Review: xBASE Products for Linux
dBMAN functions primarily in interpretive mode, although it is possible to compile programs. (Compiling a program does not produce an executable binary; It produces a .run file, which still requires dBMAN to execute it.) When dBMAN starts up, a CMD: prompt appears at the top of the screen. At this point, you can type in ASSIST, which starts up a menu-driven interface similar to ones available with FoxPro or dBASE, but limited in comparison; dBMAN's ASSIST only allows one file to be open at a time, which in turn means that it is not possible to set up relations. It is possible to start up a simple program generator from ASSIST. Again, it has a single file limitation.
It is also possible to enter CREATE REPORT or MODIFY REPORT at the CMD: prompt. This will put you in dBMAN's report writer, which works very nicely. The report writer allows relations. I had a little bit of trouble getting it to write a report with lines wider than 80 columns, but I eventually got it to work.
dBMAN provides a function called PMENU() to create pull-down menus. PMENU doesn't have any mechanism for temporarily disabling a menu choice.
dBMAN handles windows differently from other xBASE products. Prior to defining a window, you call PUSHWIND() to push the current window onto a stack. (When a program is in its initial state, the entire screen is considered to be a window.) You then call WINDOW() to create the window. When you are finished with it, you call POPWIND(), which removes the window, and makes the previous window active.
dBMAN allows you to define only one hot key. You do so by invoking the ONKEY( ) function. This will have no effect until you execute the statement ON KEY statement. (statement will normally be DO hot-key-handler.)
The BROWSE Command has a long list of options. You can browse only certain fields, and you can specify the width of each field, and whether it is editable. The list of fields can include fields in other files, which is great if you have relationships set up.
dBMAN does not use either termcap or terminfo. Instead, it includes a file named dbmterm.dbm. It looks a lot like termcap. The first problem I had to solve after installing dBMAN was that there were no entries for either “xterm” or “console”.
I created one for color xterms without a whole lot of difficulty, and it is included in Listing 1.
dBMAN has no facility for executing functions written in C or assembler.
There were a couple of nasty bugs in the version of dBMAN I evaluated, which was 5.32. The main one was that procedure files simply didn't work if the procedure file was a .prg. If you compiled it into a .run file, it worked OK.
I put together a simple benchmark program, which can be found in Listing 2.
The test file I used contained 33,830 records. I ran the benchmark with dBMAN (compiled and non-compiled), FlagShip, and FoxPro 2.0 under MS-DOS. The benchmark was done on a 66MHz 486 with a SCSI disk. Here are the results. At first glance, you might conclude that both dBMAN and FlagShip were blown out of the water by FoxPro. This would be unfair. FoxPro generally beats similar MS-DOS products in benchmarks, because FoxPro, by design, grabs all resources it can find. No well-behaved Linux program would do this. To put it another way, dBMAN and FlagShip would run a lot faster if they allocated most of the 16 megabytes of memory on my machine, but someone doing text editing on another terminal would see their performance suffer.
xBASE files always have separate data (.dbf) and index files. The format of data files is pretty much uniform for all xBASEs, but as far as I know, no two xBASE products use the same index file formats. I was able to use the same .dbf files with FlagShip and dBMAN, but I haven't tried any memo fields yet. (Memo fields put free-form text into a separate file, usually with the .dbt extension.)
|Making Linux and Android Get Along (It's Not as Hard as It Sounds)||May 16, 2013|
|Drupal Is a Framework: Why Everyone Needs to Understand This||May 15, 2013|
|Home, My Backup Data Center||May 13, 2013|
|Non-Linux FOSS: Seashore||May 10, 2013|
|Trying to Tame the Tablet||May 08, 2013|
|Dart: a New Web Programming Experience||May 07, 2013|
- RSS Feeds
- Making Linux and Android Get Along (It's Not as Hard as It Sounds)
- New Products
- Drupal Is a Framework: Why Everyone Needs to Understand This
- A Topic for Discussion - Open Source Feature-Richness?
- Home, My Backup Data Center
- Validate an E-Mail Address with PHP, the Right Way
- New Products
- Developer Poll
- Why Python?
- not living upto the mobile revolution
2 hours 11 min ago
- Deceptive Advertising and
2 hours 47 min ago
- Let\'s declare that you have
2 hours 48 min ago
- Alterations in Contest Due
2 hours 49 min ago
- At a numbers mindset, your
2 hours 50 min ago
- Do not get Just Almost any
2 hours 54 min ago
- A fantastic rule-of-thumb to
2 hours 55 min ago
- Keren mastah..
3 hours 53 min ago
- mini tablet compare
5 hours 12 min ago
- Looking Good
8 hours 45 min ago
Enter to Win an Adafruit Prototyping Pi Plate Kit for Raspberry Pi
It's Raspberry Pi month at Linux Journal. Each week in May, Adafruit will be giving away a Pi-related prize to a lucky, randomly drawn LJ reader. Winners will be announced weekly.
Fill out the fields below to enter to win this week's prize-- a Prototyping Pi Plate Kit for Raspberry Pi.
Congratulations to our winners so far:
- 5-8-13, Pi Starter Pack: Jack Davis
- 5-15-13, Pi Model B 512MB RAM: Patrick Dunn
- Next winner announced on 5-21-13!
Free Webinar: Linux Backup and Recovery
Most companies incorporate backup procedures for critical data, which can be restored quickly if a loss occurs. However, fewer companies are prepared for catastrophic system failures, in which they lose all data, the entire operating system, applications, settings, patches and more, reducing their system(s) to “bare metal.” After all, before data can be restored to a system, there must be a system to restore it to.
In this one hour webinar, learn how to enhance your existing backup strategies for better disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible bare-metal recovery solution for UNIX and Linux systems.