FirstBase: GENERATORS(5)

URL: http://www.firstbasesoftware.com/man/man5/generators.htm
Last modified: 12 September 1995
Copyright © by FirstBase Software.
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NAME

generators - FirstBase generators

SYNOPSIS

Description of behavior of FirstBase generators

DESCRIPTION

A FirstBase generator is a program that generates a data object. All FirstBase generators require a dictionary and behave in a similar manner. A generator dictionary is used to define an object to be generated.

All of these tools, and optionally, dbigen(1) itself, use a FirstBase index to generate the output from the database in a particular order. If this index is detected to be out of date or non-existent, it is regenerated automatically. An index is out of date if either the database or the index dictionary have changed.

This automatic regeneration can be turned off controlled via environment variables. See setup(5) for more.

The generatable objects are:

indexes: uses dbdind(1) and dbigen(1).
reports: uses dbdprt(1) and dbpgen(1).
labels: uses dbdlbl(1) and dblgen(1).
databases: uses dbdcnv(1) and dbcgen(1).
updates: uses dbdupd(1) and dbugen(1) (and dbrload(1)).

If invoked with the -b flag, generators will run in batch mode. If invoked with the -y flag, generators will run in yes mode. Both batch mode and yes mode will bypass any questions the user might need to answer, destroying any old files that are there, and start the generation task immediately, if possible.

The difference between batch mode and yes mode is that batch mode is completely silent about its operation -- no screen headers, no counters, no screen indication that the generator is running at all.

However, yes mode will display the motions of the generator, the screen headers, time and date, and record counting -- all without any user intervention.

Batch mode use can be executed from a shell file, making large data processing tasks that are repeated very easy to keep organized.

When a generator is used interactively, an image of the object about to be created will be shown on the screen. The user can abort at this point if necessary.

During actual generation, FirstBase generators display a count in the lower right quadrant of the number of processed objects. The behavior of this counter is controllable by an environment variable also. See setup(5).

SPECIAL CASE GENERATORS

There are a few special case generators that take different types of dictionaries (if they can be called dictionaries at all). These special generators are dbawk(1), dbmacro(1), dbmerge(1), dbsql(1), and dbvform(1).

Like the other generators, each of these can also works from an index. For these tools, the input dictionary or program is distinct in each case, and the output (generally) is a text object to be printed or used in UNIX (piped into another program, for example). Dbmacro and dbsql have some other features as well.

For information on these special generators, see the associated manual pages.

FILES

*.idx: FirstBase generated index.
*.prt: FirstBase print image report.
*.lbl: FirstBase print image of labels.
*.cdb: FirstBase database.
*.map: FirstBase database map file.

DIAGNOSTICS

All FirstBase generators will enforce record locking through the use of getrec(3), Note that the LOCKLEVEL must be 2 to enable this extra locking feature. A write lock is not required to be able to read a record. However, dbugen(1), dbrload(1) and dbmacro(1) all require write locks when modifying records.