Following this introduction are sections on Old Format, New Format, and EZ-SPOOL Processing.

EZSPL.SBR is a very useful utility, which is fully compatible with and may be used in place of the AMOS SPOOL subroutine. In A-Shell, in fact, SPOOL is implemented as an alias to EZSPL. EZSPL provides three main functions:

• It incorporates a screen preview facility, enabling the user to browse through the document either before or instead of sending it to a printer. This feature has been fully implemented under A-Shell. In fact, the A-Shell version of the viewer (known as EZ-TYPE or, under it’s latest incarnation, EZ-VUE) supports many enhancements over the AMOS version.

• It optionally provides a front-end printer selection, enabling the user to select the printer and various print options (such as banner, header, etc.). Many of the switches are specific to the AMOS environment, and so there is a fair amount of divergence here between the AMOS and A-Shell versions, but the concepts are similar and the differences can be handled in the configuration files, external to the application source code.

• It optionally provides transparent character translation through what it terms port filters. These enable programs written to generate escape sequences for specific printers to have their codes transparently modified to the sequences required for other printers as the documents are output.

Port filters are not implemented under A-Shell, but the equivalent functionality is available using either the COMMAND=SBX:<routine name> option in the printer initialization file, or traditional UNIX filters in the UNIX environment.

In addition to the above features, EZSPL, like SPOOL, performs the mundane task of sending the specified file to the specified print queue. Two calling formats are available, each described below, followed by the a brief discussion of the EZ-SPOOL configuration file processing.

SPOOL.SBR is handled by using the ALIAS facility in the A-Shell configuration file to redirect it to EZSPL.SBR, which supports a superset of the normal SPOOL.SBR capabilities.