2024-03-15 20:55:33 -06:00
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.\" generated by cd2nroff 0.1 from curl_easy_send.md
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2024-07-29 18:00:04 -06:00
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.TH curl_easy_send 3 "2024-07-29" libcurl
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2024-03-15 20:55:33 -06:00
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.SH NAME
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curl_easy_send \- sends raw data over an "easy" connection
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.SH SYNOPSIS
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.nf
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#include <curl/curl.h>
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CURLcode curl_easy_send(CURL *curl, const void *buffer,
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size_t buflen, size_t *n);
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.fi
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.SH DESCRIPTION
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This function sends arbitrary data over the established connection. You may
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use it together with \fIcurl_easy_recv(3)\fP to implement custom protocols
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using libcurl. This functionality can be particularly useful if you use
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proxies and/or SSL encryption: libcurl takes care of proxy negotiation and
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connection setup.
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\fBbuffer\fP is a pointer to the data of length \fBbuflen\fP that you want
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sent. The variable \fBn\fP points to receives the number of sent bytes.
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To establish the connection, set \fICURLOPT_CONNECT_ONLY(3)\fP option before
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calling \fIcurl_easy_perform(3)\fP or \fIcurl_multi_perform(3)\fP. Note that
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\fIcurl_easy_send(3)\fP does not work on connections that were created without
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this option.
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The call returns \fBCURLE_AGAIN\fP if it is not possible to send data right now
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- the socket is used in non\-blocking mode internally. When \fBCURLE_AGAIN\fP
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is returned, use your operating system facilities like \fIselect(2)\fP to wait
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until the socket is writable. The socket may be obtained using
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\fIcurl_easy_getinfo(3)\fP with \fICURLINFO_ACTIVESOCKET(3)\fP.
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Furthermore if you wait on the socket and it tells you it is writable,
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\fIcurl_easy_send(3)\fP may return \fBCURLE_AGAIN\fP if the only data that was sent
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was for internal SSL processing, and no other data could be sent.
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2024-03-30 12:28:04 -06:00
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.SH PROTOCOLS
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This functionality affects all supported protocols
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.SH EXAMPLE
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.nf
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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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/* Do not do the transfer - only connect to host */
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curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
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res = curl_easy_perform(curl);
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if(res == CURLE_OK) {
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long sockfd;
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size_t sent;
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/* Extract the socket from the curl handle - we need it for waiting. */
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res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);
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/* send data */
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res = curl_easy_send(curl, "hello", 5, &sent);
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}
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}
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}
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.fi
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.SH AVAILABILITY
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Added in curl 7.18.2
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.SH RETURN VALUE
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On success, returns \fBCURLE_OK\fP and stores the number of bytes actually
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sent into \fB*n\fP. Note that this may be less than the amount you wanted to
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send.
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On failure, returns the appropriate error code.
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This function may return \fBCURLE_AGAIN\fP. In this case, use your operating
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system facilities to wait until the socket is writable, and retry.
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If there is no socket available to use from the previous transfer, this function
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returns \fBCURLE_UNSUPPORTED_PROTOCOL\fP.
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.SH SEE ALSO
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.BR curl_easy_getinfo (3),
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.BR curl_easy_perform (3),
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.BR curl_easy_recv (3),
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.BR curl_easy_setopt (3)
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