CURLOPT_LOCALPORTRANGE(3)

CURLOPT_LOCALPORTRANGE3

Number of additional local ports to try

Usage

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_LOCALPORTRANGE,
                          long range);

Overview

Pass a long. The range argument is the number of attempts libcurl makes to find a working local port number. It starts with the given CURLOPT_LOCALPORT(3) and adds one to the number for each retry. Setting this option to 1 or below makes libcurl only do one try for the exact port number. Port numbers by nature are scarce resources that are busy at times so setting this value to something too low might cause unnecessary connection setup failures.

Default

1

Protocols

All

Examples

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
    curl_easy_setopt(curl, CURLOPT_LOCALPORT, 49152L);
    /* and try 20 more ports following that */
    curl_easy_setopt(curl, CURLOPT_LOCALPORTRANGE, 20L);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Return value

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

Releases

79 releases since OS X 10.10; the text changed 13 times.

  1. 10.10–10.11.6
  2. 10.12–10.12.5
  3. 10.12.6–10.14.6
  4. 10.15–11.5
  5. 12.0.1–12.2
  6. 12.3–12.5
  7. 13.0
  8. 13.1
  9. 13.2
  10. 13.3
  11. 13.4
  12. 13.5–14.1
  13. 14.2–14.4
  14. 14.5–26.5

Availability

Added in 7.15.2

From curl 166.0.0.0.1 in macOS 26.5. Parsed by carta from the page's man source.