flog

flog is a command-line tool for sending log messages to Apple's unified logging system and is primaily intended for use in scripts.

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Getting started

Installation

Install with Homebrew:

brew install marcransome/tap/flog

Logging messages

To log a message using the default log level:

flog '<message>'

Optionally specify a subsystem and category using the -s|--subsystem and -c|--category options:

flog -s uk.co.fidgetbox -c general 'informational message'

Override the default log level using the -l|--level option and one of the values info, debug, error or fault:

flog -l fault -s uk.co.fidgetbox -c general 'unrecoverable failure'

Warning: Log message strings are public by default and can be read using the log(1) command or Console app. To mark a message as private add the -p|--private option to the command. Doing so will redact the message string, which will be shown as '<private>' when accessed using the methods previously mentioned. Device Management Profiles can be used to grant access to private log messages.

Reading log messages

Refer to the log(1) man page provided on macOS-based systems for extensive documentation on how to access system wide log messages, or alternatively use the Console app.

Here's an example log stream in Console, filtered by subsystem name, showing messages generated by flog:

And here's a similar log stream viewed with Apple's log(1) command:

Building

Requirements

• macOS (11.x or later)
• A C17 compiler
• CMake (3.22 or later)

Building from source

To perform an out-of-source build from the project directory:

cmake -S . -B build
cmake --build build

Acknowledgements

• Trunk icon made by Freepik from www.flaticon.com

License

flog is provided under the terms of the MIT License.

Contact

Email me at [email protected] or tweet @marcransome.