Understanding Code Pages in Visual FoxPro

ID: Q129631

The information in this article applies to:

Microsoft Visual FoxPro for Windows, version 3.0

SUMMARY

This article discusses Code Pages in Visual FoxPro and covers the following topics:

Description of a Code Page.

How Visual FoxPro Uses Code Pages.

Using Code Pages in the Development Environment.

Checking for Code Page Marks in .DBF Files.

Entering Code Page Characters Not Represented by Keys on the Keyboard.

Using Code Pages from Earlier Versions of FoxPro.

Code Pages Supported by Visual FoxPro.

MORE INFORMATION

Description of a Code Page

A code page is a set of characters specific to a language or hardware platform. In Visual FoxPro, a code page is a table of characters and corresponding numbers in memory that Visual FoxPro uses to display data properly.

Some characters available in one code page are not available in another, and accented characters are not represented by the same values across platforms and code pages.

How Visual FoxPro Uses Code Pages

When you create a file with a table file structure, Visual FoxPro automatically gives it a code page mark, indicating which code page the file uses. For example, if you enter the letter C in a .DBF file, the letter is stored on your hard disk as the number 67. When you open the file, Visual FoxPro determines its code page, inspects the code page to find the character corresponding to the number 67, and then displays the character (C) on your monitor.

Using Code Pages in the Development Environment

Visual FoxPro supports many code pages and each code page contains characters unique to certain locales. If you want to create an application for a specific locale, you must create the application's components using the code page designed for that locale and environment. For example, to create an application for use in Russia, you should use code page 1251, 866, or 10007 for users in the Windows, MS-DOS, or Macintosh environments, respectively.

TIP: To create successive files with the same code page, first specify the code page by setting the CODEPAGE parameter in the CONFIG.FPW file. Then restart Visual FoxPro before creating the files.

Checking for Code Page Marks in .DBF Files

You can determine whether a .DBF file has a code page mark by using the CPDBF() function after opening the file or by having Visual FoxPro check when you open the file. To check for code page marks automatically:

From the Tools menu, choose Options.

Select the Data tab.

Set the Prompt for Code Page check box, if it is not already set.

To save this setting for future sessions of Visual FoxPro, choose Set as Default.

Entering Code Page Characters Not Represented by Keys on the Keyboard

If you need to enter characters not represented by keys on your keyboard, you must enter these characters using the ALT key in conjunction with keys on the numeric keypad. However, remember that the same key combination in different environments often displays different results. For example, if you enter ALT+0182 with code page 1252 in Visual FoxPro, you see a paragraph symbol. In contrast, if you enter ALT+0182 with code page 437 in FoxPro for MS-DOS, you see a graphic character with a double vertical line meeting a single horizontal line.

Using Code Pages from Earlier Versions of FoxPro

If you use a file from an earlier version of FoxPro, the file might not have a code page mark. If the mark is missing when you open the file, Visual FoxPro prompts you for a code page and then marks the file with it. However, if the code page is incorrect, some characters in the file might not display properly. If this happens, remove the code page mark, and then add the appropriate mark.

TIP: Instead of setting the Prompt for Code Page check box, you can use the SET CPDIALOG command to check for code pages.

Code Pages Supported by Visual FoxPro

Although Visual FoxPro supports many code pages, only a few are used often. With Visual FoxPro, for example, English-speaking users typically use code page 1252. However, with Visual FoxPro for MS-DOS, English-speaking users typically use code page 437. The following table shows the code pages supported in Visual FoxPro for each platform, and the corresponding code page identifier.


Code page      Platform                    Code page identifier
---------------------------------------------------------------
437            U.S. MS-DOS                 x01
620        (1) Mazovia (Polish) MS-DOS     x69
737        (1) Greek MS-DOS (437G)         x6A
850            International MS-DOS        x02
852            Eastern European MS-DOS     x64
861            Icelandic MS-DOS            x67
865            Nordic MS-DOS               x66
866            Russian MS-DOS              x65
895        (1) Kamenicky (Czech) MS-DOS    x68
857            Turkish MS-DOS              x6B
1250           Eastern European Windows    xC8
1251           Russian Windows             xC9
1252           Windows ANSI                x03
1253           Greek Windows               xCB
1254           Turkish Windows             xCA
10000          Standard Macintosh          x04
10006          Greek Macintosh             x98
10007      (1) Russian Macintosh           x96
10029          Macintosh EE                x97

NOTE: (1) This code page is not detected when you include CODEPAGE=AUTO in your configuration file.

REFERENCES

For more information about code pages, please see the "Understanding Code Pages" topic in the Visual FoxPro Help menu.

Additional query words: VFoxWin

Keywords : kbenv FxenvOptimize
Version : 3.00
Platform : WINDOWS
Issue type :