#!/bin/sh
 
 # This program is licensed under the GNU GPL version 2 or later.
-# (c) Richard "RichiH" Hartmann <richih.mailinglist@gmail.com>, 2011-2013
+# (c) Richard "RichiH" Hartmann <richih@debian.org>, 2011-2014
 # For details, see LICENSE. To submit patches, you have to agree to
 # license your code under the GNU GPL version 2 or later.
 
 # While the following is not legally binding, the author would like to
 # explain the choice of GPLv2+ over GPLv3+.
 # The author prefers GPLv3+ over GPLv2+ but feels it's better to maintain
-# full compability with git. In case git ever changes its licensing terms,
+# full compatibility's with Git. In case Git ever changes its licensing terms,
 # which is admittedly extremely unlikely to the point of being impossible,
 # this software will most likely follow suit.
 
+# This should always be the first line of code to facilitate debugging
+[ -n "$VCSH_DEBUG" ] && set -vx
+
+
+# If '.git-HEAD' is appended to the version, you are seeing an unreleased
+# version of vcsh; the master branch is supposed to be clean at all times
+# so you can most likely just use it nonetheless
+VERSION='1.20141026'
 SELF=$(basename $0)
 
 fatal() {
        echo "$SELF: fatal: $1" >&2
+       [ -z $2 ] && exit 1
        exit $2
 }
 
 # We need to run getops as soon as possible so we catch -d and other
 # options that will modify our behaviour.
 # Commands are handled at the end of this script.
-while getopts  "c:dv" flag; do
-       if [ "$1" = '-d' ] || [ "$1" = '--debug' ]; then
+while getopts "c:dv" flag; do
+       if [ x"$1" = x'-d' ] || [ x"$1" = x'--debug' ]; then
                set -vx
                VCSH_DEBUG=1
-       elif [ "$1" = '-v' ];then
+               echo "debug mode on"
+               echo "$SELF $VERSION"
+       elif [ x"$1" = x'-v' ]; then
                VCSH_VERBOSE=1
-       elif [ "$1" = '-c' ];then
+               echo "verbose mode on"
+               echo "$SELF $VERSION"
+       elif [ x"$1" = x'-c' ]; then
                VCSH_OPTION_CONFIG=$OPTARG
        fi
        shift 1
 
 source_all() {
        # Source file even if it's in $PWD and does not have any slashes in it
-       case "$1" in
+       case $1 in
                */*) . "$1";;
                *)   . "$PWD/$1";;
        esac;
 
 # Read configuration and set defaults if anything's not set
 [ -n "$VCSH_DEBUG" ]                  && set -vx
-[ -z "$XDG_CONFIG_HOME" ]             && XDG_CONFIG_HOME="$HOME/.config"
+: ${XDG_CONFIG_HOME:="$HOME/.config"}
 
 # Read configuration files if there are any
 [ -r "/etc/vcsh/config" ]             && . "/etc/vcsh/config"
 [ -n "$VCSH_DEBUG" ]                  && set -vx
 
 # Read defaults
-[ -z "$VCSH_REPO_D" ]                 && VCSH_REPO_D="$XDG_CONFIG_HOME/vcsh/repo.d"
-[ -z "$VCSH_HOOK_D" ]                 && VCSH_HOOK_D="$XDG_CONFIG_HOME/vcsh/hooks-enabled"
-[ -z "$VCSH_BASE" ]                   && VCSH_BASE="$HOME"
-[ -z "$VCSH_GITIGNORE" ]              && VCSH_GITIGNORE='exact'
+: ${VCSH_REPO_D:="$XDG_CONFIG_HOME/vcsh/repo.d"}
+: ${VCSH_HOOK_D:="$XDG_CONFIG_HOME/vcsh/hooks-enabled"}
+: ${VCSH_OVERLAY_D:="$XDG_CONFIG_HOME/vcsh/overlays-enabled"}
+: ${VCSH_BASE:="$HOME"}
+: ${VCSH_GITIGNORE:=exact}
+: ${VCSH_GITATTRIBUTES:=none}
+: ${VCSH_WORKTREE:=absolute}
+
+if [ ! "x$VCSH_GITIGNORE" = 'xexact' ] && [ ! "x$VCSH_GITIGNORE" = 'xnone' ] && [ ! "x$VCSH_GITIGNORE" = 'xrecursive' ]; then
+       fatal "'\$VCSH_GITIGNORE' must equal 'exact', 'none', or 'recursive'" 1
+fi
+
+if [ ! "x$VCSH_WORKTREE" = 'xabsolute' ] && [ ! "x$VCSH_WORKTREE" = 'xrelative' ]; then
+       fatal "'\$VCSH_WORKTREE' must equal 'absolute', or 'relative'" 1
+fi
 
