The LBR$REPLACE_KEY routine modifies or inserts a key into the
    library.

    Format

      LBR$REPLACE_KEY  library_index ,key_name ,oldrfa ,newrfa [,

                       flags]

1 - Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

    Longword condition value. Most utility routines return a
    condition value. Condition values that this routine can return
    are listed under Condition Values Returned.

2 - Arguments

 library_index

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Library control index returned by the LBR$INI_CONTROL routine.
    The library_index argument is the address of the longword that
    contains the index.

 key_name

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    For libraries with ASCII keys, the key_name argument is the
    address of a string descriptor for the key.

    For libraries with binary keys, the key_name argument is the
    address of an unsigned longword value for the key.

 oldrfa

    OpenVMS usage:vector_longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Old record file address (RFA). The oldrfa argument is the address
    of a 2-longword array containing the original RFA (returned by
    LBR$LOOKUP_KEY) of the module header associated with the key you
    are replacing.

 newrfa

    OpenVMS usage:vector_longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    New RFA. The newrfa argument is the address of a 2-longword array
    containing the RFA (returned by LBR$PUT_RECORD) of the module
    header associated with the new key.

 flags

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    If present, the flags argument specifies the type of key being
    replaced. The flag bits are as follows:

    Flag Bits              Description

    LBR$SYM_WEAK = 0x1     UNIX-style weak symbol attribute
    LBR$SYM_GROUP = 0x2    Group symbol attribute

    If this argument is not present, NonGroup-Global is the assumed
    type. In this case, all type lists are searched and the entries
    removed. The new symbol is placed in the new NonGroup-Global
    definition with newrfa as the defining module.

    If this parameter is present, it represents the flags set for
    the type of symbol being replaced. The replacement is done
    in place without losing its position in the type list. If the
    symbol does not exist when the call to this routine is made,
    the new definition is placed at the end of the type list for the
    specified type.

    Because there are now different symbol definition types, HP
    advises using the LBR$DELETE_KEY routine followed by the
    LBR$INSERT_KEY routine when the old key and new key differ in
    definition type.

3 - Description

    If LBR$REPLACE_KEY does not find the key in the current index,
    it calls the LBR$INSERT_KEY routine to insert the key. If
    LBR$REPLACE_KEY does find the key, it modifies the key entry
    in the index so that it points to the new module header.

4 - Condition Values Returned

    LBR$_ILLCTL        Specified library control index not valid.
    LBR$_INVRFA        Specified RFA not valid.
    LBR$_LIBNOTOPN     Specified library not open.