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
+  check that all output goes to current TTY
-  sync before and after creating the image
+
 package selections:
   desktop
     icewm-full

opt/system-image

@@ -7,63 +7,42 @@ 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")
-
-for I in ${!MOUNT_LIST[@]}; do
-  if [ ! -z "${MOUNT_LIST[$I]}" ]; then
-    FOUND=0
-    for J in ${!EXCLUDE_LIST[@]}; do
-      if grep "${EXCLUDE_LIST[$J]}" > /dev/null <<< "${MOUNT_LIST[$I]}"; then
-        FOUND=1
-        break
-      fi
-    done
-    # if no parent dir of ${MOUNT_LIST[$I]} is found in $EXCLUDE_LIST
-    if [ $FOUND -eq 0 ]; then
-      EXCLUDE_LIST+=("${MOUNT_LIST[$I]}")
-    fi
-  fi
-done
-
-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
-
 #TODO: refuse to run if system is running
 
-#TODO: add a way to force a new system image up without asking (for example a file in /run/void-usb)
+#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 "Create a new system image?
+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,
@@ -76,13 +55,47 @@ Creating a new system image will take some time.
 "
 
 if yesno; then
-  echo "Building image..."
+  echo_tty -n "Generating exclusion list... "
-  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
+  # cutting off the leading slash allows us to just ignore empty lines below
-  #TODO: check if enough disk space
+  readarray -t MOUNT_LIST <<< "$(findmnt --output TARGET --noheadings --raw | sed -e 's|^/||' | sort)"
-  # yes -> create new image next to old image
+  # always ignore /tmp and the package cache
-  # no  -> create new image in RAM
+  EXCLUDE_LIST=("tmp" "var/cache/xbps")
-  #TODO: figure out when appending to existing squashfs is a good idea
+
+  for I in ${!MOUNT_LIST[@]}; do
+    if [ ! -z "${MOUNT_LIST[$I]}" ]; then
+      FOUND=0
+      for J in ${!EXCLUDE_LIST[@]}; do
+        if grep "${EXCLUDE_LIST[$J]}" > /dev/null <<< "${MOUNT_LIST[$I]}"; then
+          FOUND=1
+          break
+        fi
+      done
+      # if no parent dir of ${MOUNT_LIST[$I]} is found in $EXCLUDE_LIST
+      if [ $FOUND -eq 0 ]; then
+        EXCLUDE_LIST+=("${MOUNT_LIST[$I]}")
+      fi
+    fi
+  done
+
+  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
+  echo_tty "done"
+
+  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
+
+  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"