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 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.

This is the default if patchid.verbatim is true.

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

+o 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<orderfile>" 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;

+o 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<orderfile>", thereby making existing
databases storing such "unstable" or historical patch-ids
unusable.

+o 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 2.48.1 2025-01-13 GIT-PATCH-ID(1)