Refactor mcbe_backup regex

Escape Docker container once
Don't escape ) right parenthesis for grep -E
Rename escape variables

src/mcbe_backup.py

@@ -26,12 +26,9 @@ def server_do(cmd: str) -> typing.Union[str, None, datetime.datetime]:
     :return: systemd cursor or time for server_read
     """
     if ARGS.docker:
-        # Escape r'][(){}:,!!\" ' for socat address specifications and command line
-        service_esc = re.sub(r'([\\" ])', r"\\\\\\\1", SERVICE)
-        service_esc = re.sub("([][(){}:,!])", r"\\\1", service_esc)
         cmd_cursor = datetime.datetime.now().astimezone()
         subprocess.run(
-            ["socat", "-", f"EXEC:docker container attach -- {service_esc},pty"],
+            ["socat", "-", f"EXEC:docker container attach -- {SERVICE_SOCAT},pty"],
             check=True,
             input=cmd + "\n",
             stdout=subprocess.DEVNULL,
@@ -118,7 +115,7 @@ def server_read(cmd_cursor: typing.Union[str, None, datetime.datetime]) -> str:
     sys.exit(
         f"No world {WORLD} in {WORLDS_DIR}, check level-name in server.properties too"
     )
-WORLD_ESC = re.escape(WORLD)
+WORLD_REGEX = re.escape(WORLD)
 if ARGS.docker:
     TEMP_DIR = pathlib.Path("/tmp/docker_mcbe_backup", SERVER_DIR.parent.name)
 else:
@@ -143,6 +140,9 @@ def server_read(cmd_cursor: typing.Union[str, None, datetime.datetime]) -> str:
         != "running"
     ):
         sys.exit(f"Container {SERVICE} not running")
+    # Escape r'][(){}:,!!\" ' for socat address specifications and command-line
+    SERVICE_SOCAT = re.sub(r'([\\" ])', r"\\\\\\\1", SERVICE)
+    SERVICE_SOCAT = re.sub("([][(){}:,!])", r"\\\1", SERVICE_SOCAT)
 else:
     # Trim off SERVICE after last .service
     if SERVICE.endswith(".service"):
@@ -211,7 +211,7 @@ def server_read(cmd_cursor: typing.Union[str, None, datetime.datetime]) -> str:
     # {WORLD}not :...:#...
     # Minecraft Bedrock Edition says file:bytes, file:bytes, ...
     # journald LineMax splits lines so delete newlines
-    files = re.findall(f"{WORLD_ESC}[^:]+:[0-9]+", QUERY.replace(os.linesep, ""))
+    files = re.findall(f"{WORLD_REGEX}[^:]+:[0-9]+", QUERY.replace(os.linesep, ""))
 
     TEMP_DIR.mkdir(parents=True, exist_ok=True)
     # zip restores path of directory given to it (WORLD), not just the directory itself

src/mcbe_backup.sh

@@ -15,12 +15,8 @@ syntax='Usage: mcbe_backup.sh [OPTION]... SERVER_DIR SERVICE'
 # echo "$*" to $service input
 server_do() {
 	if [ "$docker" = true ]; then
-		# Escape '][(){}:,!!\" ' for socat address specifications and command line
-		local service_esc
-		service_esc=$(echo "$service" | sed -Ee 's/([\" ])/\\\\\\\1/g')
-		service_esc=$(echo "$service_esc" | sed -Ee 's/([][(){}:,!])/\\\1/g')
 		date --iso-8601=ns
-		echo "$*" | socat - EXEC:"docker container attach -- $service_esc",pty > /dev/null
+		echo "$*" | socat - EXEC:"docker container attach -- $service_socat",pty > /dev/null
 	else
 		{
 			journalctl "_SYSTEMD_UNIT=$service.service" --show-cursor -n 0 -o cat || true
@@ -100,7 +96,8 @@ if [ ! -d "$worlds_dir/$world" ]; then
 	>&2 echo "No world $world in $worlds_dir, check level-name in server.properties too"
 	exit 1
 fi
-world_esc=$(echo "$world" | sed -Ee 's/([.?*+{|()[\^$])/\\\1/g')
+# Escape '.?*+{|([\^$' for grep -E
+world_regex=$(echo "$world" | sed -Ee 's/([.?*+{|([\^$])/\\\1/g')
 if [ "$docker" = true ]; then
 	temp_dir=/tmp/docker_mcbe_backup/$(basename "$(dirname "$server_dir")")
 else
@@ -113,6 +110,9 @@ if [ "$docker" = true ]; then
 		>&2 echo "Container $service not running"
 		exit 1
 	fi
+	# Escape '][(){}:,!!\" ' for socat address specifications and command-line
+	service_socat=$(echo "$service" | sed -Ee 's/([\" ])/\\\\\\\1/g')
+	service_socat=$(echo "$service_socat" | sed -Ee 's/([][(){}:,!])/\\\1/g')
 else
 	# Trim off $2 after last .service
 	service=${2%.service}
@@ -176,7 +176,7 @@ done
 # Minecraft Bedrock Edition says $file:$bytes, $file:$bytes, ...
 # journald LineMax splits lines so delete newlines
 # shellcheck disable=SC1087
-files=$(echo "$query" | tr -d '\n' | grep -Eo -- "$world_esc[^:]+:[0-9]+")
+files=$(echo "$query" | tr -d '\n' | grep -Eo -- "$world_regex[^:]+:[0-9]+")
 
 mkdir -p "$temp_dir"
 # zip restores path of directory given to it ($world), not just the directory itself

tests/test_mcbe.sh

@@ -247,7 +247,7 @@ echo 'Test mcbe-backup@testme level-name flag injection'
 test_backup
 
 systemctl stop "mcbe@$instance.socket"
-sed -ie 's/^level-name=.*/level-name=.+{()[^$/' "$properties"
+sed -ie 's/^level-name=.*/level-name=.+{([^$/' "$properties"
 start_server
 
 echo 'Test mcbe-backup@testme level-name regex injection'