curl_multi_fdset(3)

curl_multi_fdset(3)      libcurl Manual       curl_multi_fdset(3)

NAME

     curl_multi_fdset - extracts file descriptor information from
     a multi handle

SYNOPSIS

     #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);

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
     curl_multi_fdset(3) only adds its own descriptors it doesn't
     zero     or     otherwise     remove    any    other.    The
     curl_multi_perform(3) 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, max_fd will  con-
     tain  -1  when this function returns. Otherwise it will con-
     tain 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  curl_multi_perform  regularly  -
     even if no activity has been seen on the fd_sets - as other-
     wise libcurl-internal retries and timeouts may not  work  as
     you'd think and want.

RETURN VALUE

     CURLMcode type, general libcurl multi interface error  code.
     See libcurl-errors(3)

SEE ALSO

     curl_multi_cleanup(3),curl_multi_init(3)

libcurl 7.9.5       Last change: 25 Apr 2005                    1