Curl doesn't redirect properly for some facebook profile IDs - facebook

Question

I'm trying to hack together a bit of code (c++) that returns a current facebook display name for a given user ID. The code works perfectly fine for most IDs but for some IDs curl returns a 404 even though the same URL opens fine in a browser. Here's the bit of code related to curl.
int main(int argc, char const *argv[]) {
CURL* curl;
char userAgent[] = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US;
rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13";
curl_global_init(CURL_GLOBAL_ALL);
curl = curl_easy_init();
string fbID = argv[1];
string searchTerm = "https://www.facebook.com/profile.php?id=" + fbID;
cout << "searching for: " << searchTerm << endl;
if(!curl)
return 0;
else{
curl_easy_setopt(curl, CURLOPT_USERAGENT, userAgent);
curl_easy_setopt(curl, CURLOPT_URL, searchTerm.c_str());
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, &writeCallback);
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, true);
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); //tell curl to output
its progress
}
//scan the retrieved data for the name...
}
size_t writeCallback(char* buf, size_t size, size_t nmemb, void* up)
{ //i copied this function
for (int c = 0; c<size*nmemb; c++)
{
data.push_back(buf[c]);
}
return size*nmemb;
}
I don't exactly know where to look because it works for most ids but for example "1094145063" returns a 404 even though https://www.facebook.com/profile.php?id=1094145063
opens fine in a browser. (1331601579 for example works fine with my code)
I can't spot the difference between the sites.
It does however make a redirect to https://www.facebook.com/"username" which works fine once CURLOPT_FOLLOWLOCATION is set, but only on some sites. Here's the message curl outputs.
* Hostname was NOT found in DNS cache
* Trying 31.13.84.36...
* Connected to www.facebook.com (31.13.84.36) port 443 (#0)
* found 174 certificates in /etc/ssl/certs/ca-certificates.crt
* server certificate verification OK
* common name: *.facebook.com (matched)
* server certificate expiration date OK
* server certificate activation date OK
* certificate public key: EC
* certificate version: #3
* subject: C=US,ST=California,L=Menlo Park,O=Facebook\, Inc.,CN=*.facebook.com
* start date: Fri, 09 Dec 2016 00:00:00 GMT
* expire date: Thu, 25 Jan 2018 12:00:00 GMT
* issuer: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert SHA2 High Assurance Server CA
* compression: NULL
* cipher: AES-128-GCM
* MAC: AEAD
> GET /profile.php?id=1094145063 HTTP/1.1
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13
Host: www.facebook.com
Accept: */*
HTTP/1.1 404 Not Found
X-XSS-Protection: 0
public-key-pins-report-only: max-age=500; pin-sha256="WoiWRyIOVNa9ihaBciRSC7XHjliYS9VwUGOIud4PB18="; pin-sha256="r/mIkG3eEpVdm+u/ko/cwxzOMo1bk4TyHIlByibiA5E="; pin-sha256="q4PO2G2cbkZhZ82+JgmRUyGMoAeozA+BSXVXQWB8XWQ="; report-uri="http://reports.fb.com/hpkp/"
Pragma: no-cache
content-security-policy: default-src * data: blob:;script-src *.facebook.com *.fbcdn.net *.facebook.net *.google-analytics.com *.virtualearth.net *.google.com 127.0.0.1:* *.spotilocal.com:* 'unsafe-inline' 'unsafe-eval' fbstatic-a.akamaihd.net fbcdn-static-b-a.akamaihd.net *.atlassolutions.com blob: data: 'self';style-src data: blob: 'unsafe-inline' *;connect-src *.facebook.com *.fbcdn.net *.facebook.net *.spotilocal.com:* *.akamaihd.net wss://*.facebook.com:* https://fb.scanandcleanlocal.com:* *.atlassolutions.com attachment.fbsbx.com ws://localhost:* blob: *.cdninstagram.com 'self';
Cache-Control: private, no-cache, no-store, must-revalidate
Strict-Transport-Security: max-age=15552000; preload
X-Content-Type-Options: nosniff
Expires: Sat, 01 Jan 2000 00:00:00 GMT
Vary: Accept-Encoding
Content-Type: text/html; charset=UTF-8
X-FB-Debug: pA9SSTdWWx2a66QeP7Je/4ik/2a+/ZL/m/nckHKf+KoEZLloClzu+qMDzyE/B8M1PRDl4SdS19C9vIIl7f43mA==
Date: Tue, 06 Jun 2017 18:25:15 GMT
Transfer-Encoding: chunked
Connection: keep-alive
* Connection #0 to host www.facebook.com left intact
Any help would be appreciated.
(my first SO post so please don't be too harsh if i did something dumb)