 
 help() {
    -v                   Enable verbose mode
 
    commands:
-   clone <remote> \\
+   clone [-b <branch>] \\
+         <remote> \\
          [<repo>]       Clone from an existing repository
+   commit               Commit in all repositories
    delete <repo>        Delete an existing repository
    enter <repo>         Enter repository; spawn new instance of \$SHELL
    help                 Display this help text
    init <repo>          Initialize a new repository
    list                 List all repositories
-   list-tracked         List all files tracked by vcsh
-   list-tracked-by \\
-        <repo>          List files tracked by a repository
+   list-tracked \\
+        [<repo>]        List all files tracked all or one repositories
+   list-untracked \\
+        [<-r>] [<repo>] List all files not tracked by all or one repositories
+   pull                 Pull from all vcsh remotes
+   push                 Push to vcsh remotes
    rename <repo> \\
           <newname>     Rename repository
    run <repo> \\
        <command>        Use this repository
-   setup <repo>         Set up repository with recommended settings
+   status [<repo>]      Show statuses of all/one vcsh repositories
+   upgrade <repo>       Upgrade repository to currently recommended settings
+   version              Print version information
    which <substring>    Find substring in name of any tracked file
    write-gitignore \\
    <repo>               Write .gitignore.d/<repo> via git ls-files
 }
 
 clone() {
+       hook pre-clone
        init
        git remote add origin "$GIT_REMOTE"
-       git config branch.master.remote origin
-       git config branch.master.merge  refs/heads/master
-       if [ $(git ls-remote origin master 2> /dev/null | wc -l ) -lt 1 ]; then
-               info "remote is empty, not merging anything"
+       git checkout -b "$VCSH_BRANCH" || return $?
+       git config branch."$VCSH_BRANCH".remote origin
+       git config branch."$VCSH_BRANCH".merge  refs/heads/"$VCSH_BRANCH"
+       if [ $(git ls-remote origin "$VCSH_BRANCH" 2> /dev/null | wc -l ) -lt 1 ]; then
+               info "remote is empty, not merging anything.
+  You should add files to your new repository."
                exit
        fi
-       git fetch
-       for object in $(git ls-tree -r origin/master | awk '{print $4}'); do
+       git fetch origin "$VCSH_BRANCH"
+       hook pre-merge
+       git ls-tree -r --name-only origin/"$VCSH_BRANCH" | (while read object; do
                [ -e "$object" ] &&
                        error "'$object' exists." &&
-                       VCSH_CONFLICT=1;
+                       VCSH_CONFLICT=1
        done
-       [ "$VCSH_CONFLICT" = '1' ] &&
+       [ x"$VCSH_CONFLICT" = x'1' ]) &&
                fatal "will stop after fetching and not try to merge!
-  Once this situation has been resolved, run 'vcsh run $VCSH_REPO_NAME git pull' to finish cloning.\n" 17
-       git merge origin/master
+  Once this situation has been resolved, run 'vcsh $VCSH_REPO_NAME pull' to finish cloning." 17
+       git merge origin/"$VCSH_BRANCH"
+       hook post-merge
+       hook post-clone
+       retire
+       hook post-clone-retired
+}
+
+commit() {
+       hook pre-commit
+       for VCSH_REPO_NAME in $(list); do
+               echo "$VCSH_REPO_NAME: "
+               GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+               use
+               git commit --untracked-files=no --quiet
+               VCSH_COMMAND_RETURN_CODE=$?
+               echo
+       done
+       hook post-commit
 }
 
