HELPLIB.HLB  —  DCX Routines, DCX$EXPAND_DATA
    The DCX$EXPAND_DATA routine expands (or restores) a compressed
    data record to its original state.

    Format

      DCX$EXPAND_DATA  context ,in_rec ,out_rec [,out_length]

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

 context

    OpenVMS usage:context
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Value identifying the data stream that DCX$EXPAND_DATA expands.
    The context argument is the address of a longword containing this
    value. DCX$EXPAND_INIT initializes this value; you should not
    modify it. You can define multiple context arguments to identify
    multiple data streams that are processed simultaneously.

 in_rec

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    Data record to be expanded. The in_rec argument is the address of
    the descriptor of the data record string.

 out_rec

    OpenVMS usage:char_string
    type:         character string
    access:       write only
    mechanism:    by descriptor
    Data record that has been expanded. The out_rec argument is the
    address of the descriptor of the expanded record returned by
    DCX$EXPAND_DATA.

 out_length

    OpenVMS usage:word_signed
    type:         word integer (signed)
    access:       write only
    mechanism:    by reference
    Length (in bytes) of the expanded data record. The out_length
    argument is the address of a word into which DCX$EXPAND_DATA
    returns the length of the expanded data record.

3  –  Description

    The DCX$EXPAND_DATA routine expands (or restores) a compressed
    data record to its original state. Call this routine for each
    data record to be expanded.

4  –  Condition Values Returned

    DCX$_INVCTX        Error. The context variable is invalid, or the
                       context area is invalid or corrupted. This may
                       be caused by a failure to call the appropriate
                       routine to initialize the context variable or
                       by an application program error.
    DCX$_INVDATA       Error. A compressed data record is invalid
                       (probably truncated) and therefore cannot be
                       expanded.
    DCX$_INVMAP        Error; invalid map. The map argument was not
                       specified correctly, or the context area is
                       invalid.
    DCX$_NORMAL        Normal successful completion.
    DCX$_TRUNC         Warning. The expanded data record has been
                       truncated because the out_rec descriptor did
                       not specify enough memory to accommodate the
                       record.

    This routine also returns any condition values returned by
    LIB$ANALYZE_SDESC_R2 and LIB$SCOPY_R_DX.
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