1 files changed, 49 insertions, 1 deletions

diff --git a/src/luarocks/fs/lua.lua b/src/luarocks/fs/lua.lua
index 0e11520b..f3d75b44 100644
--- a/src/luarocks/fs/lua.lua
+++ b/src/luarocks/fs/lua.lua
@@ -496,6 +496,54 @@ end
 
 if socket_ok then
 
+
+local ltn12 = require("ltn12")
+
+--- Download a remote file.
+-- @param url string: URL to be fetched.
+-- @param filename string or nil: this function attempts to detect the
+-- resulting local filename of the remote file as the basename of the URL;
+-- if that is not correct (due to a redirection, for example), the local
+-- filename can be given explicitly as this second argument.
+-- @return boolean: true on success, false on failure.
+function download(url, filename)
+   assert(type(url) == "string")
+   assert(type(filename) == "string" or not filename)
+
+   filename = dir.path(fs.current_dir(), filename or dir.base_name(url))
+   
+   local content, err
+   if util.starts_with(url, "http:") then
+      local proxy = cfg.proxy
+      local url_arg, proxy_result
+      if proxy then
+         proxy_result = {}
+         url_arg = { url = url, proxy = proxy, sink = ltn12.sink.table(proxy_result) }
+      else
+         url_arg = url
+      end
+      local res, status, headers, line = http.request(url_arg)
+      if not res then
+         err = status
+      elseif status ~= 200 then
+         err = line
+      else
+         if proxy_result then res = table.concat(proxy_result) end
+         content = res
+      end
+   elseif util.starts_with(url, "ftp:") then
+      content, err = ftp.get(url)
+   end
+   if not content then
+      return false, "Failed downloading: " .. err
+   end
+   local file = io.open(filename, "wb")
+   if not file then return false end
+   file:write(content)
+   file:close()
+   return true
+end
+
 --- Download a remote file.
 -- @param url string: URL to be fetched.
 -- @param filename string or nil: this function attempts to detect the
@@ -532,8 +580,8 @@ function download(url, filename)
    return true
 end
 
-end
 
+end
 ---------------------------------------------------------------------
 -- MD5 functions
 ---------------------------------------------------------------------