Manual: git-patch-id

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

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

SYNOPSIS
       git patch-id [--stable | --unstable | --verbatim]

DESCRIPTION
       Read a patch from the standard input and compute the patch ID for it.

       A "patch ID" is nothing but a sum of SHA-1 of the file diffs associated with a patch, with 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.

       The main usecase for this command is to look for likely duplicate commits.

       When dealing with git diff-tree --patch 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
       --verbatim
	   Calculate the patch ID of the input as it is given, do not strip any whitespace. Implies --stable
	   and forbids --unstable.

	   This is the default if patchid.verbatim is true.

       --stable
	   Use a "stable" sum of hashes as the patch ID. With this option:

	   •   Reordering file diffs that make up a patch does not affect the ID. In particular, two patches
	       produced by comparing the same two trees with two different settings for -O result
	       in the same patch ID signature, thereby allowing the computed result to be used as a key to
	       index some meta-information about the change between the two trees.

	   •   The result is different from the value produced by Git 1.9 and older or produced when an
	       "unstable" hash (see --unstable below) is configured - even when used on a diff output taken
	       without any use of -O, thereby making existing databases storing such "unstable"
	       or historical patch IDs unusable.

	   •   All whitespace within the patch is ignored and does not affect the ID.

	   This is the default if patchid.stable is set to true.

       --unstable
	   Use an "unstable" hash as the patch ID. With this option, the result produced is compatible with
	   the patch ID value produced by Git 1.9 and older and whitespace is ignored. Users with
	   pre-existing databases storing patch IDs produced by Git 1.9 and older (who do not deal with
	   reordered patches) may want to use this option.

	   This is the default.

GIT
       Part of the git(1) suite

Git 2.53.0					 03/02/2026				     GIT-PATCH-ID(1)