HP OpenVMS Systems Documentation

The following sections describe changes specific to OpenVMS programming utilities and their routines to support Extended File Specifications.

B.4.1 File Definition Language (FDL) Routines

The File Definition Language (FDL) routines have been enhanced on OpenVMS Version 7.2 for Alpha to support Extended File Specifications. A new flag, FDL$V_LONG_NAMES, has been added to the flags argument of the following routines:

FDL$CREATE
FDL$GENERATE
FDL$PARSE
FDL$RELEASE

The following sections describe the FDL$V_LONG_NAMES flag as it relates to each FDL routine.

B.4.1.1 FDL$CREATE Routine (Alpha Only)

The following new flag has been added to the flags argument:

The following new flag has been added to the flags argument:

The following new flag has been added to the flags argument:

The following new flag has been added to the flags argument:

To enable the use of extended file names, several routines in the LIB$ Run-Time Library have been modified so that they can optionally accept or return a NAML block rather than a NAM block. The following routines have been modified:

• LIB$CREATE_DIR
• LIB$DELETE_FILE
• LIB$FILE_SCAN
• LIB$FIND_FILE
• LIB$RENAME_FILE
• LIB$FID_TO_NAME

The maximum size of argument device-directory-spec is now 255 characters on VAX, and 4095 characters on Alpha.

B.5.2 LIB$DELETE_FILE

The format of LIB$DELETE_FILE is now:

LIB$DELETE_FILE     filespec [,default-filespec] [,related-filespec]
                    [,user-success-procedure] [,user-error-procedure]
                    [,user-confirm-procedure] [,user-specified-argument]
                    [,resultant-name] [,file-scan-context] [,flags])

The flags argument is new, and has the following format:

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

User flags. The flags argument is the address of an unsigned longword containing the user flags.

The flag bits and their corresponding symbols are described in the following table:

On Alpha systems, if you specify the user-confirm-procedure in the call to LIB$DELETE_FILE, and the LIB$M_FIL_LONG_NAMES flag is set, the FAB referenced by the fab argument to the confirm-procedure routine references a NAML block rather than a NAM block. The NAML block supports the use of long file names with a maximum length of NAML$C_MAXRSS. See the OpenVMS Record Management Services Reference Manual for information on NAML blocks.

LIB$DELETE_FILE has an additional condition value returned. LIB$INVARG indicates that an unspecified bit was set in the flags argument.

B.5.3 LIB$FILE_SCAN

The fab argument to LIB$FILE_SCAN can now reference either a NAM or NAML block.

B.5.4 LIB$FIND_FILE

On Alpha systems, support for file specifications longer than 255 bytes is provided only when the LIB$M_FIL_LONG_NAMES flag is set in the flags argument. When this flag is set, a NAML block (rather than a NAM block) is part of the context, and file specifications can have a maximum length of NAML$C_MAXRSS. See the OpenVMS Record Management Services Reference Manual for information on NAML blocks.

B.5.5 LIB$RENAME_FILE

The flags argument to LIB$RENAME_FILE has the following new bit:

On Alpha systems, if you specify the user-confirm-procedure in the call to LIB$RENAME_FILE, and the LIB$M_FIL_LONG_NAMES flag is set, the FAB referenced by the old-fab argument to the confirm-procedure routine references a NAML block rather than a NAM block. The NAML block supports the use of long file names with a maximum length of NAML$C_MAXRSS. See the OpenVMS Record Management Services Reference Manual for information on NAML blocks.

B.5.6 LIB$FID_TO_NAME

If the file specification is longer than can be accommodated by the filespec buffer, a directory in the path may be replaced by a DID abbreviation (see Section 3.2.2.1). If the file specification after DID abbreviation is longer than can be accommodated by the buffer, the file specification is truncated and, as in prior versions, LIB$_STRTRU is returned as an alternate success status. In the case of a dynamic descriptor, the maximum allows a string as large as 4095 bytes to be returned.

The DEC Multinational Character Set (MCS) consists of a definition of the characters identified by hexadecimal values 00 through FF, inclusive, that was created and used by Digital Equipment Corporation. The DEC MCS is divided into two parts, the ASCII 7-bit character set (identified by hexadecimal values 00 through 7F, inclusive), and the set of 8-bit characters identified by hexadecimal values 80 through FF, inclusive. The DEC MCS is familiar to most users of software created and sold by DIGITAL.

The Unicode Standard Character Set (UCS-2) is a definition, by The Unicode Consortium, of the set of 16-bit characters that can be identified by hexadecimal values 0000 through FFFF, inclusive.

The ISO Latin-1 character set is the UCS-2 definition of the 8-bit characters identified by hexadecimal values 00 through FF, inclusive. The ISO Latin-1 character set definition differs slightly from the DEC MCS definition of the hexadecimal values 80 through FF.

Table C-1 contains the DEC Multinational Character Set (MCS). Table C-1 indicates the characters that differ between the two character sets, and Figure C-1 shows the differing characters.

See The Unicode Standard, published by The Unicode Consortium, for details about the Unicode (UCS-2) character set.

Figure C-1 Differences Between DEC Multinational Character Set and ISO Latin-1 Character Set