MessLogger

The class MessLogger provides methods for logging messages of different types, “status”, “warning”, “error”, “display”.

In the log file, these messages can have different colors and different prefixes.

All the logXXX() methods can be called like printf.

MessLogger is realized as a singleton.

Code:
MessLogger.h
MessLogger.cpp
MessLoggerT.h

Methods

create

static MessLogger *create(const std::string sFileName="");

Create the MessLogger singleton for output to sFileName.

sFileName

File to write to.

free

static void free();

Delete the singleton (closes the log file).

logStatus

template<typename... Args>
static void logStatus(const std::string sFormat, Args... args);
Writes a status message to the log file. If colors are set, it is green. If prefixes are set, a “S:” will be prepended to the message.
Instead of MessLogger::logStatus you can use LOG_STATUS.

logWarning

template<typename... Args>
static void logWarning(const std::string sFormat, Args... args);
Writes a warning message to the log file. If colors are set, it is blue. If prefixes are set, a “W:” will be prepended to the message.
Instead of MessLogger::logWarning you can use LOG_WARNING.

logError

template<typename... Args>
static void logError(const std::string sFormat, Args... args);
Writes an error message to the log file. If colors are set, it is red. If prefixes are set, a “E:” will be prepended to the message.
Instead of MessLogger::logError you can use LOG_ERROR.

logDisp

template<typename... Args>
static void logDisp(const std::string sFormat, Args... args);
Writes a display message to the log file. If colors are set, it is purple. If prefixes are set, a “D:” will be prepended to the message.
Instead of MessLogger::logDisp you can use LOG_DISP.

logStatus2

template<typename... Args>
static void logStatus2(const std::string sFormat, Args... args);
Writes a status message to the log file and to stdout. If colors are set, it is green. If prefixes are set, a “S:” will be prepended to the message.
Instead of MessLogger::logStatus2 you can use LOG_STATUS2.

logWarning2

template<typename... Args>
static void logWarning2(const std::string sFormat, Args... args);
Writes a warning message to the log file and to stdout. If colors are set, it is blue. If prefixes are set, a “W:” will be prepended to the message.
Instead of MessLogger::logWarning2 you can use LOG_WARNING2.

logError2

template<typename... Args>
static void logError2(const std::string sFormat, Args... args);
Writes an error message to the log file and to stdout. If colors are set, it is red. If prefixes are set, a “E:” will be prepended to the message.
Instead of MessLogger::logError2 you can use LOG_ERROR2.

logDisp2

template<typename... Args>
static void logDisp2(const std::string sFormat, Args... args);
Writes a display message to the log file and to stdout. If colors are set, it is purple. If prefixes are set, a “D:” will be prepended to the message.
Instead of MessLogger::logDisp2 you can use LOG_DISP2.

showLog

static void showLog(const std::string sLogFile, int iWhat);

Prints the specified log file to stdout.

sLogFile

The log file do display.

iWhat

Which types of messages to show. iWhat can be MessLogger::SHOW_NONE, MessLogger::SHOW_ALL or an or-ed combination of any of MessLogger::SHOW_STATUS, MessLogger::SHOW_WARNING, MessLogger::SHOW_ERROR, and MessLogger::SHOW_DISP.

showLog

static void showLog(int iWhat);

Prints the current log file to stdout.

iWhat

Which types of messages to show. iWhat can be MessLogger::SHOW_NONE, MessLogger::SHOW_ALL or an or-ed combination of any of MessLogger::SHOW_STATUS, MessLogger::SHOW_WARNING, MessLogger::SHOW_ERROR, and MessLogger::SHOW_DISP.

getNumStatus

static int getNumStatus();

Returns the number of logged status messages.

getNumWarning

static int getNumWarning();

Returns the number of logged warning messages.

getNumError

static int getNumError();

Returns the number of logged error messages.

getNumDisp

static int getNumDisp();

Returns the number of logged disp messages.

Protected Methods

constructor

MessLogger(const std::string sLogFileName);

The constructor open the output file for writing.

destructor

~MessLogger();

The destructor closes the output file.

write

void write(const std::string sLine0, const std::string sPre, const std::string sPost);

Writes a line with specified prefx and suffix. Usually prefix and suffix arte color codes.

coloredLine

static void coloredLine(std::string sLine, int iWhat);

Colors a line depending on the prefix.

logSpecial

template<typename... Args>
static void logSpecial(const std::string sHeader, const std::string sColor, const std::string sFormat, Args... args);

Writes a colored line to the log file.

Example

Compile with

g++ ml_example.cpp MessLogger.cpp xha_strutils.cpp xha_strutilsT.h -std=c++20 -o ml_example

Code for ml_example.cpp:

#include "MessLoggerT.h"


void logBlock(std::string sMode) {
    LOG_STATUS("a normal status message (%s)\n", sMode);
    LOG_WARNING("a normal warning message (%s)\n", sMode);
    LOG_ERROR("a normal error message (%s)\n", sMode);
    LOG_DISP("a normal disp message (%s)\n", sMode);

    LOG_STATUS2("a dual status message (%s)\n", sMode);
    LOG_WARNING2("a dual warning message (%s)\n", sMode);
    LOG_ERROR2("a dual error message (%s)\n", sMode);
    LOG_DISP2("a dual disp message (%s)\n", sMode);

}

int main(int iArgC, char *apArgV[]) {
    int iResult = 0;

    MessLogger::create("glubber.log");
    MessLogger::usePrefix(false);
    MessLogger::useColors(false);

    logBlock("prefix:off, color:off");
    MessLogger::useColors(true);
    logBlock("prefix:off, color:on");
    MessLogger::usePrefix(true);
    logBlock("prefix:on, color_on");
    MessLogger::useColors(false);
    logBlock("prefix:on, color:off");
    MessLogger::usePrefix(false);
    logBlock("prefix:off, color:off");

    xha_printf("so far:\n");
    xha_printf("  %d status messages\n",  MessLogger::getNumStatus());
    xha_printf("  %d warning messages\n", MessLogger::getNumWarning());
    xha_printf("  %d error messages\n",   MessLogger::getNumError());
    xha_printf("  %d disp messages\n",    MessLogger::getNumDisp());

    xha_printf("\n");
    xha_printf("The contents of the log file so far\n");

    // we must set prefixes so that the display function recognizes the message type (if it exists)
    MessLogger::usePrefix(true);
    MessLogger::showLog(MessLogger::SHOW_WARNING | MessLogger::SHOW_ERROR);

    MessLogger::free();
    xha_printf("just checking...\n");
    return iResult;
}