64 bit Windows/Linux Compilation

[egrobler]

Hallo Lazarus community,

I am new to Lazarus and I want to create a 64-bit search engine that will run either in windows or linux.
I just compiled my first win64 "hallo world" application and it reports the SizeOf(Pointer) as 8 bytes, so I am happy!

I would just like some pointers regarding the following:
- I assume that I need to compile the same code in a 64 bit linux OS to compile "cross platform"?
- What tcp/ip library should I use with Lazarus (I just need basic functionality)
- Is there a good guide on how to write portable code (linux/windows) in Free Pascal?

Thanks in advance
Eric

[skalogryz]

- Is there a good guide on how to write portable code (linux/windows) in Free Pascal?

http://wiki.lazarus.freepascal.org/Writing_portable_code_regarding_the_processor_architecture

[egrobler]

- Is there a good guide on how to write portable code (linux/windows) in Free Pascal?

http://wiki.lazarus.freepascal.org/Writing_portable_code_regarding_the_processor_architecture

Thanks skalogryyz,

I actually did come across that article.
If that is all I need to be concerned about then I am impressed - seems very easy!

But are all lazarus libraries 64-bit aware and works under all platforms?
What about visual controls?

Thanks and regards
Eric

[skalogryz]

But are all lazarus libraries 64-bit aware and works under all platforms?
What about visual controls?

If you find any library or control, that doesn't work under 64-bit, then you need to report it as a bug at the mantis: bugs.freepascal.org

There were some 64-bit compatibility issues, but most of them have been fixed, in the mean time.

Carbon (MacOSX) library is 32-bit only, because of Apple limitations.

[egrobler]

But are all lazarus libraries 64-bit aware and works under all platforms?
What about visual controls?

If you find any library or control, that doesn't work under 64-bit, then you need to report it as a bug at the mantis: bugs.freepascal.org

There were some 64-bit compatibility issues, but most of them have been fixed, in the mean time.

Carbon (MacOSX) library is 32-bit only, because of Apple limitations.

Ok, thanks for the fast feedback.

Have a nice day
Eric

[alter]

- I assume that I need to compile the same code in a 64 bit linux OS to compile "cross platform"?

It's not that simple. Or actually it is if you remember about some differences in those systems. For instance Windows uses "\" in file paths while Linux uses "/". Neither Lazarus nor fpc will handle this so it is developer who must do that.

- What tcp/ip library should I use with Lazarus (I just need basic functionality)

Synapse or Indy. Both are working with Linux

[egrobler]

It's not that simple. Or actually it is if you remember about some differences in those systems. For instance Windows uses "\" in file paths while Linux uses "/". Neither Lazarus nor fpc will handle this so it is developer who must do that.

Thanks for the feedback, is there a compiler directive I can use to determine if it is linux or windows?

Regards
Eric


Edit: fixed quote tag.

[alter]

It's not that simple. Or actually it is if you remember about some differences in those systems. For instance Windows uses "\" in file paths while Linux uses "/". Neither Lazarus nor fpc will handle this so it is developer who must do that.

Thanks for the feedback, is there a compiler directive I can use to determine if it is linux or windows?

Regards
Eric
[/quote]
{$IFDEF WINDOWS}
your Windows code
{$ELSE}
code for Linux
{$ENDIF}

instead of WINDOWS you can also use LINUX of course

[egrobler]

{$IFDEF WINDOWS}
your Windows code
{$ELSE}
code for Linux
{$ENDIF}

instead of WINDOWS you can also use LINUX of course

Thanks!

[theo]

It's not that simple. Or actually it is if you remember about some differences in those systems. For instance Windows uses "\" in file paths while Linux uses "/". Neither Lazarus nor fpc will handle this so it is developer who must do that.

But you can use the consts "PathDelim" or "LineEnding" instead which are OS aware.

[egrobler]

But you can use the consts "PathDelim" or "LineEnding" instead which are OS aware.

Thanks Theo, that is good to know...

[alter]

It's not that simple. Or actually it is if you remember about some differences in those systems. For instance Windows uses "\" in file paths while Linux uses "/". Neither Lazarus nor fpc will handle this so it is developer who must do that.

But you can use the consts "PathDelim" or "LineEnding" instead which are OS aware.

Those are constants. What with situation that for example someone generates some file path using Windows version (that is supposed to contain"/" so Windows version can process it properly) and then you export this string for example to file. Later you need to process it with Linux version so you can access some file with Linux version. Of course if given string we are talking about contains absolute path then there is no point but if it contains relative one it must be handled. And here is where platform specific code comes.

[Vincent Snijders]

And then it can be handled Platform independent using several SysUtils functions, for example SetDirSeparators.

[alter]

And since for example TFileStream doesn't call it you must call it manually before providing file path to TFileStream or actually at least most common classes using it such as TStringList for example