scripts/env

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