#SimpleLogger
NOTE: This project was made primarily as a learning exercise, and will neither be maintained nor should be used in a production environment. (See Caveats for more info)
A basic, easy to use logger for output of messages at various logging levels with date/time stamp to standard out and a defined log file.
This project has been modified by seed93.
##Features
- Time/date stamped output
- File and line number output
- Console output is colored according to the level of the log message
- Error levels automatically print errno if it has been set
- Variable length argument list
- Supports writing of stacktraces. Stacktraces are "prettyfied" to give the user an easiear to read trace
- Has an option to wrap messages over 80 characters to multiple lines
- Written in C, for use in C and C++ projects
##Caveats
- Not thread safe
- Not signal safe
- Currently does not have millisecond granularity in timestamp
##Building with SimpleLogger
Include simplog.h in your project files, and please refer to example.c:
#include "simplog.h"
Run make to build an example.
You're all set! Check out the Usage section below for how to use SimpleLogger in your program.
##Usage
Each message must be accompanied by a level. Supported levels are:
_FATAL_ = -2 : A fatal error has occured, the program will exit immediately
_ERROR_ = -1 : An error has occured, the program may not exit
_INFO_ = 0 : Nessessary information regarding program operation
_WARN_ = 1 : Any circumstance that may not affect normal operation
_DEBUG_ = 2 : Standard debug messages
_VERBOSE_ = 3 : All debug messages
Here is an example of how to create a log entry:
LOG( <desired_level>, "Message", <var-args> );
For example, to recreate part of the output in the screenshot above:
LOG(_VERBOSE_, "verbose");
LOG(_DEBUG_, "testing");
LOG(_WARN_, "testing");
LOG(_INFO_, "testing");
LOG(_ERROR_, "testing");
LOG(_FATAL_, "testing");
To write a stacktrace, just call:
STACKTRACE();
Stacktraces will automatically "prettyfied" to provide easier to read traces.
NOTE: Pretty stacktraces are currently broken on MacOS, and will fallback to standard backtrace output.
If you want to load a config file to setup the logger:
simplog.loadConfig( <desired-config-file> );
With a config that can use any of the following options:
silent=<true-or-false> // Sets the silent mode
wrap=<true-or-false> // Sets if too long lines are wrapped
flush=<true-or-false> // If the log file should be flushed or not
debug=<0-to-3> // Set the debug level, 0 - 3
logfile=<logfile-path> // Set the path to the logfile to output to
There are individual functions to set each of these parameters manually as well. See the documentation below.
##Documentation
###writeLog
/*
Writes output to defined logfile and standard out/err with
date/time stamp and associated log level.
Can take formatted string like printf, with a variable sized list of
arguments.
Prints errno when appropriate.
Always adds new line to output.
Logging Levels:
-2 : Fatal - A fatal error has occured: program will exit immediately
-1 : Error - An error has occured: program may not exit
0 : Info - Nessessary information regarding program operation
1 : Warnings - Any circumstance that may not affect normal operation
2 : Debug - Standard debug messages (default)
3 : Debug-Verbose - All debug messages
Input:
int loglvl - The desired output logging level. See above table for levels
const char* str - The message to be output. This is a format string
... - Variable length list of arguments to be used with the format string (optional)
*/
void writeLog( int loglvl, const char* str, ... );
###writeStackTrace
/*
Prints the stacktrace to logs for the current location in the program.
Most recent calls appear first.
Set to a max of 15 lines of the stacktrace for output.
*/
void writeStackTrace();
###loadConfig
/*
Loads logger configuration settings from the given config file.
Supported settings are:
silent - Enables/disables silent mode (see setLogSilentMode)
wrap - Enables/disables line wrapping (see setLineWrap)
flush - Determines if the log file should be cleared (see flushLog)
debug - Sets the debug level (see setLogDebugLevel)
logfile - Sets the path to the log file (see setLogFile)
Input:
const char* config - Logger config file to parse and load settings from
*/
void loadConfig( const char* config );
###setLogDebugLevel
/*
Sets the desired debug level for writing logs.
Debug Levels:
0 : Info - Nessessary information regarding program operation
1 : Warnings - Any circumstance that may not affect normal operation
2 : Debug - Standard debug messages (default)
3 : Debug-Verbose - All debug messages
Input:
int level - desired debug level
*/
void setLogDebugLevel( int level );
###setLogFile
/*
Sets the filename for log output.
Input:
const char* file - desired log output file
*/
void setLogFile( const char* file );
###setLogSilentMode
/*
Enables/Disables silent mode.
When silent mode is enabled, no output will be written to standard out.
Log output will continue normally.
Input:
bool silent - Desired state of silent mode: false = Disabled (default), true = Enabled
*/
void setLogSilentMode( bool silent );
###setLineWrap
/*
Enables/Disables line wrapping.
When line wrapping is enabled, lines that are over 80 characters will be
wrapped multiple times so that each line is below 80 characters.
Input:
bool wrap - Desired state of line wrapping: true = Enabled (default), false = Disabled
*/
void setLineWrap( bool wrap );
###flushLog
/*
Flushes the contents of the logfile by deleting it and recreating
a new empty logfile of the same name.
*/
void flushLog();
##Frequently Asked Questions
Q: There are already a ton of loggers out there. Why make another one?
A: The main idea behind this project was a learning experience in C while making something somewhat useful. I just wanted to make a logger that is simple and easy to use, and has output that is relatively pleasant to look at.
Q: Why don't you have feature X or Y?
A: As I said, the goal was to create a simple and easy to use logger. As such, there are probably some features this logger doesn't have when compared to some more feature rich alternatives.
Q: You did something stupid/improper in your code.
A: If there is something dumb or not proper that I did, please open an issue and let me know! Since this was largely a learning project I would love to hear about anything bad I've done here!
Q: I found a bug / I'm having problems
A: If you either found a bug or are having problems with this logger, please open an issue describing your dilema and I'll take a look!
##Promotion If you like SimpleLogger, then please star it on GitHub and share it with others!