nc-restore: Check for free space in $TMPDIR before extracting tar file

bin/ncp/BACKUPS/nc-restore.sh

@@ -37,10 +37,20 @@ cleanup(){  local RET=$?; echo "Cleanup..."; rm -rf "${TMPDIR}"; trap "" EXIT; e
 trap cleanup INT TERM HUP ERR EXIT
 rm -rf "$TMPDIR" && mkdir -p "$TMPDIR"
 
+[[ "$BACKUPFILE" =~ ".tar.gz" ]] && compress_arg="-I pigz"
+
+# CHECK FREE SPACE IN $TMPDIR
+echo "check free space..." # allow at least ~100 extra MiB
+extractedsize=$(tar $compress_arg -tvf "$BACKUPFILE" | awk '{s+=$3} END{printf "%.0f", (s/1024)}') # Size of extracted files in "KB"
+size=$(($extractedsize + 100*1024))
+free=$( df "$TMPDIR" | tail -1 | awk '{ print $4 }' )
+[ $size -ge $free ] && {
+  echo "free space check failed. Need $size KB in $TMPDIR";
+  exit 1;
+}
+
 # EXTRACT FILES
 echo "extracting backup file $BACKUPFILE..."
-
-[[ "$BACKUPFILE" =~ ".tar.gz" ]] && compress_arg="-I pigz"
 tar $compress_arg -xf "$BACKUPFILE" -C "$TMPDIR" || exit 1
 
 ## SANITY CHECKS