git-ignore.d

git-ignore.d

#!/bin/bash
# vim: ft=sh

###########################################################################
# Copyright (c) 2011, Nicolas Pouillard
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#
#     * 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.
#
#     * Neither the name of the copyright holders nor the names of other
#       contributors may be used to endorse or promote products derived
#       from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
# OWNER 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.
###########################################################################

###########################################################################
## DOCUMENTATION
##
## git-ignore.d let's you split your .gitignore file into
## multiple files that are put in the .gitignore.d/ directory.
##
## Limitations:
##   * You can no longer use the .gitignore file since it will be
##     generated by git-ignore.d.
##   * You have to call git-ignore.d to refresh the .gitignore
##     file using the files from the .gitignore.d/ directory.
##     We can deal with this limitation by calling git-ignore.d
##     in various git hooks.
##
## Usage:
##   # Make a .gitignore.d/ directory
##   $ mkdir .gitignore.d
##
##   # Move your .gitignore file into it.
##   $ git mv .gitignore .gitignore.d/main
##
##   # You can split .gitignore.d/main into multiple files.
##   $ edit .gitignore.d/*
##
##   # Run git-ignore.d to generate the .gitignore file
##   $ git-ignore.d
##
##   # The generated .gitignore file is actually a symlink to
##   # .git/info/git-ignore.d-exclude so it is safe and cheap
##   # to store the symlink.
##   $ git add .gitignore
##
##   # Commit
##   $ git commit -m 'Switch to .gitignore.d'
##
## Use cases:
##   * It may be just cleaner to have separate files for
##     different sets of rules.
##   * Parts of you ignore rules are generated, thus it is
##     simpler to generate files in .gitignore.d/ instead of
##     `patching' .gitignore.
##   * You want to share common .gitignore rules among several
##     repositories or directories. Symbolic links in the
##     .gitignore.d/ directory is one solution.
###########################################################################

case "$1" in
  "") ;;
  -h|--help|-?)
    grep '^##\( \|$\)' "$0" | sed -e 's/^## \?//'
    exit 0;;
  *)
    echo "Unrecognized argument: use --help to get some help"
    exit 1;;
esac

cd "$(git rev-parse --git-dir)/.."
die(){
  echo error: "$@" >>/dev/stderr
  exit 1
}
if [ "$(git rev-parse --is-inside-work-tree)" = false ]; then
  die "Could not go in the git work-tree."
fi
EXCL=.git/info/git-ignore.d-exclude
rm -f $EXCL
echo "# Generated by git-ignore.d do not edit by hand." >$EXCL
if [ -d .gitignore.d ]; then
  cat .gitignore.d/* >>$EXCL
else
  echo "# No .gitignore.d/ directory." >>$EXCL
fi
chmod -w $EXCL
if [ -e .gitignore ]; then
  if [ "$(readlink .gitignore)" != $EXCL ]; then
    die "git-ignore.d expects to control .gitignore." \
        "You can use any file in .gitignore.d/ instead."
  fi
else
  echo "Making .gitignore a symlink to $EXCL..." >>/dev/stderr
  ln -s $EXCL .gitignore
fi