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

NAME         top

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

SYNOPSIS         top

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

DESCRIPTION         top

       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 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         top

           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<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

           ·   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

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

           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. 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         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control system)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual page,
       see ⟨⟩.  This page was obtained from the
       project's upstream Git repository ⟨⟩ on
       2018-10-29.  (At that time, the date of the most recent commit that
       was found in the repository was 2018-10-26.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

Git           09/04/2017                  GIT-PATCH-ID(1)

Pages that refer to this page: git(1)git-cherry(1)