sw — command-line stopwatch

sw is a command-line stopwatch utility with the ability to create multiple named stopwatches that persist across executions (named timers are saved in a plain-text config file).

Usage

Run an ad-hoc stopwatch

sw

Starts a stopwatch at 0 and updates the display until you stop it (Ctrl+C). The timer is not saved.

Run an existing named timer or create a new named timer

sw my_timer
# or, for a name with spaces,
sw "my timer"

If the timer already exists in the config file, sw resumes it and displays the time elapsed since it was started. If it does not exist, sw creates it and starts it immediately. Names can contain any characters but may not begin with a -. If the name contains a space, the whole name must be enclosed in double quotes. When you exit sw with Ctrl+C, the start time is persisted, so the next run continues from the original start.

List saved timers

sw --list-timers
# or,
sw -l

Delete an existing timer

sw --delete-timer my_timer
# or,
sw -d my_timer

Print usage iunformation

sw --help
# or,
sw -h
# or,
sw -?

Config file

The config file is a plain-text file with repeating pairs of a bracketed name and a numeric timestamp. Example:

[some name]
153818613518

[some other name]
135168412151

• Lines starting with [ and ending with ] indicate a timer name.
• The line immediately following a timer name is an implementation-defined value representing the start time of the timer. Its format and interpretation is not published, subject to change, and values are not intended to be user-editable.
• Config files are not portable across systems. On linux and other unix-like systems the config file location defaults to $XDG_CONFIG_HOME/sw.ini (usually ~/.config/)
• Any operation that causes the config file to be written to, for example, running with -d <timer name> or with a new timer name will cause the entire file to be normalized; invalid entries and unnecessary whitespace will be removed.

Build

This project uses CMake and requires C++23. Googletest is required to build the unit tests (built by default, use -DBUILD_TESTS=OFF to skip building the tests). From the project root run:

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

This produces the sw executable in build/exe and a unit test executable in build/tests.

Other things in this repository

The csharp and rust folders contain partial "experimental" implementations of sw in these languages as an exercise in comparing implementations of the same thing in different languages. They are not really meant to be used.