# git-sh-setup

## NAME



           git-sh-setup - Common Git shell script setup code
    


## SYNOPSIS



           _. "$(git --exec-path)/git-sh-setup"_
    


## DESCRIPTION



           This is not a command the end user would want to run. Ever. This
           documentation is meant for people who are studying the
           Porcelain-ish scripts and/or are writing new ones.
    
           The _git sh-setup_ scriptlet is designed to be sourced (using .) by
           other shell scripts to set up some variables pointing at the
           normal Git directories and a few helper shell functions.
    
           Before sourcing it, your script should set up a few variables;
           **USAGE**(and **LONG_USAGE** , if any) is used to define the message given
           by **usage**() shell function. **SUBDIRECTORY_OK** can be set if the
           script can run from a subdirectory of the working tree (some
           commands do not).
    
           The scriptlet sets **GIT_DIR** and **GIT_OBJECT_DIRECTORY** shell
           variables, but does **not** export them to the environment.
    


## FUNCTIONS



           die
               exit after emitting the supplied error message to the standard
               error stream.
    
           usage
               die with the usage message.
    
           set_reflog_action
               Set **GIT_REFLOG_ACTION** environment to a given string (typically
               the name of the program) unless it is already set. Whenever
               the script runs a **git** command that updates refs, a reflog
               entry is created using the value of this string to leave the
               record of what command updated the ref.
    
           git_editor
               runs an editor of user’s choice (GIT_EDITOR, core.editor,
               VISUAL or EDITOR) on a given file, but error out if no editor
               is specified and the terminal is dumb.
    
           is_bare_repository
               outputs **true** or **false** to the standard output stream to
               indicate if the repository is a bare repository (i.e. without
               an associated working tree).
    
           cd_to_toplevel
               runs chdir to the toplevel of the working tree.
    
           require_work_tree
               checks if the current directory is within the working tree of
               the repository, and otherwise dies.
    
           require_work_tree_exists
               checks if the working tree associated with the repository
               exists, and otherwise dies. Often done before calling
               cd_to_toplevel, which is impossible to do if there is no
               working tree.
    
           require_clean_work_tree <action> [<hint>]
               checks that the working tree and index associated with the
               repository have no uncommitted changes to tracked files.
               Otherwise it emits an error message of the form **Cannot**
               _< action>_**:**_< reason>_.  _< hint>_, and dies. Example:
    
                   require_clean_work_tree rebase "Please commit or stash them."
    
           get_author_ident_from_commit
               outputs code for use with eval to set the GIT_AUTHOR_NAME,
               GIT_AUTHOR_EMAIL and GIT_AUTHOR_DATE variables for a given
               commit.
    
           create_virtual_base
               modifies the first file so only lines in common with the
               second file remain. If there is insufficient common material,
               then the first file is left empty. The result is suitable as a
               virtual base input for a 3-way merge.
    


## GIT



           Part of the git(1) suite
    


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