The Set Logical Name routine requests the calling process's
    command language interpreter (CLI) to define or redefine a
    supervisor-mode process logical name. It provides the same
    function as the DCL command DEFINE.

    Format

      LIB$SET_LOGICAL  logical-name [,value-string] [,table]

                       [,attributes] [,item-list]

      Either the item-list or value-string argument must be
      specified. If both item-list and value-string are specified,
      the value-string argument is ignored.

1  –  Returns

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

2  –  Arguments

 logical-name

    OpenVMS usage:logical_name
    type:         character string
    access:       read only
    mechanism:    by descriptor

    Logical name to be defined or redefined. The logical-name
    argument contains the address of a descriptor pointing to this
    logical name string. The maximum length of a logical name is 255
    characters. Note that logical names are case sensitive.

 value-string

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    Value to be given to the logical name. The value-string argument
    contains the address of a descriptor pointing to this value
    string. The maximum length of a logical name value is 255
    characters.

    If omitted, an item list must be present to specify the values of
    the logical name.

 table

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    Name of the table in which to create the logical name. The table
    argument contains the address of a descriptor pointing to the
    logical name table. If no table is specified, LNM$PROCESS is used
    as the default.

 attributes

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Logical name or translation attributes. The attributes argument
    is the address of a longword bit mask that contains the logical
    name or translation attributes.

    LNM$M_CONFINE and LNM$M_NO_ALIAS are currently available logical
    name attributes. See the description of the $CRELNM system
    service in the VSI OpenVMS System Services Reference Manual: A-
    GETUAI for definitions of LNM$M_CONFINE and LNM$M_NO_ALIAS. If
    omitted, no special logical name attribute is established.

    If no item-list is specified, the translation attributes
    LNM$M_CONCEALED and LNM$M_TERMINAL may be specified. See
    the description of the ASSIGN command in the VSI OpenVMS DCL
    Dictionary for definitions of these attributes. If an item-list
    is specified, it will contain the translation attributes for each
    equivalence string in the attribute.

 item-list

    OpenVMS usage:item_list_3
    type:         unspecified
    access:       read only
    mechanism:    by reference, array reference

    Item list describing the equivalence names for this logical
    name. The item-list argument contains the address of an array
    that contains this item list. If item-list is not specified,
    the logical name will have only one value, as specified in the
    value-string argument. Item codes for use with this item list are
    included in libraries supplied by VSI in module $LNMDEF.

    Either value-string or item-list must be specified. If neither
    is specified, the LIB$_INVARG error is produced. If both value-
    string and item-list are specified, the value-string argument is
    ignored.

    If item-list is specified, only logical name attributes are
    permitted. Translation attributes appear in the item list.

    The item-list argument is needed only when you want to create
    multiple equivalence strings for a single logical name.