# Git Patch

# Creating a patch

To create a patch, there are two steps.

  1. Make your changes and commit them.
  2. Run git format-patch <commit-reference> to convert all commits since the commit (not including it) into patch files.

For example, if patches should be generated from the latest two commits:

git format-patch HEAD~~

This will create 2 files, one for each commit since HEAD~~, like this:

0001-hello_world.patch
0002-beginning.patch

# Applying patches

We can use git apply some.patch to have the changes from the .patch file applied to your current working directory. They will be unstaged and need to be committed.

To apply a patch as a commit (with its commit message), use

git am some.patch

To apply all patch files to the tree:

git am *.patch

# Syntax

  • git am [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8] [--3way] [--interactive] [--committer-date-is-author-date] [--ignore-date] [--ignore-space-change | --ignore-whitespace] [--whitespace=
  • - git am (--continue | --skip | --abort)

    # Parameters

    Parameter Details
    ( )...
    -s, --signoff Add a Signed-off-by: line to the commit message, using the committer identity of yourself.
    -q, --quiet Be quiet. Only print error messages.
    -u, --utf8 Pass -u flag to git mailinfo. The proposed commit log message taken from the e-mail is re-coded into UTF-8 encoding (configuration variable i18n.commitencoding can be used to specify project’s preferred encoding if it is not UTF-8). You can use --no-utf8 to override this.
    --no-utf8 Pass -n flag to git mailinfo.
    -3, --3way When the patch does not apply cleanly, fall back on 3-way merge if the patch records the identity of blobs it is supposed to apply to and we have those blobs available locally.
    --ignore-date, --ignore-space-change, --ignore-whitespace, --whitespace= These flags are passed to the git apply program that applies the patch.
    --patch-format By default the command will try to detect the patch format automatically. This option allows the user to bypass the automatic detection and specify the patch format that the patch(es) should be interpreted as. Valid formats are mbox, stgit, stgit-series, and hg.
    -i, --interactive Run interactively.
    --committer-date-is-author-date By default the command records the date from the e-mail message as the commit author date, and uses the time of commit creation as the committer date. This allows the user to lie about the committer date by using the same value as the author date.
    --ignore-date By default the command records the date from the e-mail message as the commit author date, and uses the time of commit creation as the committer date. This allows the user to lie about the author date by using the same value as the committer date.
    --skip Skip the current patch. This is only meaningful when restarting an aborted patch.
    -S[], --gpg-sign[=] GPG-sign commits.
    --continue, -r, --resolved After a patch failure (e.g. attempting to apply conflicting patch), the user has applied it by hand and the index file stores the result of the application. Make a commit using the authorship and commit log extracted from the e-mail message and the current index file, and continue.
    --resolvemsg= When a patch failure occurs, <msg> will be printed to the screen before exiting. This overrides the standard message informing you to use --continue or --skip to handle the failure. This is solely for internal use between git rebase and git am.
    --abort Restore the original branch and abort the patching operation.