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

HELP

The following keywords to the HELP procedure are obsolete.

ALL_KEYS

Set this keyword to show current function-key definitions as set by DEFINE_KEY. If no arguments are supplied, information on all function keys is displayed. If arguments are provided, they must be scalar strings containing the names of function keys, and information on the specified keys is given. Under UNIX, this keyword is different from KEYS because every key is displayed, no matter what its current programming. Setting ALL_KEYS is equivalent to setting both KEYS and FULL. Under Windows, every key is always displayed; setting KEYS produces the same result as setting ALL_KEYS.

CALLS

Set this keyword to a named variable in which to store the procedure call stack. Each string element contains the name of the program module, source file name, and line number. Array element zero contains the information about the caller of HELP, element one contains information about its caller, etc. This keyword is useful for programs that require traceback information.