contrib/casemap-logs.sh: new utility script

Previous soju versions were storing log without converting the channel
and nick names to their canonical lower-case representation. This could
result in two log directories for the same channel/nick.

This script fixes old log dirs.

contrib/casemap-logs.sh

@@ -0,0 +1,42 @@
+#!/bin/sh -eu
+
+# Converts a log dir to its case-mapped form.
+#
+# soju needs to be stopped for this script to work properly. The script may
+# re-order messages that happened within the same second interval if merging
+# two daily log files is necessary.
+#
+# usage: casemap-logs.sh <directory>
+
+root="$1"
+
+for net_dir in "$root"/*/*; do
+	for chan in $(ls "$net_dir"); do
+		cm_chan="$(echo $chan | tr '[:upper:]' '[:lower:]')"
+		if [ "$chan" = "$cm_chan" ]; then
+			continue
+		fi
+
+		if ! [ -d "$net_dir/$cm_chan" ]; then
+			echo >&2 "Moving case-mapped channel dir: '$net_dir/$chan' -> '$cm_chan'"
+			mv "$net_dir/$chan" "$net_dir/$cm_chan"
+			continue
+		fi
+
+		echo "Merging case-mapped channel dir: '$net_dir/$chan' -> '$cm_chan'"
+		for day in $(ls "$net_dir/$chan"); do
+			if ! [ -e "$net_dir/$cm_chan/$day" ]; then
+				echo >&2 "  Moving log file: '$day'"
+				mv "$net_dir/$chan/$day" "$net_dir/$cm_chan/$day"
+				continue
+			fi
+
+			echo >&2 "  Merging log file: '$day'"
+			sort "$net_dir/$chan/$day" "$net_dir/$cm_chan/$day" >"$net_dir/$cm_chan/$day.new"
+			mv "$net_dir/$cm_chan/$day.new" "$net_dir/$cm_chan/$day"
+			rm "$net_dir/$chan/$day"
+		done
+
+		rmdir "$net_dir/$chan"
+	done
+done