From ff2bc5d0931d4a460d4d74183b6f9dd9394c40a0 Mon Sep 17 00:00:00 2001
From: clsr <clsr@clsr.net>
Date: Wed, 22 Mar 2017 21:07:10 +0100
Subject: Initial commit

---
 modules/sed.bash | 189 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 189 insertions(+)
 create mode 100644 modules/sed.bash

(limited to 'modules/sed.bash')

diff --git a/modules/sed.bash b/modules/sed.bash
new file mode 100644
index 0000000..b75a252
--- /dev/null
+++ b/modules/sed.bash
@@ -0,0 +1,189 @@
+# modules/sed.bash
+#
+# Provides sedbot.
+#
+# Settings:
+# SED_TIMEOUT_BIN: path to the timeout script¹; optional to prevent regex DoS
+# SED_TIMEOUT_MEM: maximum amount of memory (in kilobytes) a sed process may use
+#
+# ¹: https://github.com/pshved/timeout
+
+
+if [ -z "$IRCBOT_MODULE" ]; then
+	printf "error: %s is a module for ircbot.bash and should not be run separately\n" "$0"
+	exit 1
+fi
+
+declare -g -A sed_messages
+
+# seds a previous message if instucted to
+on_privmsg() { # args: $1 - source, $2 - channel/target, $3 - message
+	local where nick msg
+	local targetednick origmsg origkey
+	local key target fromnick regexed ctcp
+
+	where="$2"
+	nick="$(parse_source_nick "$1")"
+	msg="$3"
+	if [[ $where == "$IRCBOT_NICK" ]]; then
+		where="$nick"
+	fi
+
+	# targeted means the message was ``<user1> user2: s/foo/bar/'' (targets user2's last message)
+	origmsg="$msg"
+	origkey="$where $nick"
+	if targetednick="$(parse_targeted_nick "$msg")"; then
+		nick="$targetednick"
+		msg="$(parse_targeted_msg "$msg")"
+	fi
+
+
+	key="$where $nick"
+	target="${sed_messages[$key]:-}"
+
+	# handle regexing CTCP ACTIONs properly
+	ctcp="$(parse_ctcp_command "$target")" || true
+	if [[ $ctcp == ACTION ]]; then
+		target="$(parse_ctcp_message "$target")"
+		fromnick="$(printf "\\x02* %s\\x02" "$nick")"
+	else
+		fromnick="<$nick>"
+	fi
+
+	if regexed="$(sed_replace "$msg" "$target")"; then # if a replacement was done, send it
+		sendmsg PRIVMSG "$where" "$fromnick $regexed"
+	else # otherwise, store the triggering message
+		sed_messages[$origkey]="$origmsg"
+	fi
+}
+
+sed_replace() { # args: $1 - sed s expression, $2 - text to regex
+	local msg target
+	local l pos i p del
+	local regexps ok t target
+
+	msg="$1"
+	target="$2"
+
+	del="${msg:1:1}"
+	if [[ -z $del ]] || [[ $(indexof '/|,!:' "$del") -lt 0 ]]; then
+		return 1
+	fi
+
+	# TODO: rewrite so that only one expression is tokenized at once (allows different delimiters)
+
+	# tokenize
+	l=()
+	pos="$(indexof "$msg" "$del")"
+	while ((pos >= 0)); do
+		i=0
+		((p=pos-i-1))
+		while ((p >= 0)) && [[ ${msg:$p:1} == '\' ]]; do # count \ characters
+			((i++))
+			((p=pos-i-1))
+		done
+		if ((i%2 == 0)); then
+			l+=("${msg:0:$pos}")
+			((p=pos+1))
+			msg="${msg:$p}"
+			pos=0
+		else
+			((pos++))
+		fi
+		p="$(indexof "${msg:$pos}" "$del")"
+		if ((p >= 0)); then
+			((pos+=p))
+		else
+			pos=$p
+		fi
+	done
+	l+=("$msg")
+
+	# l is now an array of the expr separated by unescaped delimiters
+
+	i=0
+	regexps=()
+	ok=1
+
+	# s/expr1/repl1/opts1 s/expr2/repl2/opts2 s/expr3/repl3
+	while ((i < ${#l[@]})); do
+		# begins with s
+		if [ "${l[$i]}" != "s" ]; then
+			break
+		fi
+		((i++))
+
+		# expr
+		if ((i >= ${#l[@]})); then
+			break
+		fi
+		exp="${l[$i]}"
+		((i++))
+
+		# repl
+		if ((i >= ${#l[@]})); then
+			break
+		fi
+		repl="${l[$i]}"
+		((i++))
+
+		# opts
+		opts=''
+		if ((i < ${#l[@]})); then
+			opts="${l[$i]}"
+			p=0
+			while ((p < ${#opts})); do
+				c="${opts:$p:1}"
+				if ! [[ $c =~ ^[ig0-9]$ ]]; then # allowed opts are 0-9, i and g
+					ok=0
+					break
+				fi
+				((p++))
+			done
+			if ! ((ok)); then
+				# multiple regexps per line
+				if [[ "${opts:$p:1}" == ' ' || "${opts:$p:1}" == ';' ]]; then # expression separators are space and ;
+					p1=$p
+					while ((p < ${#opts})); do
+						if [[ "${opts:$p:1}" != ' ' && "${opts:$p:1}" != ';' ]]; then
+							break
+						fi
+						p=$((p+1))
+					done
+					l[$i]="${opts:$p}"
+					opts="${opts:0:$p1}"
+					ok=1
+				else
+					break
+				fi
+			fi
+		fi
+
+		if ((ok)); then
+			regexps+=("s$del$exp$del$repl$del$opts")
+		fi
+	done
+
+
+	if ! ((ok)) || ((${#regexps[@]} == 0)); then
+		return 1
+	fi
+
+	t="$target"
+	for re in "${regexps[@]}"; do
+		if [[ -n ${SED_TIMEOUT_BIN:-} ]]; then
+			target="$("$SED_TIMEOUT_BIN" -m "$SED_TIMEOUT_MEM" sed -e "$re" <<< "$target")"
+		else
+			target="$(sed -e "$re" <<< "$target")"
+		fi
+	done
+	target="$(trimrn <<< "$target")"
+	verbose "sed '%s' <<< '%s' >>> '%s'" "$1" "$2" "$target"
+	if [[ $target != "$t" ]]; then
+		if [[ -n $target ]]; then
+			trimrn <<< "$target"
+			return 0
+		fi
+	fi
+	return 1
+}
-- 
cgit