GIT-MERGETOOL(1)                                             Git Manual                                            GIT-MERGETOOL(1)

       git-mergetool - Run merge conflict resolution tools to resolve merge conflicts

       git mergetool [--tool=<tool>] [-y | --[no-]prompt] [<file>...]

       Use git mergetool to run one of several merge utilities to resolve merge conflicts. It is typically run after git merge.

       If one or more <file> parameters are given, the merge tool program will be run to resolve differences on each file (skipping
       those without conflicts). Specifying a directory will include all unresolved files in that path. If no <file> names are
       specified, git mergetool will run the merge tool program on every file with merge conflicts.

       -t <tool>, --tool=<tool>
           Use the merge resolution program specified by <tool>. Valid values include emerge, gvimdiff, kdiff3, meld, vimdiff, and
           tortoisemerge. Run git mergetool --tool-help for the list of valid <tool> settings.

           If a merge resolution program is not specified, git mergetool will use the configuration variable merge.tool. If the
           configuration variable merge.tool is not set, git mergetool will pick a suitable default.

           You can explicitly provide a full path to the tool by setting the configuration variable mergetool.<tool>.path. For
           example, you can configure the absolute path to kdiff3 by setting mergetool.kdiff3.path. Otherwise, git mergetool
           assumes the tool is available in PATH.

           Instead of running one of the known merge tool programs, git mergetool can be customized to run an alternative program
           by specifying the command line to invoke in a configuration variable mergetool.<tool>.cmd.

           When git mergetool is invoked with this tool (either through the -t or --tool option or the merge.tool configuration
           variable) the configured command line will be invoked with $BASE set to the name of a temporary file containing the
           common base for the merge, if available; $LOCAL set to the name of a temporary file containing the contents of the file
           on the current branch; $REMOTE set to the name of a temporary file containing the contents of the file to be merged, and
           $MERGED set to the name of the file to which the merge tool should write the result of the merge resolution.

           If the custom merge tool correctly indicates the success of a merge resolution with its exit code, then the
           configuration variable mergetool.<tool>.trustExitCode can be set to true. Otherwise, git mergetool will prompt the user
           to indicate the success of the resolution after the custom tool has exited.

           Print a list of merge tools that may be used with --tool.

       -y, --no-prompt
           Don’t prompt before each invocation of the merge resolution program. This is the default if the merge resolution program
           is explicitly specified with the --tool option or with the merge.tool configuration variable.

           Prompt before each invocation of the merge resolution program to give the user a chance to skip the path.

       -g, --gui
           When git-mergetool is invoked with the -g or --gui option the default merge tool will be read from the configured
           merge.guitool variable instead of merge.tool. If merge.guitool is not set, we will fallback to the tool configured under

           This overrides a previous -g or --gui setting and reads the default merge tool will be read from the configured
           merge.tool variable.

           Process files in the order specified in the <orderfile>, which has one shell glob pattern per line. This overrides the
           diff.orderFile configuration variable (see git-config(1)). To cancel diff.orderFile, use -O/dev/null.

       Everything below this line in this section is selectively included from the git-config(1) documentation. The content is the
       same as what’s found there:

           Override the path for the given tool. This is useful in case your tool is not in the PATH.

           Specify the command to invoke the specified merge tool. The specified command is evaluated in shell with the following
           variables available: BASE is the name of a temporary file containing the common base of the files to be merged, if
           available; LOCAL is the name of a temporary file containing the contents of the file on the current branch; REMOTE is
           the name of a temporary file containing the contents of the file from the branch being merged; MERGED contains the name
           of the file to which the merge tool should write the results of a successful merge.

           Allows the user to override the global mergetool.hideResolved value for a specific tool. See mergetool.hideResolved for
           the full description.

           For a custom merge command, specify whether the exit code of the merge command can be used to determine whether the
           merge was successful. If this is not set to true then the merge target file timestamp is checked and the merge assumed
           to have been successful if the file has been updated, otherwise the user is prompted to indicate the success of the

           Older versions of meld do not support the --output option. Git will attempt to detect whether meld supports --output by
           inspecting the output of meld --help. Configuring mergetool.meld.hasOutput will make Git skip these checks and use the
           configured value instead. Setting mergetool.meld.hasOutput to true tells Git to unconditionally use the --output option,
           and false avoids using --output.

           When the --auto-merge is given, meld will merge all non-conflicting parts automatically, highlight the conflicting parts
           and wait for user decision. Setting mergetool.meld.useAutoMerge to true tells Git to unconditionally use the
           --auto-merge option with meld. Setting this value to auto makes git detect whether --auto-merge is supported and will
           only use --auto-merge when available. A value of false avoids using --auto-merge altogether, and is the default value.

           The vimdiff backend uses this variable to control how its split windows look like. Applies even if you are using Neovim
           (nvim) or gVim (gvim) as the merge tool. See BACKEND SPECIFIC HINTS section for details.

           During a merge Git will automatically resolve as many conflicts as possible and write the MERGED file containing
           conflict markers around any conflicts that it cannot resolve; LOCAL and REMOTE normally represent the versions of the
           file from before Git’s conflict resolution. This flag causes LOCAL and REMOTE to be overwritten so that only the
           unresolved conflicts are presented to the merge tool. Can be configured per-tool via the mergetool.<tool>.hideResolved
           configuration variable. Defaults to false.

           After performing a merge, the original file with conflict markers can be saved as a file with a .orig extension. If this
           variable is set to false then this file is not preserved. Defaults to true (i.e. keep the backup files).

           When invoking a custom merge tool, Git uses a set of temporary files to pass to the tool. If the tool returns an error
           and this variable is set to true, then these temporary files will be preserved, otherwise they will be removed after the
           tool has exited. Defaults to false.

