gitk:tldr:4a6c8

The command gitk --until="${1-1-2015}" is used to open the graphical interface of Git (gitk) and display the commit history until a specific date.

Here's a breakdown of the command:

• gitk: It launches the Git graphical interface, which is a tool to visualize the commit history and related information.
• --until="${1-1-2015}": The --until flag is used to filter the commit history based on a specific date. In this case, the date is set to "1-1-2015". The ${1-1-2015} part is a bash parameter expansion, which allows you to pass a date as an argument when executing the command. If an argument is provided, it will be used as the date. Otherwise, it will default to "1-1-2015".

So, by executing this command in a Git repository, you will be able to visualize the commit history until the specified date in the Git graphical interface.