tldr/pages/common/sha1sum.md

# sha1sum

> Calculate SHA1 cryptographic checksums.
> More information: <https://www.gnu.org/software/coreutils/sha1sum>.

- Calculate the SHA1 checksum for a file:

`sha1sum {{path/to/file}}`

- Calculate SHA1 checksums for multiple files:

`sha1sum {{path/to/file1}} {{path/to/file2}}`

- Calculate and save the list of SHA1 checksums to a file:

`sha1sum {{path/to/file1}} {{path/to/file2}} > {{path/to/file.sha1}}`

- Read a file of SHA1 sums and verify all files have matching checksums:

`sha1sum --check {{path/to/file.sha1}}`

- Only show a message for missing files or when verification fails:

`sha1sum --check --quiet {{path/to/file.sha1}}`

- Only show a message for files for which verification fails, ignoring missing files:

`sha1sum --ignore-missing --check --quiet {{path/to/file.sha1}}`