NAME
curlmultiperform - reads/writes available data from each easy handle
SYNOPSIS
#include
CURLMcode curlmultiperform(CURLM *multihandle, int *runninghan-
dles);DESCRIPTION
When the app thinks there's data available for the multihandle, it should call this function to read/write whatever there is to read or write right now. curlmultiperform() returns as soon as thereads/writes are done. This function does not require that there actu-
ally is any data available for reading or that data can be written, it can be called just in case. It will write the number of handles thatstill transfer data in the second argument's integer-pointer.
When you call curlmultiperform() and the amount of runninghandles ischanged from the previous call (or is less than the amount of easy han-
dles you've added to the multi handle), you know that there is one or more transfers less "running". You can then callcurlmultiinforead(3) to get information about each individual com-
pleted transfer, and that returned info includes CURLcode and more. RREETTUURRNN VVAALLUUEE CURLMcode type, general libcurl multi interface error code. If you receive CURLMCALLMULTIPERFORM, this basically means that you should call curlmultiperform again, before you select() on more actions. You don't have to do it immediately, but the return code means that libcurl may have more data available to return or that there may be more data to send off before it is "satisfied".NOTE that this only returns errors etc regarding the whole multi stack.
There might still have occurred problems on individual transfers even when this function returns OK. TTYYPPIICCAALL UUSSAAGGEE Most application will use curlmultifdset(3) to get the multihandle's file descriptors, then it'll wait for action on them using select() and as soon as one or more of them are ready, curlmultiperform(3) gets called.SEE ALSO
ccuurrllmmuullttiicclleeaannuupp(3), ccuurrllmmuullttiiiinniitt(3), ccuurrllmmuullttiiffddsseett(3), ccuurrllmmuullttiiiinnffoorreeaadd(3) libcurl 7.9.5 1 March 2002 curlmultiperform(3)