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--- |
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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: curl_easy_perform |
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Section: 3 |
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Source: libcurl |
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See-also: |
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- curl_easy_init (3) |
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- curl_easy_setopt (3) |
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- curl_multi_add_handle (3) |
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- curl_multi_perform (3) |
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- libcurl-errors (3) |
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Protocol: |
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- All |
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Added-in: 7.1 |
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--- |
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# NAME |
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curl_easy_perform - perform a blocking network transfer |
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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_perform(CURL *easy_handle); |
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~~~ |
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# DESCRIPTION |
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curl_easy_perform(3) performs a network transfer in a blocking manner and |
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returns when done, or earlier if it fails. For non-blocking behavior, see |
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curl_multi_perform(3). |
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Invoke this function after curl_easy_init(3) and all the curl_easy_setopt(3) |
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calls are made, and it performs the transfer as described in the options. It |
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must be called with the same **easy_handle** as input as the curl_easy_init(3) |
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call returned. |
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You can do any amount of calls to curl_easy_perform(3) while using the same |
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**easy_handle**. If you intend to transfer more than one file, you are even |
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encouraged to do so. libcurl attempts to reuse existing connections for the |
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following transfers, thus making the operations faster, less CPU intense and |
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using less network resources. You probably want to use curl_easy_setopt(3) |
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between the invokes to set options for the following curl_easy_perform(3) |
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call. |
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You must never call this function simultaneously from two places using the |
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same **easy_handle**. Let the function return first before invoking it another |
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time. If you want parallel transfers, you must use several curl easy_handles. |
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A network transfer moves data to a peer or from a peer. An application tells |
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libcurl how to receive data by setting the CURLOPT_WRITEFUNCTION(3) and |
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CURLOPT_WRITEDATA(3) options. To tell libcurl what data to send, there are a |
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few more alternatives but two common ones are CURLOPT_READFUNCTION(3) and |
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CURLOPT_POSTFIELDS(3). |
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While the **easy_handle** is added to a multi handle, it cannot be used by |
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curl_easy_perform(3). |
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# %PROTOCOLS% |
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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"); |
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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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# RETURN VALUE |
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CURLE_OK (0) means everything was OK, non-zero means an error occurred as |
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*\<curl/curl.h\>* defines - see libcurl-errors(3). If CURLOPT_ERRORBUFFER(3) |
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was set with curl_easy_setopt(3) there is an error message stored in the error |
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buffer when non-zero is returned. |
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