scripts/env

   1 #!/usr/bin/env bash
   2 BASEDIR="$PWD"
   3 ENVDIR="$PWD/env"
   4 export GREP_OPTIONS=
   5
   6 usage() {
   7         cat <<EOF
   8 Usage: $0 [options] <command> [arguments]
   9 Commands:
  10         help              This help text
  11         list              List environments
  12         clear             Delete all environment and revert to flat config/files
  13         new <name>        Create a new environment
  14         switch <name>     Switch to a different environment
  15         delete <name>     Delete an environment
  16         rename <newname>  Rename the current environment
  17         diff              Show differences between current state and environment
  18         save [message]    Save your changes to the environment, optionally using
  19                           the given commit message
  20         revert            Revert your changes since last save
  21
  22 Options:
  23
  24 EOF
  25         exit ${1:-1}
  26 }
  27
  28 error() {
  29         echo "$0: $*"
  30         exit 1
  31 }
  32
  33 ask_bool() {
  34         local DEFAULT="$1"; shift
  35         local def defstr val
  36         case "$DEFAULT" in
  37                 1) def=0; defstr="Y/n";;
  38                 0) def=1; defstr="y/N";;
  39                 *) def=;  defstr="y/n";;
  40         esac
  41         while [ -z "$val" ]; do
  42                 local VAL
  43
  44                 echo -n "$* ($defstr): "
  45                 read VAL
  46                 case "$VAL" in
  47                         y*|Y*) val=0;;
  48                         n*|N*) val=1;;
  49                         *) val="$def";;
  50                 esac
  51         done
  52         return "$val"
  53 }
  54
  55 env_init() {
  56         local CREATE="$1"
  57         if [ -z "$CREATE" ]; then
  58                 [ -d "$ENVDIR" ] || exit 0
  59         fi
  60         [ -x "$(which git 2>/dev/null)" ] || error "Git is not installed"
  61         mkdir -p "$ENVDIR" || error "Failed to create the environment directory"
  62         cd "$ENVDIR" || error "Failed to switch to the environment directory"
  63         [ -d .git ] || {
  64                 git init &&
  65                 touch .config &&
  66                 mkdir files &&
  67                 git add . &&
  68                 git commit -q -m "Initial import"
  69         } || {
  70                 rm -rf .git
  71                 error "Failed to initialize the environment directory"
  72         }
  73 }
  74
  75 env_sync_data() {
  76         [ \! -L "$BASEDIR/.config" -a -f "$BASEDIR/.config" ] && mv "$BASEDIR/.config" "$ENVDIR"
  77         git add .
  78         git add -u
  79 }
  80
  81 env_sync() {
  82         local STR="$1"
  83         env_sync_data
  84         git commit -m "${STR:-Update} at $(date)"
  85 }
  86
  87 env_link_config() {
  88         rm -f "$BASEDIR/.config"
  89         ln -s env/.config "$BASEDIR/.config"
  90         mkdir -p "$ENVDIR/files"
  91         [ -L "$BASEDIR/files" ] || ln -s env/files "$BASEDIR/files"
  92 }
  93
  94 env_do_reset() {
  95         git reset --hard HEAD
  96         git clean -d -f
  97 }
  98
  99 env_list() {
 100         env_init
 101         git branch --color | grep -vE '^. master$'
 102 }
 103
 104 env_diff() {
 105         env_init
 106         env_sync_data
 107         git diff --cached --color
 108         env_link_config
 109 }
 110
 111 env_save() {
 112         env_init
 113         env_sync "$@"
 114         env_link_config
 115 }
 116
 117 env_revert() {
 118         env_init
 119         env_do_reset
 120         env_link_config
 121 }
 122
 123 env_ask_sync() {
 124         env_sync_data
 125         LINES="$(env_diff | wc -l)" # implies env_init
 126         [ "$LINES" -gt 0 ] && {
 127                 if ask_bool 1 "Do you want to save your changes"; then
 128                         env_sync
 129                 else
 130                         env_do_reset
 131                 fi
 132         }
 133 }
 134
 135 env_clear() {
 136         env_init
 137         [ -L "$BASEDIR/.config" ] && rm -f "$BASEDIR/.config"
 138         [ -L "$BASEDIR/files" ] && rm -f "$BASEDIR/files"
 139         [ -f "$ENVDIR/.config" ] || ( cd "$ENVDIR/files" && find | grep -vE '^\.$' > /dev/null )
 140         env_sync_data
 141         if ask_bool 1 "Do you want to keep your current config and files"; then
 142                 mkdir -p "$BASEDIR/files"
 143                 shopt -s dotglob
 144                 cp -a "$ENVDIR/files/"* "$BASEDIR/files" 2>/dev/null >/dev/null
 145                 shopt -u dotglob
 146                 cp "$ENVDIR/.config" "$BASEDIR/"
 147         else
 148                 rm -rf "$BASEDIR/files" "$BASEDIR/.config"
 149         fi
 150         cd "$BASEDIR"
 151         rm -rf "$ENVDIR"
 152 }
 153
 154 env_delete() {
 155         local name="${1##*/}"
 156         env_init
 157         [ -z "$name" ] && usage
 158         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 159         [ "$name" = "$branch" ] && error "cannot delete the currently selected environment"
 160         git branch -D "$name"
 161 }
 162
 163 env_switch() {
 164         local name="${1##*/}"
 165         [ -z "$name" ] && usage
 166
 167         env_init
 168         env_ask_sync
 169         git checkout "$name" || error "environment '$name' not found"
 170         env_link_config
 171 }
 172
 173 env_rename() {
 174         local NAME="${1##*/}"
 175         env_init
 176         git branch -m "$NAME"
 177 }
 178
 179 env_new() {
 180         local NAME="$1"
 181         local branch
 182         local from="master"
 183
 184         [ -z "$NAME" ] && usage
 185         env_init 1
 186
 187         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 188         if [ -n "$branch" -a "$branch" != "master" ]; then
 189                 env_ask_sync
 190                 if ask_bool 0 "Do you want to clone the current environment?"; then
 191                         from="$branch"
 192                 fi
 193                 rm -f "$BASEDIR/.config" "$BASEDIR/files"
 194         fi
 195         git checkout -b "$1" "$from"
 196         if [ -f "$BASEDIR/.config" -o -d "$BASEDIR/files" ]; then
 197                 if ask_bool 1 "Do you want to start your configuration repository with the current configuration?"; then
 198                         [ -d "$BASEDIR/files" -a \! -L "$BASEDIR/files" ] && {
 199                                 mkdir -p "$ENVDIR/files"
 200                                 shopt -s dotglob
 201                                 mv "$BASEDIR/files/"* "$ENVDIR/files/" 2>/dev/null
 202                                 shopt -u dotglob
 203                                 rmdir "$BASEDIR/files"
 204                         }
 205                         env_sync
 206                 else
 207                         rm -rf "$BASEDIR/.config" "$BASEDIR/files"
 208                 fi
 209         fi
 210         env_link_config
 211 }
 212
 213 COMMAND="$1"; shift
 214 case "$COMMAND" in
 215         help) usage 0;;
 216         new) env_new "$@";;
 217         list) env_list "$@";;
 218         clear) env_clear "$@";;
 219         switch) env_switch "$@";;
 220         delete) env_delete "$@";;
 221         rename) env_rename "$@";;
 222         diff) env_diff "$@";;
 223         save) env_save "$@";;
 224         revert) env_revert "$@";;
 225         *) usage;;
 226 esac