fm_write(_c)

	status.i4.v = fm_write(vun.i2.r, io_buffer.g.v, num_bytes.i4.r
			       [,record_number.i4.r] [,ext_status.i4.r]
			       [,no_modify.i4.r] [,asynchronous.i4.r])

	status.i4.v = fm_write_c(vun.i2.v, io_buffer.g.v, num_bytes.i4.v
				 [,record_number.i4.v] [,ext_status.i4.r]
				 [,no_modify.i4.v] [,asynchronous.i4.v])

	This routine writes a record to a Filesharing file opened on the
	virtual unit number.  The file may have either sequential or
	relative organization and fixed or variable length records.  The
	record is gotten into the user's buffer according to the number
	number of bytes specified.  If the file was opened with direct
	access, then the logical record number defines the record to be
	written.  If the file was opened with sequential access, then the
	next record in sequence is written.  If "asynchronous" is specified
	and has a value of TRUE, the read will be asynchronous with control
	being returned to the caller without waiting for the read to complete.

	vun		virtual unit number on which the file was opened
	io_buffer	user's record buffer containing the record to
			be written (Note: This must be the address of a
			byte array.)
	num_bytes	size of the record to be written in bytes
	[record_number]	logical record number for files opened for direct
			access (default is 0)
	[ext_status]	returned extended status from VMS/RMS (default is NULL)
	[no_modify]	record modification flag
			(new records are always written)
			(TRUE -> don't modify existing records,
			 FALSE -> modify existing records (default))
	[asynchronous]	asynchronous flag
			(TRUE -> write will be done asynchronously,
			 FALSE -> synchronous write (default))

	This function returns status values as follows:

	OK			success
	FSHARE_xxx		error writing file
	CBS_NOTOPN		VUN is not in use
	CBS_INVARG		number of bytes <= 0
	CBS_READONLY		file is opened for read access
	CBS_NOTENB		writing is disabled
	CBS_RANGE		attempted write beyond record limit
	event number		if successful asynchronous request

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	fm_io(_c), fm_open_write(_c), fm_read(_c), fm_write_enable,
	fm_write_disable

	C/C++ usage:

	char	io_buffer[NUM_BYTES];
	short	vun;
	int	status;
	int	num_bytes = NUM_BYTES;
	int	record_number = RECORD_NUMBER;
	int	ext_status;
	int	no_modify = FALSE;
	int	asynchronous = FALSE;

	status = fm_write_c(vun,(void *) io_buffer,num_bytes,record_number,
			    &ext_status,no_modify,asynchronous);