CURLOPT_LOCALPORTRANGE(3)

CURLOPT_LOCALPORTRANGE(3curl_easy_setopt optionCURLOPT_LOCALPORTRANGE(3)

NAME

     CURLOPT_LOCALPORTRANGE - number of additional local ports to
     try

SYNOPSIS

     #include <curl/curl.h>

     CURLcode           curl_easy_setopt(CURL            *handle,
     CURLOPT_LOCALPORTRANGE,
                               long range);

DESCRIPTION

     Pass a long. The range argument is the  number  of  attempts
     libcurl  will  make  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
     will make libcurl do only one try for the exact port number.
     Port  numbers  by  nature  are scarce resources that will be
     busy at times so setting this value  to  something  too  low
     might cause unnecessary connection setup failures.

DEFAULT

     1

PROTOCOLS

     All

EXAMPLE

     CURL *curl = curl_easy_init();
     if(curl) {
       curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/foo.bin");
       curl_easy_setopt(curl, CURLOPT_LOCALPORT, 8080L);
       /* and try 20 more ports following that */
       curl_easy_setopt(curl, CURLOPT_LOCALPORTRANGE, 20L);
       ret = curl_easy_perform(curl);
       curl_easy_cleanup(curl);
     }

AVAILABILITY

     Added in 7.15.2

RETURN VALUE

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

SEE ALSO

     CURLOPT_LOCALPORT(3), CURLOPT_INTERFACE(3),

libcurl 7.58.0      Last change: May 31, 2017                   1