Umber

Logging library for everything in the AQUA ecosystem.

Building

With Bob the Builder installed:

bob test install

Basic usage

To use Umber in your project, include the umber.h header and define UMBER_COMPONENT with the name of the component it's meant to cover:

#include <umber.h>
#define UMBER_COMPONENT "The Fitness Gram™ Pacer Test"

When compiling your program, you can link Umber as such:

cc the-fitness-gram-pacer-test.c -lumber

(Notice the subtle play on words, which is difficult to notice; indeed, "Lumber" refers to processed wood, wood which is also what logs are made of.) The header provides the following macros you can use for various log levels:

Macro	Level	POSIX stream	Description
LOG_FATAL	0	stderr	An error occurred which prevents the component from continuing operation
LOG_ERROR	1	stderr	An error occurred which may impair some of the component's functionality
LOG_WARN	2	stderr	Something is not necessarily wrong, but is a bit unexpected
LOG_SUCCESS	3	stdout	The component executed a large operation successfully
LOG_INFO	4	stdout	The component is doing something
LOG_VERBOSE	5	stdout	Extremely detailed information about what the component is currently doing

These definitions are intentionally left a bit vague; the way you use these macros is mostly up to your own common sense. The logging macros may be called as such:

#include <umber.h>
#define UMBER_COMPONENT "The Fitness Gram™ Pacer Test"

int main(void) {
	LOG_FATAL("Oh the humanity")
	LOG_ERROR("Oh the misery")
	LOG_WARN("Oh the shame")
	LOG_SUCCESS("OHHHHHHHH")
	LOG_INFO("Oh there's my wine toaster")
	LOG_VERBOSE("Oh, a butterfly - by the way, my favourite number is %d", *(volatile int*) 0)

	return 0;
}

The output of this program is the following:

You set the UMBER_LVL environment variable to show more or less log messages (default is 3, here's an example with UMBER_LVL=5 and without the segfault lol):

Component filtering

Using the UMBER_BLACKLIST & UMBER_WHITELIST environment variables, you may filter out specific components to see things a little clearer or ease debugging problems in specific components (#5). These environment variables take in a colon-separated list of components to either whitelist (exclusively show) or blacklist (hide) log entries coming from said components:

UMBER_BLACKLIST=the:fitness program # blacklist components "the" & "fitness", i.e. ignore all log entries coming from those components
UMBER_WHITELIST=gram:pacer program # whitelist components "gram" & "pacer", i.e. only show log entries coming from those components

If both a whitelist and a blacklist are supplied, the blacklist takes precedence:

UMBER_BLACKLIST=test UMBER_WHITELIST=test:tm program # blacklist component "test" only

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