sparse_checkout.sh

#!/bin/bash

# Run this script in the main Trilinos repo dir to do a sparse
# checkout of directories.  For example:
#
#   $ cd Trilinos
#   $ ./sparse_checkout.sh doc/ packages/
#   $ ls
#
# should return just 'sparse_checkout.sh',
# cmake/tribits/common_tools/git/sparse_checkout', 'doc' and 'packages'.
#
# After a sparse checkout, commands like 'git status' will run as fast
# as the size of the remaining checkout.
#
# A sparse checkout can be undone by calling this script with no arguments as:
#
#   $ cd Trilinos
#   $ ./sparse_checkout.sh
#
# NOTES:
#
# a) Make sure you run this script before you change any files or the 'git
# read-tree ...' command will blow away your changes (a lesson I learned the
# hard way).  In general, commit your work *before* you run this script.
#
# b) Git will keep directories not listed if there are symbolic links
# needed to support files in directories that are listed.
#
# c) Sparse checkout is only supported in git 1.7 and later.
#
# d) Early versions of git 1.7.x require that directory names end with '/'
# such as 'doc/' instead of 'doc'.  Later versions of git do not require the
# trailing '/'.

DIRS_FILES_LIST=$@

SC_FILE=.git/info/sparse-checkout

if [ "$DIRS_FILES_LIST" == "" ] ; then

  echo "Undoing sparse checkout"

  # Get the full tree back
  echo "*" > $SC_FILE
  git config core.sparsecheckout true
  git read-tree --reset -u HEAD

  # Wipe out all traces of sparse checkout support
  rm $SC_FILE
  git config core.sparsecheckout false
 
else

  # Tell Git to allow sparse checkout
  git config core.sparsecheckout true
  
  # Set up the list of dirs/files for sparse checkout to keep
  echo > $SC_FILE
  if [ -e cmake/tribits/common_tools/git/sparse_checkout.sh ] ; then
    echo cmake/tribits/common_tools/git/sparse_checkout.sh >> $SC_FILE
  fi
  if [ -e sparse_checkout.sh ] ; then
    echo sparse_checkout.sh >> $SC_FILE
  fi
  for dir_or_file in $DIRS_FILES_LIST ; do
    echo "File/directory to keep: $dir_or_file";
    echo $dir_or_file >> $SC_FILE
  done
  
  # Tell git to process the list of dirs/files
  git read-tree -m -u HEAD
 
fi