git-patch-id(1) linux man page | unix.com

GIT-PATCH-ID(1) 						    Git Manual							   GIT-PATCH-ID(1)

NAME
       git-patch-id - Compute unique ID for a patch

SYNOPSIS
       git patch-id < <patch>

DESCRIPTION
       A "patch ID" is nothing but a SHA-1 of the diff associated with a patch, with whitespace and line numbers ignored. As such, it's
       "reasonably stable", but at the same time also reasonably unique, i.e., two patches that have the same "patch ID" are almost guaranteed to
       be the same thing.

       IOW, you can use this thing to look for likely duplicate commits.

       When dealing with git diff-tree output, it takes advantage of the fact that the patch is prefixed with the object name of the commit, and
       outputs two 40-byte hexadecimal strings. The first string is the patch ID, and the second string is the commit ID. This can be used to make
       a mapping from patch ID to commit ID.

OPTIONS
       <patch>
	   The diff to create the ID of.

GIT
       Part of the git(1) suite

Git 1.8.5.3							    01/14/2014							   GIT-PATCH-ID(1)