Import code.

.gitignore

@@ -0,0 +1,2 @@
+/creds
+/server

Makefile

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+.PHONY: install
+
+install:
+	if ! /bin/getent group evalr >/dev/null; then \
+		/sbin/groupadd --system evalr; \
+	fi
+
+	if ! /bin/getent passwd evalr >/dev/null; then \
+		/sbin/useradd --system --gid evalr --commend 'evalr user' --shell /sbin/nologin --home-dir /var/lib/evalr --create-home evalr; \
+	fi
+
+	cp main.awk main.sh playground.sh /var/lib/evalr/
+	chown evalr:evalr /var/lib/evalr/{main.awk,main.sh,playground.sh}
+
+	mkdir -p /etc/systemd/system/
+	cp evalr.service /etc/systemd/system/
+	chown root:root /etc/systemd/system/evalr.service
+	systemctl daemon-reload

README.md

@@ -1,6 +1,40 @@
 This is an IRC bot that evaluates code snippets using <https://play.rust-lang.org> and prints the results.
 
 
+# Dependencies
+
+Required:
+
+- `awk`, specifically `gawk`
+- `jq`
+- `openssl`
+
+Optional:
+
+- `make` - if you use the Makefile to install the services files
+
+
+# Install
+
+```sh
+# Install binaries and systemd service, and create service user.
+sudo make install
+
+# Create creds file. "IRC_PASSWORD" is optional.
+cat <<-EOF
+IRC_SERVER=...
+IRC_NICKNAME=...
+IRC_USERNAME=...
+IRC_PASSWORD=...
+EOF | sudo tee /var/lib/evalr/creds >/dev/null
+sudo chown evalr:evalr /var/lib/evalr/creds
+sudo chmod 0600 /var/lib/evalr/creds
+
+systemctl enable evalr
+systemctl start evalr
+```
+
+
 # License
 
 ```

evalr.service

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+[Unit]
+Description=evalr IRC bot for ##rust@freenode
+
+[Service]
+ExecStart=/var/lib/evalr/main.sh
+WorkingDirectory=~
+Restart=always
+RestartSec=5s
+User=evalr
+Group=evalr
+
+[Install]
+WantedBy=default.target

main.awk

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+BEGIN {
+	write_line(sprintf("NICK %s", IRC_NICKNAME))
+	write_line(sprintf("USER %s 0 * :Bot owned by Arnavion", IRC_USERNAME))
+	if (IRC_PASSWORD != "") {
+		write_line(sprintf("PRIVMSG nickserv :IDENTIFY %s %s", IRC_USERNAME, IRC_PASSWORD))
+	}
+
+	channel_privmsg_regex = sprintf("^:?%s:", IRC_NICKNAME)
+	privmsg_regex = sprintf("^:?%s:", IRC_NICKNAME)
+	highlight_regex = sprintf("^%s:", IRC_NICKNAME)
+}
+
+{
+	gsub(/\r$/, "")
+	read_line()
+}
+
+/^PING\r$/ {
+	write_line("PONG")
+}
+
+/^PING / {
+	write_line(sprintf("PONG %s", $2))
+}
+
+/^[^ ]+ 001 / {
+	if (IRC_PASSWORD == "") {
+		write_line("JOIN ##rust")
+	}
+}
+
+/^:NickServ!NickServ@services\. NOTICE / {
+	if ($3 == IRC_NICKNAME) {
+		message = ""
+		for (i = 4; i <= NF; i++) {
+			message = sprintf("%s%s ", message, $i)
+		}
+		gsub(/^:/, "", message)
+
+		if (message ~ /^You are now identified for /) {
+			write_line("JOIN ##rust")
+		}
+	}
+}
+
+/^[^ ]+ PRIVMSG ##rust / {
+	if ($4 ~ channel_privmsg_regex) {
+		printf "=== Acting on request\n" > "/dev/stderr"
+
+		split(substr($1, 2), nick_parts, "!")
+		nick = nick_parts[1]
+
+		message = ""
+		for (i = 4; i <= NF; i++) {
+			message = sprintf("%s%s ", message, $i)
+		}
+		gsub(channel_privmsg_regex, "", message)
+
+		command = "./playground.sh"
+		printf "%s", message |& command
+		fflush()
+		close(command, "to")
+		while ((command |& getline) > 0) {
+			write_line(sprintf("NOTICE ##rust :%s: %s", nick, $0))
+		}
+		close(command)
+	}
+}
+
+/^[^ ]+ PRIVMSG / {
+	if ($3 == IRC_NICKNAME) {
+		split(substr($1, 2), nick_parts, "!")
+		nick = nick_parts[1]
+
+		message = ""
+		for (i = 4; i <= NF; i++) {
+			message = sprintf("%s%s ", message, $i)
+		}
+		gsub(/^:/, "", message)
+
+		if (substr(message, 1, 1) != "\x01") {
