The features described in this topic are obsolete
and should not be used in new IDL code.

CALL_EXTERNAL

The following keywords to the CALL_EXTERNAL function are obsolete.

Keywords

DEFAULT

This keyword is ignored on non-VMS platforms. Under VMS, it is a string containing the default device, directory, file name, and file type information for the file that contains the sharable image.

PORTABLE

Under VMS, causes CALL_EXTERNAL to use the IDL Portable calling convention for passing arguments to the called function instead of the default VMS LIB$CALLG convention. Under other operating systems, only the portable convention is available, so this keyword is quietly ignored.

If you are using the IDL Portable calling convention, the AUTO_GLUE or WRITE_WRAPPER keywords are available to simplify the task of matching the form in which IDL passes the arguments to the interface of your target function.

VAX_FLOAT (VMS Only)

If specified, all data passed to the called function is first converted to VAX F (single) or D (double) floating point formats. On return, any data passed by reference is converted back to the IEEE format used by IDL. This feature allows you to call code compiled to work with earlier versions of IDL, which used the old VAX formats.

The default setting for this keyword is FALSE, unless IDL was started with the VAX_FLOAT startup option, in which case the default is TRUE. See "Command Line Options" in Chapter 4 of Using IDL for details on this qualifier. You can change this setting at runtime using the VAX_FLOAT function.