.\" ************************************************************************** .\" * _ _ ____ _ .\" * Project ___| | | | _ \| | .\" * / __| | | | |_) | | .\" * | (__| |_| | _ <| |___ .\" * \___|\___/|_| \_\_____| .\" * .\" * Copyright (C) Daniel Stenberg, , et al. .\" * .\" * This software is licensed as described in the file COPYING, which .\" * you should have received as part of this distribution. The terms .\" * are also available at https://curl.se/docs/copyright.html. .\" * .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell .\" * copies of the Software, and permit persons to whom the Software is .\" * furnished to do so, under the terms of the COPYING file. .\" * .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY .\" * KIND, either express or implied. .\" * .\" * SPDX-License-Identifier: curl .\" * .\" ************************************************************************** .TH curl_multi_timeout 3 "2 Jan 2006" "libcurl" "libcurl" .SH NAME curl_multi_timeout \- how long to wait for action before proceeding .SH SYNOPSIS .nf #include CURLMcode curl_multi_timeout(CURLM *multi_handle, long *timeout); .fi .SH DESCRIPTION An application using the libcurl multi interface should call \fIcurl_multi_timeout(3)\fP to figure out how long it should wait for socket actions \- at most \- before proceeding. Proceeding means either doing the socket-style timeout action: call the \fIcurl_multi_socket_action(3)\fP function with the \fBsockfd\fP argument set to CURL_SOCKET_TIMEOUT, or call \fIcurl_multi_perform(3)\fP if you are using the simpler and older multi interface approach. The timeout value returned in the long \fBtimeout\fP points to, is in number of milliseconds at this moment. If 0, it means you should proceed immediately without waiting for anything. If it returns -1, there is no timeout at all set. An application that uses the multi_socket API SHOULD NOT use this function, but SHOULD instead use the \fICURLMOPT_TIMERFUNCTION(3)\fP option for proper and desired behavior. Note: if libcurl returns a -1 timeout here, it just means that libcurl currently has no stored timeout value. You must not wait too long (more than a few seconds perhaps) before you call curl_multi_perform() again. .SH EXAMPLE .nf struct timeval timeout; long timeo; curl_multi_timeout(multi_handle, &timeo); if(timeo < 0) /* no set timeout, use a default */ timeo = 980; timeout.tv_sec = timeo / 1000; timeout.tv_usec = (timeo % 1000) * 1000; /* wait for activities no longer than the set timeout */ select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout); .fi .SH TYPICAL USAGE Call \fIcurl_multi_timeout(3)\fP, then wait for action on the sockets. Figure out which sockets to wait for by calling \fIcurl_multi_fdset(3)\fP. When there is activity or timeout, call \fIcurl_multi_perform(3)\fP and then loop - until all transfers are complete. .SH AVAILABILITY This function was added in libcurl 7.15.4. .SH RETURN VALUE The standard CURLMcode for multi interface error codes. .SH "SEE ALSO" .BR curl_multi_fdset "(3), " curl_multi_info_read "(3), " .BR curl_multi_socket "(3), " curl_multi_setopt "(3) "