How to get rid of unneeded files on Linux

Using the rmdir command

The rmdir command will remove a directory, but only if it’s empty. To remove the directory and its contents, you need to use a recursive command like that shown below.

Recursive rm

The rm command can be used with an option that allows you to remove an entire directory with a single command. This assumes, of course, that the files are all yours. The rm -r command will run through a directory, remove its contents, and then remove the directory itself.

Using the shred command

Removing a file from a directory does not wipe its contents from the disk even thought the file will no longer be visible or available. That disk space will in time likely be overwritten with other data. However, if you’re removing a file that contains sensitive information, it’s a good idea to use the shred command prior to removing it. That way, the content will have been left in an unrecoverable form.

Using >

Using a command like > myfile will empty a file without removing it from the system. You will then be able to fill it with new content. The cat /dev/null > myfile command will do the same thing, but using just > is easier.

You can also use > to add the output from a command to a file. This will overwrite any prior contents, so use >> if you want to add to the file instead.

$ > oldfile
$ date >> oldfile

Using unlink

The unlink command will only remove a single file. Unlinked files cannot be fully recovered. This command accepts two options, but only –help and –version. Both are outlined in the man page.