CURLOPT_PRIVATE(3)

💅 CURLOPT_PRIVATE(3) — the libcurl manual, bestie edition 🎀

ok so this is a page from the Library Functions Manual and it's literally all about CURLOPT_PRIVATE, which is your little "stash my own pointer here" button. no cap, it's the chillest option in the whole toolkit. ✨

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🌸 NAME 🌸

CURLOPT_PRIVATE — store a private pointer 🫶

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✨ SYNOPSIS ✨

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PRIVATE, void *pointer);

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💖 DESCRIPTION 💖

Okay so picture this: you pass a void * as the parameter, and that pointer points at whatever data you wanna associate with this curl handle. that's it. that's the whole vibe. 🦋

Later on you can pull that same pointer back out using curl_easy_getinfo(3) with the CURLINFO_PRIVATE(3) option — like checking your bag and getting your own stuff back, iconic behavior honestly.

and here's the important part, bestie: libcurl itself never does anything with this data. not a single thing. it just holds onto it for you like the world's most trustworthy friend. 💜

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🎀 DEFAULT 🎀

NULL

(as in, nothing stashed. empty bag. clean slate. 😌)

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🌈 PROTOCOLS 🌈

This functionality affects all supported protocols. every single one. she's universal. 👑

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⭐ EXAMPLE ⭐

struct private {
  void *custom;
};

int main(void)
{
  CURL *curl = curl_easy_init();
  struct private secrets;
  if(curl) {
    struct private *extracted;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

    /* store a pointer to our private struct */
    curl_easy_setopt(curl, CURLOPT_PRIVATE, &secrets);

    curl_easy_perform(curl);

    /* we can extract the private pointer again too */
    curl_easy_getinfo(curl, CURLINFO_PRIVATE, &extracted);
  }
}

see how it works?? you set it, curl carries it around for you, then you get it back. it's giving "emotional support pointer." 😭💖

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🦋 AVAILABILITY 🦋

Added in curl 7.10.3 — so yeah, she's been around a minute. vintage but make it fresh. ⭐

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🔥 RETURN VALUE 🔥

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

• CURLE_OK (0) means everything was OK — we love a zero. 🎉
• non-zero means an error occurred, so go peek at libcurl-errors(3) for the tea.

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👑 SEE ALSO 👑

• CURLINFO_PRIVATE(3)
• CURLOPT_STDERR(3)
• CURLOPT_VERBOSE(3)

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and that's the page, bestie!! go forth and stash your pointers responsibly 💅✨

mwah 💋 — this lil rewrite was brought to you by libcurl, dated 2026-10-12, on the CURLOPT_PRIVATE(3) page. slay, bye!! 🎀