The LBR$GET_HEADER routine returns information from the library's
    header to the caller.

    Format

      LBR$GET_HEADER  library_index ,retary

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 in R0. 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.

 retary

    OpenVMS usage:vector_longword_unsigned
    type:         longword (unsigned)
    access:       write only
    mechanism:    by reference
    Array of 128 longwords that receives the library header. The
    retary argument is the address of the array that contains the
    header information. The information returned in the array is
    listed in the following table. Each programming language provides
    an appropriate mechanism for accessing this information.

    Offset
    in
    Longwords Symbolic Name  Contents

     0        LHI$L_TYPE     Library type (see LBR$OPEN for possible
                             values)
     1        LHI$L_NINDEX   Number of indexes
     2        LHI$L_MAJORID  Library format major identification
     3        LHI$L_MINORID  Library format minor identification
     4        LHI$T_LBRVER   ASCIC version of Librarian
    12        LHI$L_CREDAT   Creation date/time
    14        LHI$L_UPDTIM   Date/time of last update
    16        LHI$L_UPDHIS   Virtual block number (VBN) of start of
                             update history
    17        LHI$L_FREEVBN  First logically deleted block
    18        LHI$L_FREEBLK  Number of deleted blocks
    19        LHI$B_NEXTRFA  Record file address (RFA) of end of
                             library
    21        LHI$L_NEXTVBN  Next VBN to allocate at end of file
    22        LHI$L_         Number of free preallocated index blocks
              FREIDXBLK
    23        LHI$L_FREEIDX  List head for preallocated index blocks
    24        LHI$L_HIPREAL  VBN of highest preallocated block
    25        LHI$L_IDXBLKS  Number of index blocks in use
    26        LHI$L_IDXCNT   Number of index entries (total)
    27        LHI$L_MODCNT   Number of entries in index 1 (module
                             names)
    28        LHI$L_MHDUSZ   Number of bytes of additional
                             information reserved in module header
    29        LHI$L_         Maximum number of library update history
              MAXLUHREC      records maintained
    30        LHI$L_         Number of library update history records
              NUMLUHREC      in history
    31        LHI$L_         Library status (false if there was an
              LIBSTATUS      error closing the library)
    32-128                   Reserved by VSI

3  –  Description

    On successful completion, LBR$GET_HEADER places the library
    header information into the array of 128 longwords.

    Note that the offset is the byte offset of the value into the
    header structure. You can convert the offset to a longword
    subscript by dividing the offset by 4 and adding 1 (assuming
    that subscripts in your programming language begin with 1).

4  –  Condition Values Returned

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