Emulate DOS/Windows Drive Letters like C: D: etc. in Linux

Unni2003 · 04-18-2009, 07:00 AM

I'm recompiling my Windows based software to Linux, and the drive letters are becoming a great hurdle.

Many files are accessed with their Drive letters in the program. For example, O:REPORT.TXT, F:\DATA\CUSTLIST.CSV etc.,

I'm able to recompile it perfectly in Linux. But I need to change everywhere the program is explicitly specifiying the path. If I change the path, then it will cease to work with Windows, unless it is controlled by an IF.

I'm not using Wine - my code has been natively compiled into Linux. So, other than changing my code, is there any way to 'emulate' drive letters in Linux?

Thanks.

XavierP · 04-18-2009, 08:42 AM

Well since the letters are pretty much a shortcut for /path/to why not switch the letters for the path to the file?

Nylex · 04-18-2009, 09:07 AM

Another thing you could do is save settings in a configuration file and then read that file when the program runs, using its' contents to set the relevant variables.

jiml8 · 04-18-2009, 09:27 AM

We luv symlinks. Lets you make drive letters whenever you need 'em.

Of course, that won't let you escape the linux path syntax vs the windows path syntax.

The way I handle code that gets compiled on multiple platforms (notably Windows and Linux) is like this:

First line of my C (or C++) file:

#include "target_platform.h"

If the target platform is Linux, target_platform.h contains this:

Code:

#ifndef LINUX_TARGET
#define LINUX_TARGET
#endif

If Windows, this:

Code:

#ifndef MS_WINDOWS_TARGET
#define MS_WINDOWS_TARGET
#include "windows.h"
#endif

Then, where it is relevant in my code, there are statements like this:

Code:

#ifdef MS_WINDOWS_TARGET
xsize=GetSystemMetrics(SM_CXSCREEN);
#endif
#ifdef LINUX_TARGET
xsize=gdk_screen_get_width(screen);
#endif

This way, you wind up with code that will compile on both platforms without difficulty.

Unni2003 · 04-19-2009, 08:43 AM

The codebase is pretty large, old and unstructured. (10+ years).. File names and paths are given as hard literals throughout the program (A few million lines+). I've been trying to locate a solution wherein the code would run without any change whatsoever.

But I guess I'll have to follow jiml8's advice. Thank you everyone.

janhe · 04-19-2009, 09:11 AM

I am not a developer, but not posting certainly won't help you:

I know you said you're not using wine, but wine is not only an emulator.
Winelib (http://winehq.org/docs/winelib-guide/index) is meant to help porting windows applications to linux.
You can find the guide in other formats here: http://winehq.org/documentation

maresmasb · 04-19-2009, 04:31 PM

Do this:
$ mkdir C:
$ mkdir C:\\

and you will get this
$ ls
C: C:\

Not a perfect solution actually, especially "C:\" and the backslash will become a pain in the a..

Conditional compilation makes more sense, like in jiml8's posting. You can pass define values to the code from the makefile by adding
-DMS_WINDOWS_TARGET
where MS_WINDOWS_TARGET is the definition