commit d86ec87c95ae47ac634cc7f43f490eacf49f7d98
Author: x1a0 <zhangxiao@xzhang.net>
Date:   Fri May 15 14:38:26 2026 +0200

    Hello, blightmud-batmud-logger

diff --git a/.luarc.json b/.luarc.json
new file mode 100644
index 0000000..bd043f9
--- /dev/null
+++ b/.luarc.json
@@ -0,0 +1,3 @@
+{
+  "Lua.diagnostics.globals": ["cformat", "mud"]
+}
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..572c07b
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,15 @@
+FROM alpine:3.19
+
+# zstd for compression, tzdata so cron fires at correct local time
+RUN apk add --no-cache zstd tzdata
+
+COPY compress.sh /usr/local/bin/compress.sh
+RUN chmod +x /usr/local/bin/compress.sh
+
+# Install crontab: run compress at 02:00 every night
+RUN echo "0 2 * * * /usr/local/bin/compress.sh > /proc/1/fd/1 2>&1" \
+    | crontab -
+
+# crond -f: foreground (required for containers)
+# crond -l 2: log level warning and above
+CMD ["crond", "-f", "-l", "2"]
diff --git a/compress.sh b/compress.sh
new file mode 100644
index 0000000..478e100
--- /dev/null
+++ b/compress.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env sh
+# Compress all .log files not modified today across all character subdirs.
+# Expects /logs to be mounted from the host.
+
+LOG_DIR="${LOG_DIR:-/logs}"
+TODAY=$(date +%Y-%m-%d)
+
+find "$LOG_DIR" -maxdepth 2 -name "*.log" | while read -r f; do
+  FILE_DATE=$(date -r "$f" +%Y-%m-%d 2>/dev/null)
+
+  if [ "$FILE_DATE" = "$TODAY" ]; then
+    echo "[$(date +%H:%M:%S)] Skipping active log: $f"
+    continue
+  fi
+
+  echo "[$(date +%H:%M:%S)] Compressing: $f"
+  if zstd -19 --rm -q "$f"; then
+    echo "[$(date +%H:%M:%S)] Done: ${f}.zst"
+  else
+    echo "[$(date +%H:%M:%S)] ERROR compressing: $f" >&2
+  fi
+done
+
+echo "[$(date +%H:%M:%S)] Compression run complete."
diff --git a/main.lua b/main.lua
new file mode 100644
index 0000000..08f0d3f
--- /dev/null
+++ b/main.lua
@@ -0,0 +1,44 @@
+OUTPUT = ":"
+INPUT = ">"
+
+local current_log_filepath = nil
+local current_log_file = nil
+
+local get_current_log_filepath = function()
+    local date = os.date("%Y-%m-%d")
+    local data_home = os.getenv("XDG_DATA_HOME") or string.format("%s/.local/share", os.getenv("HOME"))
+    return string.format("%s/blightmud/logs/batmud/%s/%s.log", data_home, os.getenv("BATMUD_CHAR"), date)
+end
+
+local write_log = function(line, type)
+    local path = get_current_log_filepath()
+    if current_log_filepath == nil or current_log_filepath ~= path then
+        current_log_filepath = path
+        os.execute(string.format("mkdir -p %q", path:match("^(.*)/[^/]+$")))
+        current_log_file = assert(io.open(path, "a"))
+    end
+
+    local log_line = cformat("<black>[%s]%s<reset> %s\n", os.date("%H:%M:%S"), type, line)
+    if current_log_file ~= nil then
+        assert(current_log_file:write(log_line))
+        assert(current_log_file:flush())
+    end
+end
+
+mud.add_output_listener(function(line)
+    if not line:skip_log() then
+        if line:replacement() == nil then
+            write_log(line:raw(), OUTPUT)
+        else
+            write_log(line:replacement(), OUTPUT)
+        end
+    end
+    return line
+end)
+
+mud.add_input_listener(function(line)
+    if not line:skip_log() then
+        write_log(line:raw(), INPUT)
+    end
+    return line
+end)