 delete() {
 }
 
 hook() {
-       for hook in $VCSH_HOOK_D/$1* $VCSH_HOOK_D/$VCSH_REPO_NAME.$1*; do
+       for hook in "$VCSH_HOOK_D/$1"* "$VCSH_HOOK_D/$VCSH_REPO_NAME.$1"*; do
                [ -x "$hook" ] || continue
-               info "executing '$hook'"
+               verbose "executing '$hook'"
                "$hook"
        done
 }
 
 init() {
+       hook pre-init
        [ ! -e "$GIT_DIR" ] || fatal "'$GIT_DIR' exists" 10
-       export GIT_WORK_TREE="$VCSH_BASE"
-       mkdir -p "$GIT_WORK_TREE" || fatal "could not create '$GIT_WORK_TREE'" 50
-       cd "$GIT_WORK_TREE" || fatal "could not enter '$GIT_WORK_TREE'" 11
-       git init
-       setup
+       mkdir -p "$VCSH_BASE" || fatal "could not create '$VCSH_BASE'" 50
+       cd "$VCSH_BASE" || fatal "could not enter '$VCSH_BASE'" 11
+       git init --shared=0600
+       upgrade
+       hook post-init
 }
 
 list() {
        for repo in "$VCSH_REPO_D"/*.git; do
-               [ -d "$repo" ] && [ -r "$repo" ] && echo $(basename "$repo" .git)
+               [ -d "$repo" ] && [ -r "$repo" ] && echo "$(basename "$repo" .git)"
        done
 }
 
 get_files() {
-       export GIT_DIR="$VCSH_REPO_D/$VCSH_REPO_NAME.git"
+       GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
        git ls-files
 }
 
 list_tracked() {
-       for VCSH_REPO_NAME in $(list); do
-               get_files
-       done | sort -u
+       VCSH_REPO_NAME=$2; export VCSH_REPO_NAME
+       if [ -n "$VCSH_REPO_NAME" ]; then
+               get_files | list_tracked_helper
+       else
+               for VCSH_REPO_NAME in $(list); do
+                       get_files
+               done | list_tracked_helper
+       fi
+}
+
+list_tracked_helper() {
+       sed "s,^,$(printf '%s\n' "$VCSH_BASE/" | sed 's/[,\&]/\\&/g')," | sort -u
 }
 
 list_tracked_by() {
-       use
-       git ls-files | sort -u
+       list_tracked $2
+}
+
+list_untracked() {
+       command -v 'comm' >/dev/null 2>&1 || fatal "Could not find 'comm'"
+
+       temp_file_others=$(mktemp "${TMPDIR:-/tmp}/tmp.XXXXXXXXXX") || fatal 'Could not create temp file'
+       temp_file_untracked=$(mktemp "${TMPDIR:-/tmp}/tmp.XXXXXXXXXX") || fatal 'Could not create temp file'
+       temp_file_untracked_copy=$(mktemp "${TMPDIR:-/tmp}/tmp.XXXXXXXXXX") || fatal 'Could not create temp file'
+
+       # Hack in support for `vcsh list-untracked -r`...
+       directory_opt="--directory"
+       shift 1
+       while getopts "r" flag; do
+               if [ x"$1" = x'-r' ]; then
+                       unset directory_opt
+               fi
+               shift 1
+       done
+       # ...and parse for a potential parameter afterwards. As we shifted things out of $* in during getops, we need to look at $1
+       VCSH_REPO_NAME=$1; export VCSH_REPO_NAME
+
+       if [ -n "$VCSH_REPO_NAME" ]; then
+               list_untracked_helper $VCSH_REPO_NAME
+       else
+               for VCSH_REPO_NAME in $(list); do
+                       list_untracked_helper $VCSH_REPO_NAME
+               done
+       fi
+       cat $temp_file_untracked
+
+       unset directory_opt directory_component
+       rm -f $temp_file_others $temp_file_untracked $temp_file_untracked_copy || fatal 'Could not delete temp files'
+}
+
+list_untracked_helper() {
+       export GIT_DIR="$VCSH_REPO_D/$VCSH_REPO_NAME.git"
+       git ls-files --others "$directory_opt" | (
+               while read line; do
+                       echo "$line"
+                       directory_component=${line%%/*}
+                       [ -d "$directory_component" ] && printf '%s/\n' "$directory_component"
+               done
+               ) | sort -u > $temp_file_others
+       if [ -z "$ran_once" ]; then
+               ran_once=1
+               cp $temp_file_others $temp_file_untracked || fatal 'Could not copy temp file'
+       fi
+       cp $temp_file_untracked $temp_file_untracked_copy || fatal 'Could not copy temp file'
+       comm -12 --nocheck-order $temp_file_others $temp_file_untracked_copy > $temp_file_untracked
+}
+
+pull() {
+       hook pre-pull
+       for VCSH_REPO_NAME in $(list); do
+               printf '%s: ' "$VCSH_REPO_NAME"
+               GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+               use
+               git pull
+               VCSH_COMMAND_RETURN_CODE=$?
+               echo
+       done
+       hook post-pull
+}
+
+push() {
+       hook pre-push
+       for VCSH_REPO_NAME in $(list); do
+               printf '%s: ' "$VCSH_REPO_NAME"
+               GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+               use
+               git push
+               VCSH_COMMAND_RETURN_CODE=$?
+               echo
+       done
+       hook post-push
+}
+
+retire() {
+       unset VCSH_DIRECTORY
 }
 
