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{
    "adformat": null,
    "afmt": "251",
    "at": "2_3",
    "c": "WEB",
    "cbr": "Chrome",
    "cbrver": "48.0.2564.103",
    "cgr": true,
    "cl": "114833142",
    "cmt": "3639.449",

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Problems & Solutions for Interaction Between C and Go

At Vimeo, on the transcoding team, we work a lot with Go, and a lot with C, for various tasks such as media ingest. This means we use CGO quite extensively, and consequently, have run into bits that are perhaps not very well documented, if at all. Below is my effort to document some of the problems we've run into, and how we fixed or worked around them.

Many of these are obviously wrong in retrospect, but hindsight is 20/20, and these problems do exist in many codebases currently.

Some are definitely ugly, and I much welcome better solutions! Tweet me at @daemon404 if you have any, or have your own CGO story/tips, please! I'd love to learn of them.

Table of Contents

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      source      The source IP address is hashed and divided by the total
                  weight of the running servers to designate which server will
                  receive the request. This ensures that the same client IP
                  address will always reach the same server as long as no
                  server goes down or up. If the hash result changes due to the
                  number of running servers changing, many clients will be
                  directed to a different server. This algorithm is generally
                  used in TCP mode where no cookie may be inserted. It may also
                  be used on the Internet to provide a best-effort stickiness
                  to clients which refuse session cookies. This algorithm is

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/*
 * Qualys test program to check for presence of GHOST vulnerability
 * For more info: http://www.openwall.com/lists/oss-security/2015/01/27/9
 */
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

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{"app":"iMovie(2669)","state":"upload_complete","note":"invalid ticket","ticket":"92a60c5733a8c0ff32edd3d5a17cc94f","found":true,"enabled":1,"ts":1400732418,"ip":"70.76.92.117","hn":"10.90.128.53"}
{"app":"iMovie(2669)","state":"upload_complete","note":"invalid ticket","ticket":"62cdd3bbe0d4cea76381897821a1de74","found":true,"enabled":1,"ts":1400745251,"ip":"68.65.32.68","hn":"10.90.128.51"}
{"app":"Final Cut Pro(9735)","state":"upload_complete","note":"invalid ticket","ticket":"3fccb716ae1bc1c997319d8a0aefdcae","found":true,"enabled":1,"ts":1400763479,"ip":"99.39.114.252","hn":"10.90.128.52"}

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vcl_recv {
    #Extrac query param token
    set resp.http.token = regsub(req.url, "^.*(\?|&)token=([^&]*)(&{0,1}.*|$)", "\2");
}

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http://play.golang.org/p/Olj-v2jBeu

php implementation that works on both 32bit and 64bit

$hash_key = "pwnd";
$to_hash = "Naren";
$buf = str_split($hash_key.$to_hash);
$hash = 2166136261; #offset32
foreach ($buf as $chr)

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Upload Client

HEAD /files/24e533e02ec3bc40c387f1a0e460e216 HTTP/1.1
Host: tus.example.org
Entity-Receive: available

Response:

HTTP/1.1 200 Ok