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 --color | grep -vE '^. master$'
 100 }
 101
 102 env_diff() {
 103         env_init
 104         env_sync_data
 105         git diff --cached --color
 106         env_link_config
 107 }
 108
 109 env_save() {
 110         env_init
 111         env_sync
 112         env_link_config
 113 }
 114
 115 env_revert() {
 116         env_init
 117         env_do_reset
 118         env_link_config
 119 }
 120
 121 env_ask_sync() {
 122         env_sync_data
 123         LINES="$(env_diff | wc -l)" # implies env_init
 124         [ "$LINES" -gt 0 ] && {
 125                 if ask_bool 1 "Do you want to save your changes"; then
 126                         env_sync
 127                 else
 128                         env_do_reset
 129                 fi
 130         }
 131 }
 132
 133 env_clear() {
 134         env_init
 135         [ -L "$BASEDIR/.config" ] && rm -f "$BASEDIR/.config"
 136         [ -L "$BASEDIR/files" ] && rm -f "$BASEDIR/files"
 137         [ -f "$ENVDIR/.config" ] || ( cd "$ENVDIR/files" && find | grep -vE '^\.$' > /dev/null )
 138         env_sync_data
 139         if ask_bool 1 "Do you want to keep your current config and files"; then
 140                 mkdir -p "$BASEDIR/files"
 141                 shopt -s dotglob
 142                 cp -a "$ENVDIR/files/"* "$BASEDIR/files" 2>/dev/null >/dev/null
 143                 shopt -u dotglob
 144                 cp "$ENVDIR/.config" "$BASEDIR/"
 145         else
 146                 rm -rf "$BASEDIR/files" "$BASEDIR/.config"
 147         fi
 148         cd "$BASEDIR"
 149         rm -rf "$ENVDIR"
 150 }
 151
 152 env_delete() {
 153         local name="${1##*/}"
 154         env_init
 155         [ -z "$name" ] && usage
 156         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 157         [ "$name" = "$branch" ] && error "cannot delete the currently selected environment"
 158         git branch -D "$name"
 159 }
 160
 161 env_switch() {
 162         local name="${1##*/}"
 163         [ -z "$name" ] && usage
 164
 165         env_init
 166         env_ask_sync
 167         git checkout "$name" || error "environment '$name' not found"
 168         env_link_config
 169 }
 170
 171 env_rename() {
 172         local NAME="${1##*/}"
 173         env_init
 174         git branch -m "$NAME"
 175 }
 176
 177 env_new() {
 178         local NAME="$1"
 179         local branch
 180         local from="master"
 181
 182         [ -z "$NAME" ] && usage
 183         env_init 1
 184
 185         branch="$(git branch | grep '^\* ' | awk '{print $2}')"
 186         if [ -n "$branch" -a "$branch" != "master" ]; then
 187                 env_ask_sync
 188                 if ask_bool 0 "Do you want to clone the current environment?"; then
 189                         from="$branch"
 190                 fi
 191                 rm -f "$BASEDIR/.config" "$BASEDIR/files"
 192         fi
 193         git checkout -b "$1" "$from"
 194         if [ -f "$BASEDIR/.config" -o -d "$BASEDIR/files" ]; then
 195                 if ask_bool 1 "Do you want to start your configuration repository with the current configuration?"; then
 196                         [ -d "$BASEDIR/files" -a \! -L "$BASEDIR/files" ] && {
 197                                 mkdir -p "$ENVDIR/files"
 198                                 shopt -s dotglob
 199                                 mv "$BASEDIR/files/"* "$ENVDIR/files/" 2>/dev/null
 200                                 shopt -u dotglob
 201                                 rmdir "$BASEDIR/files"
 202                         }
 203                         env_sync
 204                 else
 205                         rm -rf "$BASEDIR/.config" "$BASEDIR/files"
 206                 fi
 207         fi
 208         env_link_config
 209 }
 210
 211 COMMAND="$1"; shift
 212 case "$COMMAND" in
 213         help) usage 0;;
 214         new) env_new "$@";;
 215         list) env_list "$@";;
 216         clear) env_clear "$@";;
 217         switch) env_switch "$@";;
 218         delete) env_delete "$@";;
 219         rename) env_rename "$@";;
 220         diff) env_diff "$@";;
 221         save) env_save "$@";;
 222         revert) env_revert "$@";;
 223         *) usage;;
 224 esac