SPIFFS_SysLogger

A system Logger Library for the ESP micro controller chips that uses SPIFFS

setup your code

You need to include "SPIFFS_SysLogger.h"

#include "SPIFFS_SysLogger.h"

Then you need to create the ESPSL object

ESPSL sysLog;

In setup() add the following code to create or open a log file of 100 lines, 80 chars/line

   SPIFFS.begin();
   .
   .
   if (!sysLog.begin(100, 80)) 
   {
     Serial.println("sysLog.begin() error!");
     delay(10000);
   }

Adding an entry to the system log

   sysLog.write("This is a line of text");

or

   sysLog.writef("This is line [%d] of [%s]", __LINE__, __FUNCTION__);

To read the sytem log file you first have to tell the SPIFFS_SysLogger to start reading:

   sysLog.startReading();

To read the sytem log file from the jongest to the latest log line you call the readNextLine() method:

   char lLine[100] = {0};
   Serial.println("\n=====from oldest to end==============================");
   sysLog.startReading();
   while( sysLog.readNextLine(lLine, sizeof(lLine)) )
   {
     Serial.printf("==>> [%s]\r\n", lLine);
   }

To read the sytem log file in reversed order you call the readPreviousLine() method:

   char lLine[100] = {0};
   Serial.println("\n=====from end to oldest==============================");
   sysLog.startReading();
   while( sysLog.readPreviousLine(lLine, sizeof(lLine)) )
   {
     Serial.printf("==>> [%s]\r\n", lLine);
   }

With a simple macro you can add Debug info to your log-lines

  /* example of debug info with time information ----------------------------------------------*/
  #define writeToSysLog(...) ({ sysLog.writeDbg(sysLog.buildD("[%02d:%02d:%02d][%-12.12s] "     \
                                                               , hour(), minute(), second()     \
                                                               , __FUNCTION__)                  \
                                         ,__VA_ARGS__); })

or

  /* example of debug info with calling function and line in calling function -----------------*/
  #define writeToSysLog(...) ({ sysLog.writeDbg(sysLog.buildD("[%-12.12s(%4d)] "                \
                                                               , __FUNCTION__, __LINE__)        \
                                         ,__VA_ARGS__); })

This Logline:

     writeToSysLog("Reset Reason [%s]", ESP.getResetReason().c_str());

looks like this wth the first writeToSysLog() example (the first line):

   [12:30:22][setup       ] Reset Reason [External System] 

the macro add's the time, and the function-name that called this writeToSysLog() macro

   [12:30:22][setup       ] <rest of the log text>

Methods

ESPSL::begin(uint16_t depth, uint16_t lineWidth)

Opens an existing system logfile. If there is no system logfile or the depth or lineWidth the logfile was created with are not the same it will create a logfile with depth lines each lineWidth chars wide.

• The max. lineWidth is 150 chars
• The min. lineWidth is 50 chars
• The min. depth is 10 lines

Return boolean. **true** if succeeded, otherwise **false**

ESPSL::begin(uint16_t depth, uint16_t lineWidth, boolean mode)

if mode is true:
It will create a new system logfile with depth lines each lineWidth chars wide.
if mode is false:
Opens an existing system logfile. If there is no system logfile it will create one with depth lines each lineWidth chars wide.
Return boolean. true if succeeded, otherwise false

ESPSL::status()

Display some internal var's of the system logfile to Serial.

ESPSL::setOutput(HardwareSerial *serIn, int baud)

Set the debug output to serIn.

ESPSL::setOutput(Stream *serIn)

Set the debug output to serIn.

ESPSL::print(const char *line)

Prints the line to serIn.

ESPSL::println(const char *line)

Prints the line to serIn (and add a '\n' at the end)

ESPSL::printf(const char *fmt, ...)

Prints formatted line to serIn

ESPSL::write(const char*)

This method will write a line of text to the system logfile.
Return boolean. true if succeeded, otherwise false

ESPSL::writef(const char *fmt, ...)

This method will write a formatted line of text to the system logfile. The syntax is the same as printf().
Return boolean. true if succeeded, otherwise false

ESPSL::writeDbg(const char *dbg, const char *fmt, ...)

This method will write a formatted line of text to the system logfile but with a string in front of it. This 'string' can be formatted using ESPSL::build(). The syntax for *fmt, ... is the same as printf(). This method is ment to be used with the writeToSysLog() macro.
Return boolean. true if succeeded, otherwise false

ESPSL::buildD(const char *fmt, ...)

This method will return a formatted line of text. The syntax for *fmt, .. is the same as printf(). This method is ment to be used to 'feed' the ESPSL:writeDbg() method.
Return char*.

ESPSL::startReading()

Sets the read pointer to startLine and the end pointer to startLine + numLines.
This method should be called before using readNextLine() or readPreviousLine().
Return boolean. true if succeeded, otherwise false

ESPSL::readNextLine()

Reads the next line from the system logfile and advances the read pointer one line.
Return bool. true if more records available, otherwise false.

ESPSL::readPreviousLine()

Reads the previous line from the system logfile and moves the read pointer one line back.
Return bool. true if more records available, otherwise false.

ESPSL::dumpLogFile()

This method is for debugging. It display's all the lines in the system logfile to Serial.
Return boolean. true if succeeded, otherwise false

ESPSL::removeSysLog()

This methos removes a system logfile from SPIFFS.
Return boolean. true if succeeded, otherwise false

ESPSL::getLastLineID()

Internaly the ESP_SysLogger uses sequential lineID's to uniquely identify each log line in the file. With this method you can query the last used lineID.
Return uint32_t. Last used lineID.

ESPSL::setDebugLvl(int8_t debugLvl)

If _DODEBUG is defines in the ESP_SysLogger.h file you can use this method to set the debug level to display specific Debug lines to Serial.

... more to come