Adds git-config-save and git-config-restore

diff --git a/git-config-restore b/git-config-restore
new file mode 120000 (symlink)
index 0000000..f667d2e
--- /dev/null
+++ b/git-config-restore
@@ -0,0 +1 @@
+git-config-save
\ No newline at end of file

diff --git a/git-config-save b/git-config-save
new file mode 100755 (executable)
index 0000000..d7d12e9
--- /dev/null
+++ b/git-config-save
@@ -0,0 +1,137 @@
+#!/bin/bash
+#
+# Save/restore your .git/config files in a central place.
+#
+# When called as "git-config-save" or "git config-save",
+# this scripts traverses a folder looking for all .git/config files
+# and makes backups at ~/.config/gitconfigs.
+#
+# When called as "git-config-restore" or "git config-restore"
+# it does the reverse operation: restores all .git/config
+# files, replacing the current repository .git/config's by the one
+# available from ~/.config/gitconfigs.
+#
+# Use cases:
+#
+#   - You work with the repositories in multiple machines and is
+#     looking for a way to sync not just the content but also the
+#     same repository configuration (user name, remotes, etc).
+#
+#   - You want to delete working copies of repositories but want
+#     to keep each repository configuration for future use. In that
+#     case all you have to do is to clone the repository again and
+#     run this command inside your working copy.
+#
+# You may want to put in a schedule job to process all your stuff regularly.
+#
+# Storage format:
+#
+#   - Use ~/.config/gitconfigs/ as base
+#   - Repository identifier is determined by the first commit ID
+#     (not repo URL or any other volatile information). So this
+#     script may fail if you're doing improbable stuff like rebasing
+#     your repo and removing the initial commit.
+#
+# How it saves an item:
+#
+#   - Find all git configurations
+#   - Make a backup at $BASE/$ID/config.$DATE if config differs
+#   - Save the config at $BASE/ID
+#
+# How it restore an item:
+#
+#   - Copy each config from $BASE/ID, if available and if it differs
+#   - Restore always save a timestamped copy at .git/config.$DATE
+
+# Parameters
+BASENAME="`basename $0`"
+BASE="$HOME/.config/gitconfigs"
+DATE="`date +%Y%m%d%I%M%S`"
+
+# Ensure we have a base and that is minimally safe
+mkdir -p  $BASE
+chmod 700 $BASE
+
+# Save config from a repository
+function git_config_save {
+  # Check if we have a config
+  if [ ! -e ".git/config" ]; then
+    echo "$BASENAME: missing config at `pwd`"
+    return
+  fi
+
+  # Repository ID
+  # https://stackoverflow.com/questions/34874343/how-can-i-uniquely-identify-a-git-repository
+  ID="`git rev-list --parents HEAD | tail -1`"
+
+  # Display ID
+  echo $ID
+
+  # Create config folder
+  mkdir -p $BASE/$ID
+
+  # Make a backup
+  if [ -f "$BASE/$ID/config" ] && ! diff .git/config $BASE/$ID/config; then
+    cp $BASE/$ID/config $BASE/$ID/config.$DATE
+  fi
+
+  # Save
+  cp .git/config $BASE/$ID/config
+}
+
+# Restore config tor a repository
+function git_config_restore {
+  # Check if we have a config
+  if [ ! -e ".git/config" ]; then
+    echo "$BASENAME: missing config at `pwd`"
+    return
+  fi
+
+  # Repository ID
+  # https://stackoverflow.com/questions/34874343/how-can-i-uniquely-identify-a-git-repository
+  ID="`git rev-list --parents HEAD | tail -1`"
+
+  # Display ID
+  echo $ID
+
+  # Create config folder
+  mkdir -p $BASE/$ID
+
+  # Check if we have a saved config
+  if [ ! -f "$BASE/$ID/config" ]; then
+    echo "No config for `pwd`, skipping"
+    return
+  fi
+
+  # Make a backup
+  if ! diff .git/config $BASE/$ID/config; then
+    cp .git/config .git/config.$DATE
+  else
+    echo "Identical configs for `pwd`, skipping"
+    return
+  fi
+
+  # Restore
+  cp $BASE/$ID/config .git/config
+
+  # Tell the user about the backup
+  echo "Backup saved at $pwd/.git/config.$DATE"
+}
+
+# Process everything we can find
+find -type d -name .git | while read repo; do
+  # Get absolute folder
+  PWD="`cd $repo/.. &> /dev/null && pwd`"
+
+  echo -n -e "Processing $PWD...\t"
+
+  (
+  cd $PWD
+
+  if [ "$BASENAME" == "git-config-save" ]; then
+    git_config_save
+  else
+    git_config_restore
+  fi
+  )
+done