           Git writes temporary BASE, LOCAL, and REMOTE versions of conflicting files in the worktree by default. Git will attempt
           to use a temporary directory for these files when set true. Defaults to false.

           Prompt before each invocation of the merge resolution program.

       git mergetool creates *.orig backup files while resolving merges. These are safe to remove once a file has been merged and
       its git mergetool session has completed.

       Setting the mergetool.keepBackup configuration variable to false causes git mergetool to automatically remove the backup as
       files are successfully merged.

           When specifying --tool=vimdiff in git mergetool Git will open Vim with a 4 windows layout distributed in the following

               |             |           |              |
               |   LOCAL     |   BASE    |   REMOTE     |
               |             |           |              |
               |                                        |
               |                MERGED                  |
               |                                        |

           LOCAL, BASE and REMOTE are read-only buffers showing the contents of the conflicting file in specific commits ("commit
           you are merging into", "common ancestor commit" and "commit you are merging from" respectively)

           MERGED is a writable buffer where you have to resolve the conflicts (using the other read-only buffers as a reference).
           Once you are done, save and exit Vim as usual (:wq) or, if you want to abort, exit using :cq.

       Layout configuration
           You can change the windows layout used by Vim by setting configuration variable mergetool.vimdiff.layout which accepts a
           string where the following separators have special meaning:

           •   + is used to "open a new tab"

           •   , is used to "open a new vertical split"

           •   / is used to "open a new horizontal split"

           •   @ is used to indicate which is the file containing the final version after solving the conflicts. If not present,
               MERGED will be used by default.

           The precedence of the operators is this one (you can use parentheses to change it):

               `@` > `+` > `/` > `,`

           Let’s see some examples to understand how it works:

           •   layout = "(LOCAL,BASE,REMOTE)/MERGED"

               This is exactly the same as the default layout we have already seen.

               Note that / has precedence over , and thus the parenthesis are not needed in this case. The next layout definition
               is equivalent:

                   layout = "LOCAL,BASE,REMOTE / MERGED"

           •   layout = "LOCAL,MERGED,REMOTE"

               If, for some reason, we are not interested in the BASE buffer.

                   |             |           |              |
                   |             |           |              |
                   |   LOCAL     |   MERGED  |   REMOTE     |
                   |             |           |              |
                   |             |           |              |

           •   layout = "MERGED"

               Only the MERGED buffer will be shown. Note, however, that all the other ones are still loaded in vim, and you can
               access them with the "buffers" command.

                   |                                        |
                   |                                        |
                   |                 MERGED                 |
                   |                                        |
                   |                                        |

           •   layout = "@LOCAL,REMOTE"

               When MERGED is not present in the layout, you must "mark" one of the buffers with an asterisk. That will become the
               buffer you need to edit and save after resolving the conflicts.

                   |                   |                    |
                   |                   |                    |
                   |                   |                    |
                   |     LOCAL         |    REMOTE          |
                   |                   |                    |
                   |                   |                    |
                   |                   |                    |


               Three tabs will open: the first one is a copy of the default layout, while the other two only show the differences
               between (BASE and LOCAL) and (BASE and REMOTE) respectively.

                   | <TAB #1> |  TAB #2  |  TAB #3  |       |
                   |             |           |              |
                   |   LOCAL     |   BASE    |   REMOTE     |
                   |             |           |              |
                   |                                        |
                   |                MERGED                  |
                   |                                        |

                   |  TAB #1  | <TAB #2> |  TAB #3  |       |
                   |                   |                    |
                   |                   |                    |
                   |                   |                    |
                   |     BASE          |    LOCAL           |
                   |                   |                    |
                   |                   |                    |
                   |                   |                    |

                   |  TAB #1  |  TAB #2  | <TAB #3> |       |
                   |                   |                    |
                   |                   |                    |
                   |                   |                    |
                   |     BASE          |    REMOTE          |
                   |                   |                    |
                   |                   |                    |
                   |                   |                    |


               Same as the previous example, but adds a fourth tab with the same information as the first tab, with a different

                   |  TAB #1  |  TAB #2  |  TAB #3  | <TAB #4> |
                   |       LOCAL         |                     |
                   |---------------------|                     |
                   |       BASE          |        MERGED       |
                   |---------------------|                     |
                   |       REMOTE        |                     |

               Note how in the third tab definition we need to use parenthesis to make , have precedence over /.

           Instead of --tool=vimdiff, you can also use one of these other variants:

           •   --tool=gvimdiff, to open gVim instead of Vim.

           •   --tool=nvimdiff, to open Neovim instead of Vim.

           When using these variants, in order to specify a custom layout you will have to set configuration variables
           mergetool.gvimdiff.layout and mergetool.nvimdiff.layout instead of mergetool.vimdiff.layout

           In addition, for backwards compatibility with previous Git versions, you can also append 1, 2 or 3 to either vimdiff or
           any of the variants (ex: vimdiff3, nvimdiff1, etc...) to use a predefined layout. In other words, using
           --tool=[g,n,]vimdiffx is the same as using --tool=[g,n,]vimdiff and setting configuration variable
           mergetool.[g,n,]vimdiff.layout to...

           •   x=1: "@LOCAL, REMOTE"

           •   x=2: "LOCAL, MERGED, REMOTE"

           •   x=3: "MERGED"

           Example: using --tool=gvimdiff2 will open gvim with three columns (LOCAL, MERGED and REMOTE).

       Part of the git(1) suite

Git 2.39.2                                                   04/24/2023                                            GIT-MERGETOOL(1)