Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

Chapter 9 259
Intrinsics Reference (cont)
HPFOPEN
NOTE All item parameters of type character array (CA), except for the fill
character option (Item# = 45), must be delimited by a single
character which appears only as the first and last element of the
specified character array. For example:
%filename% (% is the delimiter, filename is the
designator)
fabcxyzf (f is the delimiter, abcxyz is the designator)
Item Number, Item Summary
The following discussion lists the optional itemnum/item pairs. A
short descriptive name is provided for each pair, along with a mnemonic
indicating the parameter type of each
item . All item parameters are
passed by reference.
Item# = 0 Indicates end of the option list. This is the only
itemnum that does not have a corresponding item . The
absence of an
itemnum after the last itemnum/item
pair is equivalent to specifying this option.
Item# = 2 formaldesignator option (CA)
Passes a string to be associated with the file as its
formal file designator. The string can contain
alphanumeric characters, slashes, or periods and
terminates with any nonalphanumeric character except
a slash (/), a colon (:), or a period (.). If the string is the
name of a system defined file, it will begin with a dollar
sign ($). If the string is the name a user predefined file,
it can begin with an asterisk (*). You can specify the
remote location of a device as filename:envid.
If you use one of the system defined files the file can be
used for either input, ($STDIN, STDINX) or output,
($STDLIST), but not for both.
Though not required, the use of a formal file designator
is recommended in programs written for asynchronous
devices because of the flexibility it provides. If no
formaldesignator is specified, a temporary nameless
file is assigned that you can read from or write to, but
not save.
Note that all character arrays must start on a halfword
boundary.
Item# = 3 domain option (I32)