system-image: send all output to $TTY_OR_CONSOLE, generate exclusion list only if building image, sync at the end

notes_to_self.txt

@@ -29,8 +29,8 @@ when shutting down, let Xorg exit first, then run `loginctl {poweroff,reboot}`
 add polkit to common packages
 https://github.com/aarnt/octoxbps
 system-image
-  make all output appear on current TTY
-  sync before and after creating the image
+  check that all output goes to current TTY
+
 package selections:
   desktop
     icewm-full

opt/system-image

@@ -7,34 +7,61 @@ else
   TTY_OR_CONSOLE="/dev/console"
 fi
 
+function echo_tty {
+  if [ "$1" = "-n" ]; then
+    shift
+    echo -n "$@" > $TTY_OR_CONSOLE
+  else
+    echo "$@" > $TTY_OR_CONSOLE
+  fi
+}
 
 function yesno {
   unset DISCARD_ME
   while [ -z "$DISCARD_ME" ]; do
-    read -p "[y/n] " -n1 DISCARD_ME < $TTY_OR_CONSOLE
+    read -p "[y/n] " -n1 DISCARD_ME < $TTY_OR_CONSOLE > $TTY_OR_CONSOLE
     case "$DISCARD_ME" in
       y)
-        echo ""
+        echo_tty
         return 0
         ;;
       n)
-        echo ""
+        echo_tty
         return 1
         ;;
       *)
-        echo " Please enter y for yes or n for no."
+        echo_tty " Please enter y for yes or n for no."
         unset DISCARD_ME
         ;;
     esac
   done
 }
 
-# cutting off the leading slash allows us to just ignore empty lines below
-readarray -t MOUNT_LIST <<< "$(findmnt --output TARGET --noheadings --raw | sed -e 's|^/||' | sort)"
-# always ignore /tmp and the package cache
-EXCLUDE_LIST=("tmp" "var/cache/xbps")
+#TODO: refuse to run if system is running
 
-for I in ${!MOUNT_LIST[@]}; do
+#TODO: add a way to force a new system image without asking (for example a file in /run/void-usb)
+
+#TODO: colors (bright white / light gray for readability)
+echo_tty "Create a new system image?
+
+This will replace the existing system image with a snapshot of the currently
+running system. Choosing no here will discard any newly installed programs,
+updates, system configuration changes, etc.
+
+This should not affect your files in /home as they are stored to disk directly.
+Check /TODO/README.txt for more information.
+
+Creating a new system image will take some time.
+"
+
+if yesno; then
+  echo_tty -n "Generating exclusion list... "
+  # cutting off the leading slash allows us to just ignore empty lines below
+  readarray -t MOUNT_LIST <<< "$(findmnt --output TARGET --noheadings --raw | sed -e 's|^/||' | sort)"
+  # always ignore /tmp and the package cache
+  EXCLUDE_LIST=("tmp" "var/cache/xbps")
+
+  for I in ${!MOUNT_LIST[@]}; do
     if [ ! -z "${MOUNT_LIST[$I]}" ]; then
       FOUND=0
       for J in ${!EXCLUDE_LIST[@]}; do
@@ -48,41 +75,27 @@ for I in ${!MOUNT_LIST[@]}; do
         EXCLUDE_LIST+=("${MOUNT_LIST[$I]}")
       fi
     fi
-done
+  done
 
-touch /run/void-usb/system-image-excludes
-touch /run/void-usb/system-image-pseudo
-for I in ${!EXCLUDE_LIST[@]}; do
+  touch /run/void-usb/system-image-excludes
+  touch /run/void-usb/system-image-pseudo
+  for I in ${!EXCLUDE_LIST[@]}; do
     echo "/${EXCLUDE_LIST[$I]}" >> /run/void-usb/system-image-excludes
     FILE_PERMS="$(stat -c '%a %u %g' "${EXCLUDE_LIST[$I]}")"
     echo "\"/${EXCLUDE_LIST[$I]}\" d $FILE_PERMS" >> /run/void-usb/system-image-pseudo
-done
+  done
+  echo_tty "done"
 
-#TODO: refuse to run if system is running
+  echo_tty "Building image..."
+  mksquashfs / /run/void-usb/container/new_squashfs.img -b 1M -comp xz -progress -noappend -pf /run/void-usb/system-image-pseudo -ef /run/void-usb/system-image-excludes > $TTY_OR_CONSOLE
 
-#TODO: add a way to force a new system image up without asking (for example a file in /run/void-usb)
-
-#TODO: colors (bright white / light gray for readability)
-echo "Create a new system image?
-
-This will replace the existing system image with a snapshot of the currently
-running system. Choosing no here will discard any newly installed programs,
-updates, system configuration changes, etc.
-
-This should not affect your files in /home as they are stored to disk directly.
-Check /TODO/README.txt for more information.
-
-Creating a new system image will take some time.
-"
-
-if yesno; then
-  echo "Building image..."
-  mksquashfs / /run/void-usb/container/new_squashfs.img -b 1M -comp xz -progress -noappend -pf /run/void-usb/system-image-pseudo -ef /run/void-usb/system-image-excludes
-  #TODO: check if enough disk space
-  # yes -> create new image next to old image
-  # no  -> create new image in RAM
-  #TODO: figure out when appending to existing squashfs is a good idea
+  echo_tty -n "Moving new image in place... "
   mv /run/void-usb/container/new_squashfs.img /run/void-usb/container/squashfs.img
+  echo_tty "done"
 else
-  echo "Discarding system changes."
+  echo_tty "Discarding system changes."
 fi
+
+echo_tty -n "Syncing... "
+sync
+echo_tty "done"