More details on Lahey file formats and compilers

This help topic assumes that you have read Lahey and Fujitsu file formats.

Fortran-based EXES supplied with or created with GEMPACK will produce either Lahey or Fujitsu files, according to which compiler was used to create those EXEs.

Up to and including GEMPACK 6, the LF95 compiler was not supported. With GEMPACK 7(or later), the LF95 compiler IS supported. GEMPACK 11 also supports Intel and GFortran compilers.

Fortran-based EXES supplied with or created with GEMPACK 6.0 or below will not read the Fujitsu type of file and will only create the Lahey type of file.

Fortran-based EXES supplied with or created with GEMPACK 7.0 (or later) will read both types of files but will only write one type (according to which compiler was used to create those EXEs).

When a user installs the source code version of GEMPACK 7.0 (or later) he or she decides which compiler is to be used and whether supplied EXE files are of the LF90 or LF95 type. So on a given PC, the GEMPACK system is also either of Lahey or Fujitsu flavour. The executable image version of GEMPACK 7.0 (which needs no compiler) is supplied with LF90 EXEs and so is of Lahey flavour.

When a GEMPACK 7.0 (or later) EXE compiled with LF90 has to read a Fujitsu file, it first creates a temporary copy in Lahey format and then reads that. Similarly, when a GEMPACK 7.0 EXE compiled with LF95 has to read a Lahey file, it first creates a temporary copy in Fujitsu format and then reads that. The process is automatic and transparent to the user -- although there will be a performance cost.

To avoid this performance hit, or to enable GEMPACK 6 users to read data stored in Fujitsu files, you may need to translate data files between Lahey and Fujitsu formats. GEMPACK offers several conversion programs for this purpose. The official program is DOS-based, and called CONLF.EXE. Fuj2Lhy.EXE and Lhy2Fuj.EXE are similar to CONLF. ConvHAR is a Windows based program, written by Mark Horridge, which converts groups of files simultaneously. Also, ViewHAR can read or save in either format (so could be used to convert).

If you plan to create your own GEMPACK-based EXEs for use by other people, GEMPACK 7.0 (or later) is better than GEMPACK 6.0, because your EXEs will work with both file types.

Notes: LF95 for Linux, GFortran, and the Intel compilers use the same (Fujitsu) file format as LF95 for Win32. The Executable Image (GEMSIM) edition of GEMPACK contained LF90 EXE files up to GEMPACK 8, LF95 thereafter.

URL of this topic: www.copsmodels.com/webhelp/viewhar/hc_lhyfile.htm

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