Flexible Input/Output File Naming

Up to now, EMME/2 used fixed file names for all input and output operations, such as printing reports, generating plot files, punching out data sets and reading in data using batch entry. On PC and UNIX systems, the file names "REPORTS", "PLOTS", "BATCHOUT" and "Dxyy.IN" are used, whereas on VAX/VMS systems the standard names are "REPORTS.LIS", "PLOTS.DAT", "Bxyy.IN" and "Dxyy.IN".

In Release 5.0, this rigid file naming scheme has been replaced by flexible file naming. This new feature provides the four new menu commands reports=, plots=, batchout= and batchin= to redefine the files names to be used for reports, plots, batch output and batch input. A fifth new menu command files is used to display the currently active file naming conventions.

Flexible file naming offers the following advantages:

• Upward compatibility; by default, the same standard file names are used as before.
• Any file name permitted by the operating system can be used. This includes files on different disk drives, device drivers (e.g. "reports=lpt1" on PCs) and file access through a local area network. On systems that provide a null device (such as "NUL" under DOS, and "/dev/null" under UNIX), it can be used to suppress the output of unwanted reports.
• By using "?" in the specified file names, the user will be prompted to enter a name interactively just before the file is to be opened. Since the "?" may be preceded and/&or followed optionally by file prefix and suffix information, the user only needs to specify the relevant part of the file name.
• File names may contain parameters, which are substituted at the time that a file is opened. The following parameters are available:

  %d% current date in the format "yymmdd"

  %m% current module number

  %s% current scenario number

  %u% user initials

  With this substitution mechanism, many useful automatic file naming schemes can be defined, e.g. "reports=rep%s%.%u%" would create separate report files for each scenario and each user.

With the new file naming scheme, the input/output files are only opened just before they are needed. As a consequence, none of the four files is open at the level of the main menu. This implies that command escapes which manipulate these files (such as "erase reports") can be used safely at the level of the main menu. Also, this type of commands no longer causes file access conflicts, even when the corresponding files are opened with exclusive access privileges. On DOS systems in particular, SHARE.EXE no longer causes conflicts with macros that use command escapes at the menu level. Thus, if you have previously removed the SHARE utility to avoid these conflicts, it is recommended that you reinstall it now with Release 5.0.

For more details on the new flexible file naming refer to sections III-2.6 and III-4.1.1 of the EMME/2 User's Manual.