 rename() {
        [ -d "$GIT_DIR_NEW" ] && fatal "'$GIT_DIR_NEW' exists" 54
        mv -f "$GIT_DIR" "$GIT_DIR_NEW" || fatal "Could not mv '$GIT_DIR' '$GIT_DIR_NEW'" 52
 
+       # Now that the repository has been renamed, we need to fix up its configuration
+       # Overwrite old name..
+       GIT_DIR=$GIT_DIR_NEW
+       VCSH_REPO_NAME=$VCSH_REPO_NAME_NEW
+       # ..and clobber all old configuration
+       upgrade
 }
 
 run() {
        hook pre-run
        use
-       $VCSH_EXTERNAL_COMMAND
+       "$@"
+       VCSH_COMMAND_RETURN_CODE=$?
        hook post-run
 }
 
-setup() {
-       hook pre-setup
+status() {
+       if [ -n "$VCSH_REPO_NAME" ]; then
+               status_helper $VCSH_REPO_NAME
+       else
+               for VCSH_REPO_NAME in $(list); do
+                       echo "$VCSH_REPO_NAME:"
+                       status_helper $VCSH_REPO_NAME
+                       echo
+               done
+       fi
+}
+
+status_helper() {
+       GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+       use
+       remote_tracking_branch=$(git rev-parse --abbrev-ref --symbolic-full-name @{u} 2> /dev/null) && {
+               commits_behind=$(git log ..${remote_tracking_branch} --oneline | wc -l)
+               commits_ahead=$(git log ${remote_tracking_branch}.. --oneline | wc -l)
+               [ ${commits_behind} -ne 0 ] && echo "Behind $remote_tracking_branch by $commits_behind commits"
+               [ ${commits_ahead} -ne 0 ] && echo "Ahead of $remote_tracking_branch by $commits_ahead commits"
+       }
+       git status --short --untracked-files='no'
+       VCSH_COMMAND_RETURN_CODE=$?
+}
+
+upgrade() {
+       hook pre-upgrade
+       # fake-bare repositories are not bare, actually. Set this to false
+       # because otherwise Git complains "fatal: core.bare and core.worktree
+       # do not make sense"
+       git config core.bare false
+       # core.worktree may be absolute or relative to $GIT_DIR, depending on
+       # user preference
+       if [ ! "x$VCSH_WORKTREE" = 'xabsolute' ]; then
+               git config core.worktree "$(cd "$GIT_DIR" && GIT_WORK_TREE=$VCSH_BASE git rev-parse --show-cdup)"
+       elif [ ! "x$VCSH_WORKTREE" = 'xrelative' ]; then
+               git config core.worktree "$VCSH_BASE"
+       fi
+       [ ! "x$VCSH_GITIGNORE" = 'xnone' ] && git config core.excludesfile ".gitignore.d/$VCSH_REPO_NAME"
+       [ ! "x$VCSH_GITATTRIBUTES" = 'xnone' ] && git config core.attributesfile ".gitattributes.d/$VCSH_REPO_NAME"
+       git config vcsh.vcsh 'true'
        use
-       git config core.worktree     "$GIT_WORK_TREE"
-       git config core.excludesfile ".gitignore.d/$VCSH_REPO_NAME"
-       git config vcsh.vcsh         'true'
        [ -e "$VCSH_BASE/.gitignore.d/$VCSH_REPO_NAME" ] && git add -f "$VCSH_BASE/.gitignore.d/$VCSH_REPO_NAME"
-       hook post-setup
+       [ -e "$VCSH_BASE/.gitattributes.d/$VCSH_REPO_NAME" ] && git add -f "$VCSH_BASE/.gitattributes.d/$VCSH_REPO_NAME"
+       hook post-upgrade
 }
 
