In VMS one may tell the file system to write junk over the existing contents of a file when it is deleted. Here is the DCL command to identify the file for this kind of treatment:
$ SET FILE/ERASE_ON_DELETE SAMPLE.TXT
This allows the policy to be set at one point in time then later users of the file do not have to handle that detail of security. A standard delete which takes the file name out of the directory and frees the space for another file to use will also modify the existing contents to prevent the next user from reading it. The normal delete:
$ DELETE SAMPLE.TXT.*
What is Linux for this?