sha1sum:tldr:cb914

This command is used to check the integrity of a file using the SHA-1 algorithm.

Let's break down the command:

• sha1sum: This is the command-line tool used to calculate the SHA-1 hash value of a file.
• --check: This option instructs sha1sum to check the hashes of the files.
• --quiet: This option tells sha1sum to operate in quiet mode, which means it will only print whether the checked files have a correct or incorrect hash, without displaying any other output.
• ${filename-sha1}: This is a placeholder for the desired file that you want to check. The hash value of this file should be stored in a separate file with a ".sha1" extension, which is typically named the same as the original file but with the ".sha1" suffix. For example, if the file is named myfile.txt, the hash file should be myfile.txt.sha1.

In summary, this command will calculate the SHA-1 hash of the specified file and compare it to the hash value stored in the corresponding ".sha1" file. The command will output whether the hash is correct or incorrect, but it will do so quietly without any other information or error messages.