IRKit用のコマンドをcurlで簡単作成

# curl の --libcurl オプションを使う

## 前提
* 参考 [curl コマンドでWEBリクエストするC言語のソースを自動生成 - それマグで！](http://takuya-1st.hatenablog.jp/entry/2015/06/25/172521 "curl コマンドでWEBリクエストするC言語のソースを自動生成 - それマグで！")
* IRKitのIPは192.168.1.1
* 以下の様な電源ボタン相当のjsonファイル ./power.json があるとする

```json
{"format":"raw","freq":38,"data":[6881,3341,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,2537,904,65535,0,65535,0,16832,6881,3341,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,935,2451,904,2451,904,2451,904,2451,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,2537,904,65535,0,65535,0,16832,6881,3341,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,2537,904]}
```

## power.c を生成

```bash
curl -i "http://192.168.1.1/messages" -d "$(cat ./power.json)" --libcurl power.c
```

## gccでコンパイル

```c
gcc power.c -o power -lcurl
```

## 実行してみる

```c
./power
```

実行時の出力がうざいときは curl -i オプションをなくせばよい

# なお生成されたpower.cは以下の様な形

```c
/********* Sample code generated by the curl command line tool **********
 * All curl_easy_setopt() options are documented at:
 * http://curl.haxx.se/libcurl/c/curl_easy_setopt.html
 ************************************************************************/
#include <curl/curl.h>

int main(int argc, char *argv[])
{
  CURLcode ret;
  CURL *hnd;

  hnd = curl_easy_init();
  curl_easy_setopt(hnd, CURLOPT_URL, "http://192.168.1.1/messages");
  curl_easy_setopt(hnd, CURLOPT_NOPROGRESS, 1L);
  curl_easy_setopt(hnd, CURLOPT_HEADER, 1L);
  curl_easy_setopt(hnd, CURLOPT_POSTFIELDS, "{\"format\":\"raw\",\"freq\":38,\"data\":[6881,3341,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,2537,904,65535,0,65535,0,16832,6881,3341,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,935,2451,904,2451,904,2451,904,2451,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,2537,904,65535,0,65535,0,16832,6881,3341,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,815,904,2537,904,815,904,2537,904,2537,904,2537,904,2537,904,815,904,2537,904]}");
  curl_easy_setopt(hnd, CURLOPT_POSTFIELDSIZE_LARGE, (curl_off_t)1315);
  curl_easy_setopt(hnd, CURLOPT_USERAGENT, "curl/7.37.1");
  curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
  curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);

  /* Here is a list of options the curl code used that cannot get generated
     as source easily. You may select to either not use them or implement
     them yourself.

  CURLOPT_WRITEDATA set to a objectpointer
  CURLOPT_WRITEFUNCTION set to a functionpointer
  CURLOPT_READDATA set to a objectpointer
  CURLOPT_READFUNCTION set to a functionpointer
  CURLOPT_SEEKDATA set to a objectpointer
  CURLOPT_SEEKFUNCTION set to a functionpointer
  CURLOPT_ERRORBUFFER set to a objectpointer
  CURLOPT_STDERR set to a objectpointer
  CURLOPT_HEADERFUNCTION set to a functionpointer
  CURLOPT_HEADERDATA set to a objectpointer

  */

  ret = curl_easy_perform(hnd);

  curl_easy_cleanup(hnd);
  hnd = NULL;

  return (int)ret;
}
/**** End of sample code ****/
```