantic -Wall -I"./include"
+CFLAGS=-std=c89 -O2 -pedantic -Wall -I"./include" -D_XOPEN_SOURCE=500
 MANFLAGS=-h -h -v -V -N
 
 HELP2MAN_VERSION := $(shell help2man --version 2>/dev/null)

include/helpers.h

  * }*/
 #define LIGHT_CLAMP(x, y, z) ((x<y) ? y : ((x>z) ? z : x ));
 
-#define LIGHT_NOTE(x) if(light_verbosity > 2){printf("%s.\n", x);}
-
-#define LIGHT_WARN(x) if(light_verbosity > 1){printf("warning: \"%s\", in \"%s\" on line %u.\n", x, __FILE__, __LINE__);}
-
-#define LIGHT_ERR(x) if(light_verbosity > 0){printf("error: \"%s\", in \"%s\" on line %u.\n", x, __FILE__, __LINE__);}
-
-#define LIGHT_MEMERR() LIGHT_ERR("memory error");
-
+#define LIGHT_LOG_FMT_BUF_SIZE 1024
 /* Verbosity levels: 
  * 0 - No output
  * 1 - Errors
  * 2 - Errors, warnings 
  * 3 - Errors, warnings, notices */
-int    light_verbosity;
+typedef enum LIGHT_LOG_LEVEL {
+  LIGHT_ERROR_LEVEL = 1,
+  LIGHT_WARN_LEVEL,
+  LIGHT_NOTE_LEVEL
+} LIGHT_LOG_LEVEL;
+
+LIGHT_LOG_LEVEL light_verbosity;
+char light_log_buffer[LIGHT_LOG_FMT_BUF_SIZE];
+
+#define LIGHT_LOG(lvl,f,t,x)if(light_verbosity >= lvl){fprintf(f,t": \"%s\", in \"%s\" on line %u.\n", x, __FILE__, __LINE__);}
+
+#define LIGHT_NOTE(x)LIGHT_LOG(LIGHT_NOTE_LEVEL,stdout,"notice",x)
+
+#define LIGHT_WARN(x)LIGHT_LOG(LIGHT_WARN_LEVEL,stderr,"warning",x)
+
+#define LIGHT_ERR(x)LIGHT_LOG(LIGHT_ERROR_LEVEL,stderr,"error",x)
+
+#define LIGHT_LOG_FMT(x,s,f)if(snprintf(light_log_buffer, LIGHT_LOG_FMT_BUF_SIZE,x,s) > 0){f(light_log_buffer);}
+
+#define LIGHT_NOTE_FMT(x,s)LIGHT_LOG_FMT(x,s,LIGHT_NOTE);
+
+#define LIGHT_WARN_FMT(x,s)LIGHT_LOG_FMT(x,s,LIGHT_WARN);
+
+#define LIGHT_ERR_FMT(x,s)LIGHT_LOG_FMT(x,s,LIGHT_ERR);
+
+#define LIGHT_MEMERR() LIGHT_ERR("memory error");
+
+#define LIGHT_PERMLOG(x,f)f##_FMT("could not open '%s' for "x,filename); f("check if this file exists or if you have the right permissions");
+
+#define LIGHT_PERMERR(x) LIGHT_PERMLOG(x,LIGHT_ERR)
+
+#define LIGHT_PERMWARN(x) LIGHT_PERMLOG(x,LIGHT_WARN)
 
 /* Typedef for boolean values */
 typedef enum LIGHT_BOOL {

src/helpers.c

 
   if(!fileHandle)
   {
-    LIGHT_ERR("could not open file for reading");
+    LIGHT_PERMERR("reading");
     return FALSE;
   }
 
   if(fscanf(fileHandle, "%u", &iCopy) != 1)
   {
-    LIGHT_ERR("file contents are corrupt");
+    LIGHT_ERR_FMT("Couldn't parse a positive integer number from '%s'", filename);
     fclose(fileHandle);
     return FALSE;
   }
 
   if(!fileHandle)
   {
-    LIGHT_ERR("could not open file for writing");
+    LIGHT_PERMERR("writing");
     return FALSE;
   }
 
 
   if(!fileHandle)
   {
-    LIGHT_ERR("could not open file for reading");
+    LIGHT_PERMERR("reading");
     return FALSE;
   }
 
   if(fscanf(fileHandle, "%lu", &iCopy) != 1)
   {
-    LIGHT_ERR("file contents are corrupt");
+    LIGHT_ERR_FMT("Couldn't parse a positive integer number from '%s'", filename);
     fclose(fileHandle);
     return FALSE;
   }
 
   if(!fileHandle)
   {
-    LIGHT_ERR("could not open file for writing");
+    LIGHT_PERMERR("writing");
     return FALSE;
   }
 
 
   if(!fileHandle)
   {
-    LIGHT_ERR("could not open file for reading");
+    LIGHT_PERMERR("reading");
     return FALSE;
   }
 
 
   if(!fileHandle)
   {
+    LIGHT_PERMWARN("writing");
     return FALSE;
   }
 
 
   if(!fileHandle)
   {
+    LIGHT_PERMWARN("reading");
     return FALSE;
   }
 

src/light.c

 LIGHT_BOOL light_parseArguments(int argc, char** argv)
 {
   int currFlag;
+  int verbosity;
 