 use() {
        git_dir_exists
-       export GIT_WORK_TREE="$(git config --get core.worktree)"
-       export VCSH_DIRECTORY="$VCSH_REPO_NAME"
+       VCSH_DIRECTORY=$VCSH_REPO_NAME; export VCSH_DIRECTORY
 }
 
 which() {
+       [ -e "$VCSH_COMMAND_PARAMETER" ] || fatal "'$VCSH_COMMAND_PARAMETER' does not exist" 1
        for VCSH_REPO_NAME in $(list); do
                for VCSH_FILE in $(get_files); do
-                       echo $VCSH_FILE | grep -q "$VCSH_COMMAND_PARAMETER" && echo "$VCSH_REPO_NAME: $VCSH_FILE"
+                       echo "$VCSH_FILE" | grep -q "$VCSH_COMMAND_PARAMETER" && echo "$VCSH_REPO_NAME: $VCSH_FILE"
                done
        done | sort -u
 }
 
 write_gitignore() {
+       # Don't do anything if the user does not want to write gitignore
+       if [ "x$VCSH_GITIGNORE" = 'xnone' ]; then
+               info "Not writing gitignore as '\$VCSH_GITIGNORE' is set to 'none'"
+               exit
+       fi
+
        use
        cd "$VCSH_BASE" || fatal "could not enter '$VCSH_BASE'" 11
+       OLDIFS=$IFS
+       IFS=$(printf '\n\t')
        gitignores=$(for file in $(git ls-files); do
                while true; do
-                       echo $file; new="${file%/*}"
-                       [ "$file" = "$new" ] && break
-                       file="$new"
+                       echo "$file"; new=${file%/*}
+                       [ x"$file" = x"$new" ] && break
+                       file=$new
                done;
        done | sort -u)
-       tempfile=$(mktemp) || fatal "could not create tempfile" 51
+
+       # Contrary to GNU mktemp, mktemp on BSD/OSX requires a template for temp files
+       # Using a template makes GNU mktemp default to $PWD and not #TMPDIR for tempfile location
+       # To make every OS happy, set full path explicitly
+       tempfile=$(mktemp "${TMPDIR:-/tmp}/tmp.XXXXXXXXXX") || fatal "could not create tempfile: '${tempfile}'" 51
+
        echo '*' > "$tempfile" || fatal "could not write to '$tempfile'" 57
        for gitignore in $gitignores; do
-               echo "$gitignore" | sed 's/^/!/' >> "$tempfile" || fatal "could not write to '$tempfile'" 57
-               if [ x$VCSH_GITIGNORE = x'recursive' ] && [ -d "$gitignore" ]; then
-                       { echo "$gitignore/*" | sed 's/^/!/' >> "$tempfile" || fatal "could not write to '$tempfile'" 57; }
+               echo "$gitignore" | sed 's@^@!/@' >> "$tempfile" || fatal "could not write to '$tempfile'" 57
+               if [ "x$VCSH_GITIGNORE" = 'xrecursive' ] && [ -d "$gitignore" ]; then
+                       { echo "$gitignore/*" | sed 's@^@!/@' >> "$tempfile" || fatal "could not write to '$tempfile'" 57; }
                fi
        done
+       IFS=$OLDIFS
        if diff -N "$tempfile" "$VCSH_BASE/.gitignore.d/$VCSH_REPO_NAME" > /dev/null; then
                rm -f "$tempfile" || error "could not delete '$tempfile'"
                exit
                fatal "could not move '$tempfile' to '$VCSH_BASE/.gitignore.d/$VCSH_REPO_NAME'" 53
 }
 
