Merge pull request dan200#536 from Luca0208/ComputerCraft/master

Make wget automatically determine the file name.

Author: SquidDev

src/main/resources/assets/computercraft/lua/rom/help/wget.txt

@@ -1,5 +1,7 @@
 wget is a program for downloading files from the internet. This is useful for downloading programs created by other players.
+If no filename is specified wget will try to determine the filename from the URL by stripping any anchors, parameters and trailing slashes and then taking everything remaining after the last slash.
 The HTTP API must be enabled in ComputerCraft.cfg to use this program.
-
 ex:
 "wget http://pastebin.com/raw/CxaWmPrX test" will download the file from the URL http://pastebin.com/raw/CxaWmPrX, and save it as "test".
+"wget http://example.org/test.lua/?foo=bar#qzu" will download the file from the URL http://example.org/test.lua/?foo=bar#qzu and save it as "test.lua"
+"wget http://example.org/" will download the file from the URL http://example.org and save it as "example.org"

src/main/resources/assets/computercraft/lua/rom/programs/http/wget.lua

@@ -1,11 +1,11 @@
 
 local function printUsage()
     print( "Usage:" )
-    print( "wget <url> <filename>" )
+    print( "wget <url> [filename]" )
 end
 
 local tArgs = { ... }
-if #tArgs < 2 then
+if #tArgs < 1 then
     printUsage()
     return
 end
@@ -15,19 +15,15 @@ if not http then
     printError( "Set http_enable to true in ComputerCraft.cfg" )
     return
 end
- 
+
+local function getFilename( sUrl )
+    sUrl = sUrl:gsub( "[#?].*" , "" ):gsub( "/+$" , "" )
+    return sUrl:match( "/([^/]+)$" )
+end
+
 local function get( sUrl )
     write( "Connecting to " .. sUrl .. "... " )
 
-    local ok, err = http.checkURL( sUrl )
-    if not ok then
-        print( "Failed." )
-        if err then
-            printError( err )
-        end
-        return nil
-    end
-
     local response = http.get( sUrl , nil , true )
     if not response then
         print( "Failed." )
@@ -40,10 +36,18 @@ local function get( sUrl )
     response.close()
     return sResponse
 end
- 
+
 -- Determine file to download
 local sUrl = tArgs[1]
-local sFile = tArgs[2]
+
+--Check if the URL is valid
+local ok, err = http.checkURL( sUrl )
+if not ok then
+    printError( err or "Invalid URL." )
+    return
+end
+
+local sFile = tArgs[2] or getFilename( sUrl )
 local sPath = shell.resolve( sFile )
 if fs.exists( sPath ) then
     print( "File already exists" )