curl/docs/libcurl/opts/CURLOPT_LOCALPORT.md
Daniel Stenberg 8c1d9378ac
curldown: make 'added-in:' a mandatory header field
- generate AVAILABILITY manpage sections automatically - for consistent
  wording

- allows us to double-check against other documumentation (symbols-in-versions
  etc)

- enables proper automation/scripting based on this data

- lots of them were wrong or missing in the manpages

- several of them repeated (sometimes mismatching) backend support info

Add test 1488 to verify "added-in" version numbers against
symbols-in-versions.

Closes #14217
2024-07-18 18:04:09 +02:00

1.2 KiB

c SPDX-License-Identifier Title Section Source See-also Protocol Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLOPT_LOCALPORT 3 libcurl
CURLINFO_LOCAL_PORT (3)
CURLOPT_INTERFACE (3)
CURLOPT_LOCALPORTRANGE (3)
All
7.15.2

NAME

CURLOPT_LOCALPORT - local port number to use for socket

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_LOCALPORT, long port);

DESCRIPTION

Pass a long. This sets the local port number of the socket used for the connection. This can be used in combination with CURLOPT_INTERFACE(3) and you are recommended to use CURLOPT_LOCALPORTRANGE(3) as well when this option is set. Valid port numbers are 1 - 65535.

DEFAULT

0, disabled - use whatever the system thinks is fine

EXAMPLE

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