curl/docs/libcurl/opts/CURLOPT_LOCALPORTRANGE.3

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.TH CURLOPT_LOCALPORTRANGE 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_LOCALPORTRANGE \- number of additional local ports to try
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_LOCALPORTRANGE,
                          long range);
.fi
.SH DESCRIPTION
Pass a long. The \fIrange\fP argument is the number of attempts libcurl will
make to find a working local port number. It starts with the given
\fICURLOPT_LOCALPORT(3)\fP 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.
.SH DEFAULT
1
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
  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);
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}
.fi
.SH AVAILABILITY
Added in 7.15.2
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLOPT_LOCALPORT "(3), " CURLOPT_INTERFACE "(3), "