# Lua binding to [libcurl](http://curl.haxx.se/libcurl)
[](https://travis-ci.org/Lua-cURL/Lua-cURLv3)
[](https://ci.appveyor.com/project/moteus/lua-curlv3)
[](https://coveralls.io/r/Lua-cURL/Lua-cURLv3?branch=master)
[](LICENSE)
## Status
This module include three layer
1. `lcurl` module provide low level pure C binding to libcurl.
Almost ready and needs tests. I have no plans to change this API.
2. `cURL` module provide compatibility for Lua-cURLv2 API.
Almost ready and needs tests.
3. `cURL` module provide new high level API.
In fact for now it provide `lcurl` API directly and needed to redesign.
## Documentation
[lcurl API](http://lua-curl.github.io/lcurl/modules/lcurl.html)
[Lua-cURLv2 API](http://lua-curl.github.io)
[Lua-cURLv3 API](http://lua-curl.github.io/lcurl/modules/cURL.html)
##
Original Lua-cURLv2 binding has several problems:
* it can not return error codes but just raise Lua errors (Fixed. use `cURL.safe` module)
* it raise Lua error from callback that may result resource leak in libcurl (Fixed.)
* it does not provide building multipart/formdata explicitly (Fixed.)
* it has memory leak when send multipart/formdata (Fixed.)
* it does not save string for curl options that may result crush in libcurl (Fixed.)
* there no way to get result for operations in multi interface (e.g. if one of easy operation fail you can not get result code/error message) (Fixed. But it does not very handy interface.)
* you can not use your own callback function to perform operation with multi interface (Could not be fixed without changing API.)
* you can not pass your context to callback functions (Could not be fixed without changing API.)
## Installation
Using LuaRocks:
```
luarocks install Lua-cURL
```
Install current master:
```
luarocks install Lua-cURL --server=https://luarocks.org/dev
```
## List of incompatibility with original [Lua-cURLv2](https://github.com/Lua-cURL/Lua-cURLv2)
* objects are tables
* multi:perform() also returns ("done",code), ("error",error) and ("response",code) records
* writer callback does not recv string len (just string itself)
* on Lua > 5.2 errors are objects but not strings
## Usage
```Lua
-- HTTP Get
curl.easy{
url = 'http://httpbin.org/get',
httpheader = {
"X-Test-Header1: Header-Data1",
"X-Test-Header2: Header-Data2",
},
writefunction = io.stderr -- use io.stderr:write()
}
:perform()
:close()
```
```Lua
-- HTTP Post
curl.easy()
:setopt_url('http://posttestserver.com/post.php')
:setopt_writefunction(io.write)
:setopt_httppost(curl.form() -- Lua-cURL guarantee that form will be alive
:add_content("test_content", "some data", {
"MyHeader: SomeValue"
})
:add_buffer("test_file", "filename", "text data", "text/plain", {
"Description: my file description"
})
:add_file("test_file2", "BuildLog.htm", "application/octet-stream", {
"Description: my file description"
})
)
:perform()
:close()
```
```Lua
-- FTP Upload
local function get_bin_by(str,n)
local pos = 1 - n
return function()
pos = pos + n
return (str:sub(pos,pos+n-1))
end
end
curl.easy()
:setopt_url("ftp://moteus:123456@127.0.0.1/test.dat")
:setopt_upload(true)
:setopt_readfunction(
get_bin_by(("0123456789"):rep(4), 9)
)
:perform()
:close()
```
```Lua
-- Multi FTP Upload
-- We get error E_LOGIN_DENIED for this operation
e1 = curl.easy{url = "ftp://moteus:999999@127.0.0.1/test1.dat", upload = true}
:setopt_readfunction(
function(t) return table.remove(t) end, {"1111", "2222"}
)
e2 = curl.easy{url = "ftp://moteus:123456@127.0.0.1/test2.dat", upload = true}
:setopt_readfunction(get_bin_by(("e"):rep(1000), 5))
m = curl.multi()
m:add_handle(e1)
m:add_handle(e2)
while m:perform() > 0 do m:wait() end
while true do
h, ok, err = m:info_read()
if h == 0 then break end
if h == e1 then
assert(ok == nil)
assert(err:name() == "LOGIN_DENIED")
assert(err:no() == curl.E_LOGIN_DENIED)
end
if h == e2 then
assert(ok == true)
end
end
```