Add Lua 5.2 compatibility.

README.md

@@ -20,7 +20,7 @@ otouto (including all plugins and documentation) is free software; you are free
 ## Setup
 To get your bot running as soon as possible, see [Quick start](#quick-start).
 
-otouto uses Lua 5.3 and the following Lua libraries: luasocket, luasec, multipart-post, dkjson, and lpeg. It is recommended you install these with Luarocks. This can be done easily on Ubuntu 16.04 and later with the `install-dependencies.sh` script.
+otouto uses Lua (5.3 is recommended) and the following Lua libraries: luasocket, luasec, multipart-post, dkjson, and lpeg. If you are using Lua 5.2, luautf8 is also required. It is recommended you install these with Luarocks. This can be done easily on Ubuntu with the `install-dependencies.sh` script.
 
 To get started, clone the repository and set the following values in `config.lua`:
 
@@ -29,7 +29,7 @@ To get started, clone the repository and set the following values in `config.lua
 
 Some plugins are not enabled by default. If you wish to enable them, add their names (sans file extension) to the `plugins` table in the configuration file.
 
-When you are ready to start the bot, run the `launch.sh` script. This script will automatically restart the bot five seconds after being stopped. If this behavior is undesired, start the bot manually with `lua5.3 main.lua`.
+When you are ready to start the bot, run the `launch.sh` script. This script will automatically restart the bot five seconds after being stopped. If this behavior is undesired, start the bot manually with `lua main.lua`.
 
 To stop the bot, send "/halt" through Telegram. You can exit with Ctrl-C (or two Ctrl-C if using `launch.sh`), but this is not recommended as it risks data loss.
 
@@ -38,11 +38,11 @@ Note that certain plugins, such as `translate.lua` and `greetings.lua`, will req
 ### Quick start
 1. Clone the repository.
 `git clone http://otou.to/code otouto`
-2. Install dependencies: Lua 5.3, and the following Lua libs: luasocket, luasec, multipart-post, dkjson, and lpeg.†
+2. Install dependencies: Lua and the following Lua libs: luasocket, luasec, multipart-post, dkjson, and lpeg.†
 3. Add your bot token and Telegram ID to `config.lua`.
 4. Start the bot with `./launch.sh`.
 
-**†** On Ubuntu 16.04, this can be done easily with the `install-dependencies.sh` script.
+**†** On Ubuntu, this can be done easily with the `install-dependencies.sh` script.
 
 ## Configuration
 otouto is configured in the `config.lua` file. It is the single point of configuration for the bot, and contains any necessary user-specific variables, such as API keys, custom error messages, and enabled plugins.

install-dependencies.sh

@@ -1,31 +1,35 @@
-# This script will attempt to install Lua 5.3, Luarocks (pointed at 5.3), and
-# the rocks necssary to run otouto. This script targets Ubuntu 16.04; it will
-# probably not work on earlier versions of Ubuntu.
+# Install Lua, Luarocks, and otouto dependencies. Works in Ubuntu, maybe Debian.
+# Installs Lua 5.3 if Ubuntu 16.04. Otherwise, 5.2.
 
 #!/bin/sh
 
-echo "This script is intended for Ubuntu 16.04 and later. It will not work in"
-echo "14.04 or earlier."
+if [ $(lsb_release -r | cut -f 2) == "16.04" ]; then
+    luaver="5.3"
+    rocklist="luasocket luasec multipart-post lpeg dkjson"
+else
+    luaver="5.2"
+    rocklist="luasocket luasec multipart-post lpeg dkjson serpent"
+fi
+
+echo "This script is intended for Ubuntu. It may work in Debian."
 echo "This script will request root privileges to install the following packages:"
-echo "lua5.3 liblua5.3-dev git libssl-dev fortune-mod fortunes unzip"
+echo "lua$luaver liblua$luaver-dev git libssl-dev fortune-mod fortunes unzip make"
 echo "It will also request root privileges to install Luarocks to to /usr/local/"
 echo "along with the following rocks:"
-echo "luasocket luasec multipart-post lpeg dkjson"
+echo $rocklist
 echo "Press enter to continue. Use Ctrl-C to exit."
 read
 
 sudo apt-get update
-sudo apt-get install -y lua5.3 liblua5.3-dev git libssl-dev fortune-mod fortunes unzip
+sudo apt-get install -y lua$luaver liblua$luaver-dev git libssl-dev fortune-mod fortunes unzip make
 git clone http://github.com/keplerproject/luarocks
 cd luarocks
-./configure --lua-version=5.3 --versioned-rocks-dir --lua-suffix=5.3
+./configure --lua-version=$luaver --versioned-rocks-dir --lua-suffix=$luaver
 make build
 sudo make install
-sudo luarocks-5.3 install luasocket
-sudo luarocks-5.3 install luasec
-sudo luarocks-5.3 install multipart-post
-sudo luarocks-5.3 install lpeg
-sudo luarocks-5.3 install dkjson
+for rock in $rocklist; do
+    sudo luarocks-$luaver install $rock
+done
 sudo -k
 cd ..
 

