Selecting a Device Group (C Program)

You should recall that DFSETUP insists that a POD based on COD '1' is defined for any Device Group (See device definition). This is the initialisation POD and you must use it to select a Device Group, as follows:

int dvc_choose(int device_flags, int POD,char * filename,int print_width)

The dvc_choose() function initialises the Device Group. The parameters are:

1. device_flags Selects a list of devices that will receive subsequent printer output; any combination of the screen printer and file can be selected

2. POD Selects the POD (which should be the initialisation POD)

3. filename If FILE has been selected in 'device_flags' then this parameter will be the address of the filename. The file output will be formatted in the style selected by the POD

4. print_width This parameter specifies a fixed print width and is only used if the flag FIXED_WIDTH is passed as a device flag

   You must call dvc_choose() or the similar function dvc_open() (which takes the same parameters but is non interactive) to select a Device Group (via the initialisation POD) before you can use a POD or input device belonging to that Device Group.