srm removes each specified file by overwriting, renaming, and truncating it before unlinking. This prevents other people from undeleting or recovering any information about the file from the command line. By default srm uses 35 passes to overwrite the file's contents. If this seems overkill you can use use the --dod, --doe, --openbsd, --simple option which use less passes. If you specify more than one option (of those listed above) they are executed in the order shown above.
You can use srm to overwrite block devices. The device node is not removed after overwriting. This feature is available on Linux. Files with multiple hard links will be unlinked but not overwritten.
srm, like every program that uses the getopt function to parse its arguments, lets you use the -- option to indicate that all following arguments are non-options. To remove a file called `-f' in the current directory, you could type either
-r, -R, --recursive
srm can write to block devices on Linux. You can use srm to securely delete an entire hard disk, however you should only do this for classic magnetic drives. The modern solid state disks (SSD) have a faster and better way to erase all contents, Secure Erase. For a Linux operating system see https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase
srm can not remove write protected files owned by another user, regardless of the permissions on the directory containing the file.
Development and discussion of srm is carried out at https://sourceforge.net/projects/srm/ which is also accessible via http://srm.sourceforge.net/. See http://en.wikipedia.org/wiki/Data_remanence for a general discussion about overwriting data.
|Matt Gauthier, Dirk Jagdmann||1.2.12||srm(1)|