68 lines
1.4 KiB
Markdown
68 lines
1.4 KiB
Markdown
---
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c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
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SPDX-License-Identifier: curl
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Title: CURLOPT_LOCALPORTRANGE
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Section: 3
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Source: libcurl
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See-also:
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- CURLOPT_INTERFACE (3)
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- CURLOPT_LOCALPORT (3)
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---
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# NAME
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CURLOPT_LOCALPORTRANGE - number of additional local ports to try
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# SYNOPSIS
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~~~c
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#include <curl/curl.h>
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CURLcode curl_easy_setopt(CURL *handle, CURLOPT_LOCALPORTRANGE,
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long range);
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~~~
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# DESCRIPTION
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Pass a long. The *range* argument is the number of attempts libcurl makes
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to find a working local port number. It starts with the given
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CURLOPT_LOCALPORT(3) and adds one to the number for each retry. Setting
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this option to 1 or below makes libcurl only do one try for the exact port
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number. Port numbers by nature are scarce resources that are busy at times so
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setting this value to something too low might cause unnecessary connection
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setup failures.
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# DEFAULT
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1
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# PROTOCOLS
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All
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# EXAMPLE
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~~~c
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int main(void)
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{
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CURL *curl = curl_easy_init();
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if(curl) {
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CURLcode res;
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curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
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curl_easy_setopt(curl, CURLOPT_LOCALPORT, 49152L);
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/* and try 20 more ports following that */
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curl_easy_setopt(curl, CURLOPT_LOCALPORTRANGE, 20L);
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res = curl_easy_perform(curl);
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curl_easy_cleanup(curl);
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}
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}
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~~~
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# AVAILABILITY
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Added in 7.15.2
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# RETURN VALUE
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Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
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