A simple head-only logging library implemented in cpp , and harbarapink rewrite log.c to a single hpp file which could be used in cpp.

include log.hpp to your project

log_trace(const char *fmt, ...);
log_debug(const char *fmt, ...);
log_info(const char *fmt, ...);
log_warn(const char *fmt, ...);
log_error(const char *fmt, ...);
log_fatal(const char *fmt, ...);

Each function takes a printf format string followed by additional arguments:

log_trace("Hello %s", "world")

Resulting in a line with the given format printed to stderr:

20:18:26 TRACE src/main.c:11: Hello world

Quiet-mode can be enabled by passing true to the log_set_quiet() function. While this mode is enabled the library will not output anything to stderr, but will continue to write to files and callbacks if any are set.

The current logging level can be set by using the log_set_level() function. All logs below the given level will not be written to stderr. By default the level is LOG_TRACE, such that nothing is ignored.

One or more file pointers where the log will be written can be provided to the library by using the log_add_fp() function. The data written to the file output is of the following format:

2047-03-11 20:18:26 TRACE src/main.c:11: Hello world

Any messages below the given level are ignored. If the library failed to add a file pointer a value less-than-zero is returned.

One or more callback functions which are called with the log data can be provided to the library by using the log_add_callback() function. A callback function is passed a log_Event structure containing the line number, filename, fmt string, va printf va_list, level and the given udata.

If the log will be written to from multiple threads a lock function can be set. The function is passed the boolean true if the lock should be acquired or false if the lock should be released and the given udata value.

Returns the name of the given log level as a string.

If the library is compiled with -DLOG_USE_COLOR ANSI color escape codes will be used when printing.

This library is free software; you can redistribute it and/or modify it under the terms of the MIT license. See LICENSE for details.