-if [ ! "x$VCSH_GITIGNORE" = 'xexact' ] && [ ! "x$VCSH_GITIGNORE" = 'xrecursive' ]; then
-       fatal "'\$VCSH_GITIGNORE' must be either 'exact' or 'recursive'" 1
+debug $(git version)
+
+if [ ! "x$VCSH_GITIGNORE" = 'xexact' ] && [ ! "x$VCSH_GITIGNORE" = 'xnone' ] && [ ! "x$VCSH_GITIGNORE" = 'xrecursive' ]; then
+       fatal "'\$VCSH_GITIGNORE' must equal 'exact', 'none', or 'recursive'" 1
 fi
 
-if [ "$1" = 'clone' ]; then
-       [ -z "$2" ] && fatal "$1: please specify a remote" 1
-       export VCSH_COMMAND="$1"
+VCSH_COMMAND=$1; export VCSH_COMMAND
+
+case $VCSH_COMMAND in
+       clon|clo|cl) VCSH_COMMAND=clone;;
+       commi|comm|com|co) VCSH_COMMAND=commit;;
+       delet|dele|del|de) VCSH_COMMAND=delete;;
+       ente|ent|en) VCSH_COMMAND=enter;;
+       hel|he) VCSH_COMMAND=help;;
+       ini|in) VCSH_COMMAND=init;;
+       pul) VCSH_COMMAND=pull;;
+       pus) VCSH_COMMAND=push;;
+       renam|rena|ren|re) VCSH_COMMAND=rename;;
+       ru) VCSH_COMMAND=run;;
+       statu|stat|sta|st) VCSH_COMMAND=status;;
+       upgrad|upgra|upgr|up) VCSH_COMMAND=upgrade;;
+       versio|versi|vers|ver|ve) VCSH_COMMAND=version;;
+       which|whi|wh) VCSH_COMMAND=which;;
+       write|writ|wri|wr) VCSH_COMMAND=write-gitignore;;
+esac    
+
+if [ x"$VCSH_COMMAND" = x'clone' ]; then
+       VCSH_BRANCH=
+       if [ "$2" = -b ]; then
+               VCSH_BRANCH=$3
+               shift
+               shift
+       fi
+       [ -z "$2" ] && fatal "$VCSH_COMMAND: please specify a remote" 1
        GIT_REMOTE="$2"
-       [ -n "$3" ] && VCSH_REPO_NAME="$3" || VCSH_REPO_NAME=$(basename "$GIT_REMOTE" .git)
+       [ -n "$VCSH_BRANCH" ] || if [ "$3" = -b ]; then
+               VCSH_BRANCH=$4
+               shift
+               shift
+       fi
+       if [ -n "$3" ]; then
+               VCSH_REPO_NAME=$3
+               [ -z "$VCSH_BRANCH" ] && [ "$4" = -b ] && VCSH_BRANCH=$5
+       else
+               VCSH_REPO_NAME=$(basename "${GIT_REMOTE#*:}" .git)
+       fi
+       [ -z "$VCSH_REPO_NAME" ] && fatal "$VCSH_COMMAND: could not determine repository name" 1
        export VCSH_REPO_NAME
-       export GIT_DIR="$VCSH_REPO_D/$VCSH_REPO_NAME.git"
-elif [ "$1" = 'which' ]; then
-       [ -z "$2" ] && fatal "$1: please specify a filename" 1
-       [ -n "$3" ] && fatal "$1: too many parameters" 1
-       export VCSH_COMMAND="$1"
-       export VCSH_COMMAND_PARAMETER="$2"
-elif [ "$1" = 'delete' ]           ||
-     [ "$1" = 'enter' ]            ||
-     [ "$1" = 'init' ]             ||
-     [ "$1" = 'list-tracked-by' ]  ||
-     [ "$1" = 'rename' ]           ||
-     [ "$1" = 'run' ]              ||
-     [ "$1" = 'setup' ]            ||
-     [ "$1" = 'write-gitignore' ]; then
-       [ -z $2 ]                      && fatal "$1: please specify repository to work on" 1
-       [ "$1" = 'rename' -a -z "$3" ] && fatal "$1: please specify a target name" 1
-       [ "$1" = 'run' -a -z "$3" ]    && fatal "$1: please specify a command" 1
-       export VCSH_COMMAND="$1"
-       export VCSH_REPO_NAME="$2"
-       export GIT_DIR="$VCSH_REPO_D/$VCSH_REPO_NAME.git"
-       [ "$VCSH_COMMAND" = 'rename' ]         && export GIT_DIR_NEW="$VCSH_REPO_D/$3.git"
