.common/setup

common-setup.sh

#!/bin/bash

COMMON=.common

if [ ! -d "$HOME/$COMMON" ]; then
   if ! which git >/dev/null 2>&1; then
      if which apt-get >/dev/null 2>&1 && which sudo >/dev/null 2>&1; then
         if ! sudo apt-get install git-core; then
            echo "Failed to install git; can't check out files" >&2
            exit 1
         fi
      else
         echo "Don't know how to install git; can't check out files" >&2
         exit 1
      fi
   fi

   echo "Checking out config files... this will probably only work if you have"
   echo "an SSH key available via key forwarding or something."

   if ! git clone gitosis@sierra.trebex.net:config.git "$HOME/$COMMON"; then
      echo "Failed to check out files" >&2
      exit 1
   fi
fi

cd "$HOME/$COMMON"

if readlink -e . >/dev/null 2>&1; then
   normpath() {
      readlink -e "$1"
   }
else
   normpath() {
      python -c 'import sys; import os.path; print os.path.normpath(sys.argv[1])' "$1"
   }
fi

dolink() {
   cmn="$COMMON"
   base="$2"
   until [ "$(dirname "$base")" = . ]; do
      base="$(dirname "$base")"
      cmn="../$cmn"
   done
   target="$cmn/$1"

   if [ ! -e "$HOME/$COMMON/$1" ]; then
      echo "Can't find link target '$COMMON/$1'"
      return
   fi

   if [ ! -d "$HOME/$(dirname "$2")" ]; then
      mkdir -p "$HOME/$(dirname "$2")"
   fi

   if [ -L "$HOME/$2" ]; then
      curr="$(normpath "$HOME/$2")"
      xtarget="$(normpath "$HOME/$COMMON/$1")"

      if [ "$curr" = "$xtarget" ]; then
         return
      fi

      echo "# '~/$2' currently links to '$curr'"
   fi

   if [ ! -e "$HOME/$2" ]; then
      echo ln -s "$target" "$HOME/$2"
   elif [ -f "$HOME/$2" ] && which diff >/dev/null 2>&1; then
      if diff -q "$HOME/$COMMON/$1" "$HOME/$2" >/dev/null 2>&1; then
         if [ -e "$HOME/$2" ]; then echo mv "$HOME/$2" "$HOME/$2.prev"; fi
         echo ln -s "$target" "$HOME/$2"
      else
         echo "# Files ~/$COMMON/$1 and ~/$2 differ:"
         printf '## diff -u ~/%q ~/%q\n' "$2" "$COMMON/$1"
         printf '## mv ~/%q ~/%q.prev && ln -s %q ~/%q\n' "$2" "$2" "$target" "$2"
      fi
   else
      echo "# Unable to compare ~/$COMMON/$1 and ~/$2; skipping:"
      printf '## mv ~/%q ~/%q.prev && ln -s %q ~/%q\n' "$2" "$2" "$target" "$2"
   fi
}

for i in $(ls -A "$HOME/$COMMON"); do
   case "$i" in
      .|..|.git) : ;;
      .*) dolink "$i" "$i" ;;
   esac
done

dolink "subversion.config" ".subversion/config"
dolink "ssh.authorized_keys" ".ssh/authorized_keys"
dolink "bin.sudo-ssh" "bin/sudo-ssh"
dolink "global.gitignore" ".gitignore"
dolink "gem.credentials" ".gem/credentials"

zshrc

if [ -w ~ -a -d ~/.common/.git ] && which git >/dev/null 2>&1 && [ -n "$SSH_AUTH_SOCK" -o -s ~/.ssh/id_dsa ]; then
  (
    echo ".common: Checking status"
    cd ~/.common

    UNCOMMITTED=""
    if ! git diff --quiet 2>&1 | env grep -q 'usage:'; then
      if ! git diff --quiet; then
        UNCOMMITTED=yes
      fi
    else
      # git-diff is too old for --quiet; git-status will obviously
      # behave as we expect.
      if git status | env grep -q '^#'; then
        UNCOMMITTED=yes
      fi
    fi

    if [ -n "$UNCOMMITTED" ]; then
      echo "Uncommitted changes in .common/"
      git status
      echo
    else
      echo ".common: Checking for outdated fetch"
      DATEARG=.git/FETCH_HEAD
      if ! date -r "$DATEARG" >/dev/null 2>&1; then
        # Nasty: if we don't have 'date -r FILENAME', assume we have a
        # Mac OS X compatible (BSD compatible?) stat on the path. (But
        # avoid the zsh builtin.)
        DATEARG=`env stat -f '%Dm' "$DATEARG"`
      fi

      if [ ! -f .git/FETCH_HEAD ] || [ "$(date -r "$DATEARG" '+%Y%W')" -ne "$(date '+%Y%W')" ]; then
        echo "Pulling config files: "
        git pull
        if [ -x ~/.common/setup ]; then
          ~/.common/setup
        fi
        echo
      fi

      echo ".common: Checking for unpushed changes"
      orig=$(if [ -f .git/refs/remotes/origin/master -o -f .git/remotes/origin/master ]; then
        echo 'origin/master'
      else
        echo 'origin'
      fi)

      if ! git diff --quiet 2>&1 | env grep -q 'usage:'; then
        if ! git diff --quiet "$orig" master ; then
          echo "Changes to .common/ not pushed"
          git diff --stat "$orig" master
          echo
        fi
      else
        if git diff "$orig" master | env grep -q .; then
          echo "Changes to .common/ not pushed"
          git diff --stat "$orig" master
          echo
        fi
      fi
    fi
    echo ".common: All done"
  ) | cat >&2  # 'cat' is so git doesn't see the tty
fi