How can I modify or shorten file names in the data file?

Use the --replace REGEX=STRING option on the command line to rename or shorten file names. Be sure to escape special characters when using a shell:

TexturePacker sheet.tps --replace button=panel --replace .\*/=

This example renames button.png to panel.png, and removes all folder paths from the sprite names!

To save these replacements in a .tps project, either use --save to update the project file from the command line, or edit it manually.