+			printf "=== Acting on request\n" > "/dev/stderr"
+
+			gsub(highlight_regex, "", message)
+
+			command = "./playground.sh"
+			printf "%s", message |& command
+			fflush()
+			close(command, "to")
+			while ((command |& getline) > 0) {
+				write_line(sprintf("PRIVMSG %s :%s", nick, $0))
+			}
+			close(command)
+		}
+	}
+}
+
+function read_line() {
+	printf "<<< %s\n", $0 > "/dev/stderr"
+}
+
+function write_line(line) {
+	printf ">>> %s\n", line > "/dev/stderr"
+	printf "%s\r\n", line
+	fflush()
+}

main.sh

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+#!/bin/bash
+
+set -euo pipefail
+
+. creds
+
+rm -f server
+trap 'rm -f server' EXIT
+mkfifo server
+
+<server awk \
+	-f main.awk \
+	-v "IRC_NICKNAME=$IRC_NICKNAME" \
+	-v "IRC_USERNAME=$IRC_USERNAME" \
+	-v "IRC_PASSWORD=${IRC_PASSWORD:-}" |
+	openssl s_client -connect "$IRC_SERVER" -quiet >server

playground.sh

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+#!/bin/bash
+
+set -euo pipefail
+
+message="$(cat)"
+
+attrs=''
+channel='stable'
+code=''
+mode='debug'
+
+while :; do
+	case "$message" in
+		' '*)
+			message="${message# }"
+			;;
+
+		'--beta'|'--beta '*)
+			channel='beta'
+			message="${message#--beta }"
+			;;
+
+		'--nightly'|'--nightly '*)
+			channel='nightly'
+			message="${message#--nightly }"
+			;;
+
+		'--release'|'--release '*)
+			mode='release'
+			message="${message#--release }"
+			;;
+
+		'#!['*)
+			attr_end="$(expr index "$message" ']')"
+			attrs="$(printf '%s%s\n' "$attrs" "${message:0:$attr_end}")"
+			message="${message:$attr_end}"
+			;;
+
+		*)
+			code="$message"
+			break
+			;;
+	esac
+done
+
+if [ -z "$code" ]; then
+	exit 0
+fi
+
+request_body_base="$(
+	jq -cn \
+		--arg attrs "$attrs" \
+		--arg code "$code" \
+		'{
+			"code": (
+				$attrs +
+				"fn main() { println!(\"{:?}\", {\n\n" +
+				$code +
+				"\n\n}); }"
+			)
+		}'
+)"
+
+if [ -n "${EVALR_TEST:-}" ]; then
+	jq -cn \
+		--argjson request_body_base "$request_body_base" \
+		--arg channel "$channel" \
+		--arg mode "$mode" \
+		'$request_body_base + {
+			"channel": $channel,
+			"mode": $mode
+		}'
+	exit 0
+fi
+
+response="$(
+	jq -cn \
+		--argjson request_body_base "$request_body_base" \
+		--arg channel "$channel" \
+		--arg mode "$mode" \
+		'$request_body_base + {
+			"channel": $channel,
+			"mode": $mode,
+			"edition": "2018",
+			"crateType": "bin",
+			"tests": false,
+			"backtrace": false
+		}' |
+		(
+			curl \
+				--max-time 10 \
+				--silent \
+				-X POST \
+				-H 'user-agent: irc.freenode.net/Arnavion' \
+				-H 'accept: application/json' \
+				-H 'content-type: application/json' \
+				--data-binary @- \
+				'https://play.rust-lang.org/execute' ||
+			:
+		)
+)"
+
+create_gist=0
+if [ -n "$response" ] && (<<< "$response" jq -er '.success' >/dev/null); then
+	output="$(<<< "$response" jq -r '.stdout')"
+else
+	output="$( (<<< "$response" jq -r '.stderr' | grep '^error') || printf 'unknown error')"
+	create_gist=1
+fi
+
+irc_output="$(<<< "$output" head -n 1 | head -c 64)"
+if [ "$irc_output" != "$output" ]; then
+	create_gist=1
+fi
+
+if (( create_gist == 1 )); then
+	printf '%s ...\n' "$irc_output"
+
+	<<< "$request_body_base" curl \
+		--max-time 10 \
+		--silent \
+		-H 'user-agent: irc.freenode.net/Arnavion' \
+		-H 'accept: application/json' \
+		-H 'content-type: application/json' \
+		--data-binary @- \
+		'https://play.rust-lang.org/meta/gist/' |
+		jq -r '"https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=\(.id)"'
+else
+	printf '%s\n' "$irc_output"
+fi
+
+sleep 2