-       [ "$VCSH_COMMAND" = 'run' ] && shift 2 && export VCSH_EXTERNAL_COMMAND="$*"
-       [ "$VCSH_COMMAND" = 'write-gitignore' ]
-elif [ "$1" = 'list' ] ||
-     [ "$1" = 'list-tracked' ]; then
-       export VCSH_COMMAND="$1"
+       [ -n "$VCSH_BRANCH" ] || VCSH_BRANCH=master
+       GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+elif [ "$VCSH_COMMAND" = 'version' ]; then
+       echo "$SELF $VERSION"
+       git version
+       exit
+elif [ x"$VCSH_COMMAND" = x'which' ]; then
+       [ -z "$2" ] && fatal "$VCSH_COMMAND: please specify a filename" 1
+       [ -n "$3" ] && fatal "$VCSH_COMMAND: too many parameters" 1
+       VCSH_COMMAND_PARAMETER=$2; export VCSH_COMMAND_PARAMETER
+elif [ x"$VCSH_COMMAND" = x'delete' ]           ||
+     [ x"$VCSH_COMMAND" = x'enter' ]            ||
+     [ x"$VCSH_COMMAND" = x'init' ]             ||
+     [ x"$VCSH_COMMAND" = x'list-tracked-by' ]  ||
+     [ x"$VCSH_COMMAND" = x'rename' ]           ||
+     [ x"$VCSH_COMMAND" = x'run' ]              ||
+     [ x"$VCSH_COMMAND" = x'upgrade' ]          ||
+     [ x"$VCSH_COMMAND" = x'write-gitignore' ]; then
+       [ -z "$2" ]                                     && fatal "$VCSH_COMMAND: please specify repository to work on" 1
+       [ x"$VCSH_COMMAND" = x'rename' ] && [ -z "$3" ] && fatal "$VCSH_COMMAND: please specify a target name" 1
+       [ x"$VCSH_COMMAND" = x'run'    ] && [ -z "$3" ] && fatal "$VCSH_COMMAND: please specify a command" 1
+       VCSH_REPO_NAME=$2; export VCSH_REPO_NAME
+       GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+       [ x"$VCSH_COMMAND" = x'rename' ] && { VCSH_REPO_NAME_NEW=$3; export VCSH_REPO_NAME_NEW;
+                                             GIT_DIR_NEW=$VCSH_REPO_D/$VCSH_REPO_NAME_NEW.git; export GIT_DIR_NEW; }
+       [ x"$VCSH_COMMAND" = x'run' ]    && shift 2
+elif [ x"$VCSH_COMMAND" = x'commit' ] ||
+     [ x"$VCSH_COMMAND" = x'list'   ] ||
+     [ x"$VCSH_COMMAND" = x'list-tracked' ] ||
+     [ x"$VCSH_COMMAND" = x'list-untracked' ] ||
+     [ x"$VCSH_COMMAND" = x'pull'   ] ||
+     [ x"$VCSH_COMMAND" = x'push'   ]; then
+       :
+elif [ x"$VCSH_COMMAND" = x'status' ]; then
+       VCSH_REPO_NAME=$2; export VCSH_REPO_NAME
 elif [ -n "$2" ]; then
-       export VCSH_COMMAND='run'
-       export VCSH_REPO_NAME="$1"
-       export GIT_DIR="$VCSH_REPO_D/$VCSH_REPO_NAME.git"
-       [ -d $GIT_DIR ] || { help; exit 1; }
+       VCSH_COMMAND='run'; export VCSH_COMMAND
+       VCSH_REPO_NAME=$1; export VCSH_REPO_NAME
+       GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+       [ -d "$GIT_DIR" ] || { help; exit 1; }
        shift 1
-       export VCSH_EXTERNAL_COMMAND="git $*"
-elif [ -n "$1" ]; then
-       export VCSH_COMMAND='enter'
-       export VCSH_REPO_NAME="$1"
-       export GIT_DIR="$VCSH_REPO_D/$VCSH_REPO_NAME.git"
-       [ -d $GIT_DIR ] || { help; exit 1; }
+       set -- "git" "$@"
+elif [ -n "$VCSH_COMMAND" ]; then
+       VCSH_COMMAND='enter'; export VCSH_COMMAND
+       VCSH_REPO_NAME=$1; export VCSH_REPO_NAME
+       GIT_DIR=$VCSH_REPO_D/$VCSH_REPO_NAME.git; export GIT_DIR
+       [ -d "$GIT_DIR" ] || { help; exit 1; }
 else
        # $1 is empty, or 'help'
        help && exit
 