   LIGHT_BOOL opSet = FALSE;
   LIGHT_BOOL targetSet = FALSE;
           light_printHelp();
           return FALSE;
         }
-        if(sscanf(optarg, "%i", &light_verbosity) != 1)
+        if(sscanf(optarg, "%i", &verbosity) != 1)
         {
           printf("-v Verbosity is not specified in a recognizable format.\n\n");
           light_printHelp();
           return FALSE;
         }
-        if(light_verbosity < 0 || light_verbosity > 3)
+        if(verbosity < 0 || verbosity > 3)
         {
           printf("-v Verbosity has to be between 0 and 3.\n\n");
           light_printHelp();
           return FALSE;
         }
+        light_verbosity = (LIGHT_LOG_LEVEL)verbosity;
         break;
     }
   }
   }
   else if(!light_controllerAccessible(light_Configuration.specifiedController))
   {
-    LIGHT_ERR("selected controller is not valid, make sure this application is run as root.");
+    LIGHT_ERR_FMT("selected controller '%s' is not valid",
+                  light_Configuration.specifiedController);
     return FALSE;
   }
 
-
   return TRUE;
 }
 
   }
 
   /* Prepare variables */
+  LIGHT_NOTE_FMT("Executing light on '%s' controller", light_Configuration.specifiedController);
 
   /* -- First, get the current, min and max values directly from controller/configuration (raw values) */
   if(!light_getBrightness(light_Configuration.specifiedController, &rawCurr))
 
   if( hasMinCap && minCap > rawMax )
   {
-    LIGHT_WARN("invalid minimum cap for controller, ignoring and using 0");
+    LIGHT_WARN_FMT("invalid minimum cap (raw) value of '%lu' for controller, ignoring and using 0", minCap);
+    LIGHT_WARN_FMT("minimum cap must be inferior to '%lu'", rawMax);
     minCap = 0;
   }
 
       /* If we are not attempting to set, fail! */
       if(light_Configuration.operationMode != LIGHT_SET)
       {
-        printf("Minimum cap can only be used with get/set operations.\n");
+        fprintf(stderr, "Minimum cap can only be used with get/set operations.\n");
         return FALSE;
       }
 
 
     }else{
       /* If we didn't provide a valid target for write operations, fail. */
-      printf("set/add/subtract operations are only available for brightness and minimum cap files.\n");
+      fprintf(stderr, "set/add/subtract operations are only available for brightness and minimum cap files.\n");
       return FALSE;
     }
   }
     return TRUE;
   }
 
-  printf("Controller: %s\nValueRaw: %lu\nValuePercent: %.2f\nOpMode: %u\nValMode: %u\nTarget: %u\n\n", light_Configuration.specifiedController, light_Configuration.specifiedValueRaw, light_Configuration.specifiedValuePercent, light_Configuration.operationMode, light_Configuration.valueMode, light_Configuration.target);
+  fprintf(stderr, "Controller: %s\nValueRaw: %lu\nValuePercent: %.2f\nOpMode: %u\nValMode: %u\nTarget: %u\n\n", light_Configuration.specifiedController, light_Configuration.specifiedValueRaw, light_Configuration.specifiedValuePercent, light_Configuration.operationMode, light_Configuration.valueMode, light_Configuration.target);
 
-  printf("You did not specify a valid combination of commandline arguments. Have some help: \n");
+  fprintf(stderr, "You did not specify a valid combination of commandline arguments. Have some help: \n");
   light_printHelp();
   return FALSE;
 }
   {
     return FALSE;
   }
-  LIGHT_NOTE(brightnessPath)
+
   readVal = light_readULong( brightnessPath , v);
   free(brightnessPath);
 
     }
     if(light_iteratorDir == NULL)
     {
-      LIGHT_ERR("could not open backlight or leds directory");
+      LIGHT_ERR("could not open backlight or leds directory in /sys/class");
       return FALSE;
     }
   }
   {
     unsigned long currVal = 0;
 
+    LIGHT_NOTE_FMT("found '%s' controller", light_currentController);
     if(light_controllerAccessible(light_currentController))
     {