Compute or check 160-bit SHA1 checksums to verify file integrity. If the file is not specified, or specified as -, read from standard input.
Read files in binary mode.
Read and check the SHA1 sums in the files (or standard input) and verify that they are consistent. The input must have been generated by an earlier sha1sum command.
Print usage information and exit.
Don’t generate output messages; the exit code indicates success or failure. Used only with --check.
Read files in text mode. The default.
Print version information and exit.
Warn about improperly formatted checksum lines. Used only with --check.