sha512sum:tldr:380b6

This command is using the sha512sum command-line tool to check the integrity of a file using SHA-512 cryptographic hash algorithm. Let's break down the command:

• sha512sum: It is the actual command that calculates and displays the SHA-512 checksum of a file.

• --check: This option is used to check the checksums of the provided files. It compares the calculated checksum with the checksum stored inside the file, which should be in the format: <checksum> <filename>.

• --quiet: This option makes the command run silently without any unnecessary output. It suppresses the display of individual checksums while checking multiple files.

• ${filename-sha512}: This is a variable reference that is expected to be replaced with the actual name of the file with its associated SHA-512 checksum. The syntax ${variable-name-default} specifies that if the value of filename is not set or null, the default value sha512 will be used.

To summarize, the command is used to verify the integrity of a file using its associated SHA-512 checksum, suppressing unnecessary output.