curl_multi_fdset(3)       libcurl Manual      curl_multi_fdset(3)



NAME
       curl_multi_fdset  -  extracts  file descriptor information
       from a multi handle

SYNOPSIS
       #include 

       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
       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 curl_multi_perform 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
       curl_multi_timeout  to  figure  out  how  long to wait for
       action.

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

SEE ALSO
       curl_multi_cleanup(3),curl_multi_init(3), curl_multi_time-
       out(3)



libcurl 7.16.0              2 Jan 2006        curl_multi_fdset(3)