NAME¶
FtpOptions - Set connection options.
SYNOPSIS¶
#include <ftplib.h>
int FtpOptions(int opt, long val, netbuf
*nControl);
PARAMETERS¶
- opt
- Specifies the option to change. Valid options are
FTPLIB_CONNMODE, FTPLIB_CALLBACK, FTPLIB_IDLETIME, FTPLIB_CALLBACKARG, and
FTPLIB_CALLBACKBYTES.
- val
- Specifies the new value for the option. The value may need
to by cast to a long.
- nControl
- A handle returned by FtpConnect()or FtpAccess().
DESCRIPTION¶
FtpOptions() changes the options for a connection handle. A data connection
inherits the options assigned to the control connection it is created from.
Callbacks are only called on file data connections.
The following options and values are recognized.OptionValueFTPLIB_CONNMODE
Specifies the connection mode. Either FTPLIB_PASSIVE or
FTPLIB_PORT.FTPLIB_CALLBACK Specifies the address of a user callback
routine.FTPLIB_IDLETIME Specifies the socket idle time in milliseconds that
triggers calling the user's callback routine.FTPLIB_CALLBACKARG Specifies an
argument to pass to the user's callback routine.FTPLIB_CALLBACKBYTES Specifies
the number of bytes to transfer between calls to the user's callback routine.
The connection mode tells ftplib if it should use PASV or PORT to establish data
connections. The default is specified as a build option.
The user's callback routine is specified as:.sp
typedef int
(*FtpCallback)(netbuf *nControl, int xfered,
void *arg); nControlis
the data connection in use. xferedspecifies how many bytes of data have been
transferred on the connection.argis the value specified with option
FTPLIB_CALLBACKARG.
The user can request to be called back on either of two events.
If the user wishes to be called when the data socket is idle for some period of
time, use FTPLIB_IDLETIME and pass the time in milliseconds.
If the user wishes to be called when a certain amount of data has been
transferred, use FTPLIB_CALLBACKBYTES and pass the minimum number of bytes to
transfer between callbacks. When using this option, ftplib keeps track of the
number of bytes transferred and calls the user once the specified number of
bytes or more has been transferred. It then resets the count to 0 and starts
again.
If the user wishes to continue the transfer, the callback routine should return
true (non-zero). It can abort the transfer by return zero.
RETURN VALUE¶
Returns 1 if a valid option was specified and the value is legal. Otherwise,
returns 0.