| .\" $Id$ |
| .\" |
| .TH curl_multi_fdset 3 "2 Jan 2006" "libcurl 7.16.0" "libcurl Manual" |
| .SH NAME |
| curl_multi_fdset - extracts file descriptor information from a multi handle |
| .SH SYNOPSIS |
| .nf |
| #include <curl/curl.h> |
| |
| CURLMcode curl_multi_fdset(CURLM *multi_handle, |
| fd_set *read_fd_set, |
| fd_set *write_fd_set, |
| fd_set *exc_fd_set, |
| int *max_fd); |
| .ad |
| .SH DESCRIPTION |
| This function extracts file descriptor information from a given multi_handle. |
| libcurl returns its fd_set sets. The application can use these to select() on, |
| but be sure to FD_ZERO them before calling this function as |
| \fIcurl_multi_fdset(3)\fP only adds its own descriptors it doesn't zero or |
| otherwise remove any other. The \fIcurl_multi_perform(3)\fP function should be |
| called as soon as one of them are ready to be read from or written to. |
| |
| If no file descriptors are set by libcurl, \fImax_fd\fP will contain -1 when |
| this function returns. Otherwise it will contain the higher descriptor number |
| libcurl set. |
| |
| You should also be aware that when doing select(), you should consider using a |
| rather small (single-digit number of seconds) timeout and call |
| \fIcurl_multi_perform\fP regularly - even if no activity has been seen on the |
| fd_sets - as otherwise libcurl-internal retries and timeouts may not work as |
| you'd think and want. |
| |
| Starting with libcurl 7.16.0, you should use \fBcurl_multi_timeout\fP to |
| figure out how long to wait for action. |
| .SH RETURN VALUE |
| CURLMcode type, general libcurl multi interface error code. See |
| \fIlibcurl-errors(3)\fP |
| .SH "SEE ALSO" |
| .BR curl_multi_cleanup "(3)," curl_multi_init "(3), " |
| .BR curl_multi_timeout "(3) " |