sha1sum

sha1sum is a computer program that calculates and verifies SHA-1 hashes. It is commonly used to verify the integrity of files. It (or a variant) is installed by default in most Unix-like operating systems. Variants include shasum (which permits SHA-1 through SHA-512 hash functions to be selected manually) and sha224sum, sha256sum, sha384sum and sha512sum, which use a specific SHA-2 hash function. Versions for Microsoft Windows also exist.

Contents

Usage

Several source code management systems, including Git, Mercurial, Monotone, and Fossil, use the sha1sum of various types of content (file content, directory trees, ancestry information, etc.) to uniquely identify them.

Example

To create a file with an sha1 hash in it, if one isn't provided execute:

sha1sum filename [filename] ... > SHA1SUM

if you are distributing one file you can append ".sha1" to the filename e.g.:

sha1sum my-zip.tar.gz > my-zip.tar.gz.sha1

To verify the file was downloaded correctly you can execute:

sha1sum -c SHA1SUM
# filename: OK
# filename...: OK

and

sha1sum -c my-zip.tar.gz.sha1
# my-zip.tar.gz: OK

respectively

See also

External links