---

c: Copyright (C) Daniel Stenberg, <daniel.se>, et al. SPDX-License-Identifier: curl Title: CURLOPT_USERAGENT Section: 3 Source: libcurl See-also:

• CURLOPT_CUSTOMREQUEST (3)
• CURLOPT_HTTPHEADER (3)
• CURLOPT_REFERER (3)
• CURLOPT_REQUEST_TARGET (3)

---

NAME

CURLOPT_USERAGENT - HTTP user-agent header

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USERAGENT, char *ua);

DESCRIPTION

Pass a pointer to a null-terminated string as parameter. It is used to set the User-Agent: header field in the HTTP request sent to the remote server. You can also set any custom header with CURLOPT_HTTPHEADER(3).

The application does not have to keep the string around after setting this option.

DEFAULT

NULL, no User-Agent: header is used by default.

PROTOCOLS

HTTP, HTTPS

EXAMPLE

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

    curl_easy_setopt(curl, CURLOPT_USERAGENT, "Dark Secret Ninja/1.0");

    curl_easy_perform(curl);
  }
}

AVAILABILITY

As long as HTTP is supported

RETURN VALUE

Returns CURLE_OK if HTTP is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.