How to use the command 'srm' (with examples)
The command ‘srm’ is used to securely remove files or directories by overwriting the existing data one or multiple times. It is a drop-in replacement for the ‘rm’ command.
Use case 1: Remove a file after a single-pass overwriting with random data
Code:
srm -s path/to/file
Motivation: This use case is useful when you want to securely delete a file by replacing its contents with random data. It ensures that the original data is completely unrecoverable.
Explanation:
-s: Specifies a single pass of overwriting with random data.path/to/file: The path to the file that needs to be removed.
Example output: The file “path/to/file” will be securely removed from the system after a single pass of overwriting with random data.
Use case 2: Remove a file after seven passes of overwriting with random data
Code:
srm -m path/to/file
Motivation: In some cases, a single pass of overwriting with random data may not be enough to securely remove sensitive files. The motivation for this use case is to provide a higher level of security by performing seven passes of overwriting.
Explanation:
-m: Specifies seven passes of overwriting with random data.path/to/file: The path to the file that needs to be removed.
Example output: The file “path/to/file” will be securely removed from the system after seven passes of overwriting with random data.
Use case 3: Recursively remove a directory and its contents overwriting each file with a single-pass of random data
Code:
srm -r -s path/to/directory
Motivation: Often, you may need to securely delete an entire directory and its contents. This use case provides a convenient way to accomplish that by recursively removing the directory and overwriting each file within it with random data.
Explanation:
-r: Recursively removes the directory and its contents.-s: Specifies a single pass of overwriting with random data.path/to/directory: The path to the directory that needs to be removed.
Example output: The directory “path/to/directory” will be recursively removed, and each file within it will be securely deleted after a single pass of overwriting with random data.
Use case 4: Prompt before every removal
Code:
srm -i *
Motivation: This use case is helpful when you want to avoid accidental deletions. The prompt before every removal ensures that you are prompted to confirm the deletion of each file before it is permanently removed.
Explanation:
-i: Prompts before every removal.*: Specifies that all files in the current directory will be considered for removal.
Example output: The command will prompt you to confirm the removal of each file in the current directory before it is deleted.
Conclusion:
The ‘srm’ command provides a secure way to delete files and directories by overwriting the data with random information. It offers flexibility in terms of the number of passes and provides an option to prompt before every removal. By using the examples provided, you can safely remove sensitive data from your system.
