CURLOPT_DI...AME_IN_URL(3)

💅 CURLOPT_DI...AME_IN_URL(3) — like, the whole glow-up

okay bestie, welcome to the Library Functions Manual corner of the curl universe 🎀 the page name is a little truncated up top (CURLOPT_DI...AME_IN_URL(3)) but don't let that jump-scare you, it's just CURLOPT_DISALLOW_USERNAME_IN_URL being too iconic for the header line. sit down, grab a strawberry drink 🍓, and let's get into it.

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✨ NAME ✨

CURLOPT_DISALLOW_USERNAME_IN_URL — literally just: disallow specifying username in the URL. that's the whole vibe check 🚫

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🌸 SYNOPSIS 🌸

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DISALLOW_USERNAME_IN_URL,
                          long disallow);

yes girl, three arguments, and the third one is a long named disallow — the naming ate, honestly 👑

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🦋 DESCRIPTION 🦋

so here's the tea ☕: this is a long parameter, and when you set it to 1, you're telling the library not to allow URLs that include a username. like, ever. no sneaky user@host business in your URL. not today, not on my watch 💅

and if you're wondering "hmm, this feels familiar" — you're so right, bestie, because it's the equivalent to the CURLU_DISALLOW_USER flag for the curl_url_set(3) function. same energy, different doorway. iykyk ✨

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🎀 DEFAULT 🎀

0 (disabled)

so by default the username-in-URL thing is allowed. you have to opt in to the strictness. main character behavior is opt-in only, periodt 💖

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🌈 PROTOCOLS 🌈

this functionality affects all supported protocols. every single one. no cap, no exceptions, it's giving "universal" 🔥

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🧚 EXAMPLE 🧚

okay here's the little demo, copy it exactly because i said so:

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {

    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    curl_easy_setopt(curl, CURLOPT_DISALLOW_USERNAME_IN_URL, 1L);

    curl_easy_perform(curl);
  }
}

see how it sets CURLOPT_URL to "https://example.com" and then flips CURLOPT_DISALLOW_USERNAME_IN_URL to 1L? that's the whole recipe 🫶 observe and learn, bestie.

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⭐ AVAILABILITY ⭐

Added in curl 7.61.0 — so she's been around a minute, an elder icon, but still slaying 💀✨

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💜 RETURN VALUE 💜

curl_easy_setopt(3) returns a CURLcode indicating success or error. cute and simple.

CURLE_OK (0) means everything was OK. non-zero means an error occurred — go check libcurl-errors(3) for the full roster, bestie 😭

and here's the one to remember, no cap: curl_easy_perform(3) returns CURLE_LOGIN_DENIED if this option is enabled and a URL containing a username is specified. so yes — it will absolutely catch you. it's not bluffing 🚨

fr fr, if you turn this on and then feed it a username URL, CURLE_LOGIN_DENIED is coming for you. dramatic but accurate 💀

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👑 SEE ALSO 👑

• CURLOPT_PROTOCOLS_STR(3)
• CURLOPT_URL(3)
• curl_url_set(3)
• libcurl-security(3)

all the linked besties, go read them, i'll wait 🌸

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and that's the page, diva 💅 this one came from libcurl, dated 2026-10-12, and yeah the header/footer both say CURLOPT_DI...AME_IN_URL(3) because truncation is a lifestyle apparently. go forth and disallow usernames responsibly, bestie — mwah 🎀🦋💖