Linux Command Directory
This directory of Linux commands is from Linux in a Nutshell, 5th Edition.
Click on any of the 687 commands below to get a description and list of available options. All links in the command summaries point to the online version of the book on Safari Bookshelf.
sha1sum [option] [files] sah1sum [option] --check [file]
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. The default on DOS or Windows.
Check the SHA1 sum and file information in the file argument (or standard input) against the corresponding files 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.
Compute the SHA1 sum for the specified string. This option does not take a file argument. Put quotes around the string if it contains spaces.
Read files in text mode. The default.
Print version information and exit.
Warn about improperly formatted checksum lines. Used only with --check.