git-editor

#!/bin/sh
#
# git-editor - invokes the editor that Git would pick
#
# How to set up:
#     $ install -m 755 git-editor ~/bin/
#     $ git config --global alias.editor '!$HOME/bin/git-editor'
#
# Copyright (c) 2009 Akinori MUSHA
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

: ${GIT_EDITOR:="$(git config core.editor)"}
: ${GIT_EDITOR:="${VISUAL}"}
: ${GIT_EDITOR:="${EDITOR}"}

if [ -z "$GIT_EDITOR" ]; then
    case "$TERM" in
        dumb|'')
	    echo "$0: Terminal is dumb but no VISUAL nor EDITOR defined." >&2
            exit 1
            ;;
        *)
            GIT_EDITOR=vi
            ;;
    esac
fi

case "$GIT_EDITOR" in
    *["\$ 	'"]*)
        exec /bin/sh -c "$GIT_EDITOR \"\$@\"" . "$@"
        ;;
    *)
        exec "$GIT_EDITOR" "$@"
        ;;
esac