launch.sh

@@ -1,5 +1,8 @@
-# Launch otouto, after checking for Lua 5.3.
-# Restart otouto five seconds after halted.
+# Run otouto in Lua 5.3, if available.
+# (Specifying lua5.3 because "lua" is not linked to it in Ubuntu 16.04.)
+# Otherwise, use any generic installed Lua.
+# If none, give an error and a friendly suggestion.
+# If Lua was found, restart otouto five seconds after halting each time.
 
 #!/bin/sh
 
@@ -10,7 +13,13 @@ if type lua5.3 >/dev/null 2>/dev/null; then
         echo "otouto has stopped. ^C to exit."
         sleep 5s
     done
+elif type lua >/dev/null 2>/dev/null; then
+    while true; do
+        lua main.lua
+        echo "otouto has stopped. ^C to exit."
+        sleep 5s
+    done
 else
-    echo "Lua 5.3 was not found."
-    echo "If you're on Ubuntu 16.04+, try running ./install-dependencies.sh."
+    echo "Lua not found."
+    echo "If you're on Ubuntu, try running ./install-dependencies.sh."
 fi

otouto/plugins/luarun.lua

@@ -17,6 +17,12 @@ function luarun:init(config)
             return JSON.encode(t, {indent=true})
         end
     end
+    -- Lua 5.2 compatibility.
+    -- "loadstring" was renamed "load" in 5.3.
+    luarun.loadstring = load or loadstring
+    luarun.err_msg = function(x)
+        return 'Error:\n' .. tostring(x)
+    end
 end
 
 function luarun:action(msg, config)
@@ -35,8 +41,8 @@ function luarun:action(msg, config)
         input = 'return ' .. input
     end
 
-    local output, success =
-        load("local bot = require('otouto.bot')\n\z
+    local output, success = luarun.loadstring(
+        "local bot = require('otouto.bot')\n\z
         local bindings = require('otouto.bindings')\n\z
         local utilities = require('otouto.utilities')\n\z
         local drua = require('otouto.drua-tg')\n\z
@@ -44,16 +50,13 @@ function luarun:action(msg, config)
         local URL = require('socket.url')\n\z
         local HTTP = require('socket.http')\n\z
         local HTTPS = require('ssl.https')\n\z
-        return function (self, msg, config)\n" .. input .. "\nend")
-
-    local function err_msg(x)
-        return "Error:\n" .. tostring(x)
-    end
+        return function (self, msg, config)\n" .. input .. "\nend"
+    )
 
     if output == nil then
         output = success
     else
-        success, output = xpcall(output(), err_msg, self, msg, config)
+        success, output = xpcall(output(), luarun.err_msg, self, msg, config)
     end
 
     if output == nil then

otouto/utilities.lua

@@ -26,6 +26,9 @@ local HTTPS = require('ssl.https')
 local URL = require('socket.url')
 local JSON = require('dkjson')
 local bindings = require('otouto.bindings')
+ -- Lua 5.2 compatibility.
+ -- If no built-in utf8 is available, load the library.
+local utf8 = utf8 or require('lua-utf8')
 
  -- For the sake of ease to new contributors and familiarity to old contributors,
  -- we'll provide a couple of aliases to real bindings here.
@@ -324,8 +327,7 @@ end
  -- Converts a gross string back into proper UTF-8.
  -- Useful for fixing improper encoding caused by bad JSON escaping.
 function utilities.fix_utf8(str)
-	return string.char(utf8.codepoint(str, 1, -1))
+    return string.char(utf8.codepoint(str, 1, -1))
 end
 
-
 return utilities

tg-install.sh

@@ -2,8 +2,7 @@
 
 #!/bin/sh
 
-echo "This script is intended for Ubuntu 16.04 and later. It will probably work on"
-echo "14.04 or 12.04 as well as Debian, but this is not guaranteed."
+echo "This script is intended for Ubuntu. It has been tested on 16.04 and 14.04."
 echo "This script will request root privileges to install the following packages:"
 echo "git libreadline-dev libssl-dev libevent-dev make"
 echo "Press enter to continue. Use Ctrl-C to exit."