Day 5: Look ma, no 'argument list too long'! (App::rmhere)
About the series: perlancar's 2014 Advent Calendar: Introduction to a selection of 24 modules which I published in 2014. Table of contents.
If you spend enough time on a Unix/Linux shell, sooner or later you'll be faced with the task of removing files in a directory that contains a lot of those files (in my case, it's usually a Maildir with lots of spam/unread emails). The directory will contain so many files (like 50k or even millions) that doing rm * will fail with the annoying "Argument list too long" message because the * wildcard is expanded by the shell into a multimegabyte list that doesn't fit into the readline buffer. To delete the contents of this directory you will have to resort to some tricks, like using xargs -n, or going up one level, deleting the container directory, and later recreating it.
So I wrote rmhere (distributed in App-rmhere). There are admittedly other faster and smaller scripts for this task (rmhere uses the Perinci::CmdLine CLI framework and thus have a bunch of dependencies). However, my decision to use the framework is because of its progress report feature. Because that's the other thing you will find when deleting files in a big directory: it will take a loong time. rmhere -P will display a nice progress bar on your terminal.
By default rmhere will delete all files in a directory. To prevent silly accidents, if you don't specify the -f (force) option, it will prompt confirmation for each file. Most of the time you'll want rmhere -fP (or with an extra -R to do recursive deletion).