 # Did we receive a directory instead of a name?
 # Mangle the input to fit normal operation.
-if echo $VCSH_REPO_NAME | grep -q '/'; then
-       export GIT_DIR=$VCSH_REPO_NAME
-       export VCSH_REPO_NAME=$(basename "$VCSH_REPO_NAME" .git)
+if echo "$VCSH_REPO_NAME" | grep -q '/'; then
+       GIT_DIR=$VCSH_REPO_NAME; export GIT_DIR
+       VCSH_REPO_NAME=$(basename "$VCSH_REPO_NAME" .git); export VCSH_REPO_NAME
 fi
 
-
-for check_directory in "$VCSH_REPO_D" "$VCSH_BASE/.gitignore.d"
-do
+check_dir() {
+       check_directory="$1"
        if [ ! -d "$check_directory" ]; then
                if [ -e "$check_directory" ]; then
                        fatal "'$check_directory' exists but is not a directory" 13
                else
-                       info "attempting to create '$check_directory'"
+                       verbose "attempting to create '$check_directory'"
                        mkdir -p "$check_directory" || fatal "could not create '$check_directory'" 50
                fi
        fi
-done
+}
+
+check_dir "$VCSH_REPO_D"
+[ ! "x$VCSH_GITIGNORE" = 'xnone' ] && check_dir "$VCSH_BASE/.gitignore.d"
+[ ! "x$VCSH_GITATTRIBUTES" = 'xnone' ] && check_dir "$VCSH_BASE/.gitattributes.d"
 
 verbose "$VCSH_COMMAND begin"
-export VCSH_COMMAND=$(echo $VCSH_COMMAND | sed 's/-/_/g')
+VCSH_COMMAND=$(echo "$VCSH_COMMAND" | sed 's/-/_/g'); export VCSH_COMMAND
+
+# Source repo-specific configuration file
+[ -r "$XDG_CONFIG_HOME/vcsh/config.d/$VCSH_REPO_NAME" ] && . "$XDG_CONFIG_HOME/vcsh/config.d/$VCSH_REPO_NAME"
+
+# source overlay functions
+for overlay in "$VCSH_OVERLAY_D/$VCSH_COMMAND"* "$VCSH_OVERLAY_D/$VCSH_REPO_NAME.$VCSH_COMMAND"*; do
+       [ -r "$overlay" ] || continue
+       info "sourcing '$overlay'"
+       . "$overlay"
+done
+
 hook pre-command
-$VCSH_COMMAND
+$VCSH_COMMAND "$@"
 hook post-command
 verbose "$VCSH_COMMAND end, exiting"
+exit $VCSH_COMMAND_RETURN_CODE