total newb

[Sophie1986]

A couple of days ago I decided to try and make some programs in C.
I've never used any non interpreted language before (and even then my experience is pretty minimal).

What I am wondering though is, so far if I compile something on one of my computers (one has fedora, the other has gentoo), it doesn't run on the other one. I kind of expected that. One of them is 32bit and the other 64bit for one thing. And on gentoo I put march native in my make.conf.

But I gather it must be possible to compile things that work on various computers, otherwise you wouldn't be able to download binaries and run them on most ordinary PC's.

So how do you go about it? Is there somewhere where you can make once off choices to compile something very generically (since generally I wouldn't be compiling stuff to use it on both computers, and even now with the 3 line programs I am writing its not exactly a big deal, I am really just curious)?

And I suppose generally if I were going to do that I'd have to compile it on the 32bit computer then it can be used on both? But it won't work the other way round? Or am I wrong?

[Hlingler]

But I gather it must be possible to compile things that work on various computers, otherwise you wouldn't be able to download binaries and run them on most ordinary PC's.

The details are definitely out of my league, but as general info: many "generic" 3rd-party binaries (e.g.: NVidia & ATI binary "blobs") are actually executable installation scripts created with makeself or equivalent, and many also include [customized/static] support libraries, all to make them more "generic" (i.e.: for use on many different Linux distros). Most also come in both 32-bit and/or 64-bit flavors. Many/most also require compilers and kernel-devel or equivalent to build/install, especially if kmods are to be built.

And I suppose generally if I were going to do that I'd have to compile it on the 32bit computer then it can be used on both? But it won't work the other way round? Or am I wrong?

You are correct. Note however that on the 64-bit OS, the appropriate 32-bit support libraries must be available/installed.

HTH,
V

[Sophie1986]

Originally Posted by Hlingler

The details are definitely out of my league, but as general info: many "generic" 3rd-party binaries (e.g.: NVidia & ATI binary "blobs") are actually executable installation scripts created with makeself or equivalent, and many also include [customized/static] support libraries, all to make them more "generic". Most also come in both 32-bit and/or 64-bit flavors. Many/most also require compilers and kernel-devel or equivalent to build/install, especially if kmods are to be built.

HTH,
V

Ah, that's interesting to know.

[alwinl]

Good on you to expand your experience.

Little tip, 'ldd' is your friend, read the man page. Every time a program does not want to start for whatever reason, run 'ldd' to see if all needed libraries are installed and are version compatible. Run 'ldd' on both computers to see where the differences are.

'ldd' should be installed on a system if you have loaded compilers and such like but just in case it's not in Fedora its provided by the glibc-common package.

Good luck


Alwin

[arifwn]

Try to statically link your program so it can run on any distro regardless of library's availability.

[tux4me]

That is exactly how i would do it too.
When you compile statically, all needed libraries get included in your executable.
You get a bigger binary, a lot bigger, (compared) but it runs faster and is more portable.
But you have to recompile it every time the libs gets updated, if you want to use the new libs.