The Fit Long File Specification into Fixed Field routine takes a
    file specification, such as an OpenVMS RMS resultant name string,
    and shortens it (if necessary) so that it fits into a field of
    fixed width.

    Format

      LIB$TRIM_FILESPEC  old-filespec ,new-filespec

                         [,word-integer-width] [,resultant-length]

1  –  Returns

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

2  –  Arguments

 old-filespec

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

    File specification to be trimmed. The old-filespec argument
    contains the address of a descriptor pointing to this file
    specification string.

    The file specification should be an RMS resultant name string.

 new-filespec

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

    Trimmed file specification. The new-filespec argument contains
    the address of a descriptor pointing to this trimmed file
    specification string. LIB$TRIM_FILESPEC writes the trimmed file
    specification into new-filespec.

 word-integer-width

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       read only
    mechanism:    by reference

    Maximum field width desired. The word-integer-width argument is
    the address of an unsigned word that contains this maximum field
    width.

    If omitted, the current length of new-filespec is used. If new-
    filespec is not a fixed-length string, you should specify word-
    integer-width to ensure that the desired width is used.

 resultant-length

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference

    Length of the trimmed file specification, not including any blank
    padding or truncated characters. The resultant-length argument is
    the address of an unsigned word that contains this length. This
    is an optional argument.