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Porting C programs from Windows to Unix?

Dave, I read your books Teach Yourself Unix in 24 Hours and Wicked Cool Shell Scripts and since then I can't imagine working again on a system like windows!

My problem is that I've started to make my C files Unix-compatible but I can't find a command for C in Windows that does the same thing as system("cmd") for Unix. Any suggestions?

Dave's Answer:

This was a tough question, actually, because I haven't done any Windows-level C programming in, well, more years than I want to talk about. Let's just say it's been a rather long time. :-)

I do remember that the wonderful Unix system() call that makes it a breeze to invoke any other Unix command (or sequence of commands) from within a C program has no direct analog in the Windows programming world because of the fundamental differences in OS architecture.

To figure out how to best address this, I asked a couple of colleagues who are better versed in C / Windows programming, and here's what they had to say:

The system function executes an internal operating system command, or an .EXE, .COM (.CMD in Windows NT) or .BAT file from within a C program rather than from the command line.

The system function finds the command interpreter, which is typically CMD.EXE in the Windows NT operating system or COMMAND.COM

Your options for an analog to the Unix system call depend on how much work you want to undertake, and what you want to achieve. For total control, use the CreateProcess system call. It is low level, closer to the fork/exec level in UNIX. WinExec is a higher level function that is closer to system. You can also call system, but you have no control over console windows, window states, etc.

I hope those are helpful to you. If I bump into a better or more definitive answer, I'll post it as a comment, and, of course, it's quite possible that some other reader might have a better response that they can add here too!

Thanks to Ray Lischner, JP Morgenthal and Wayne Freeze for their assistance

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Categorized: Unix and Linux Help , Windows Help (Article 3944)
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Comments

Something is not very clear to me.
You are converting Windows C programs to Unix and want to know about how to implement a certain C functionality of Unix in the Windows environment.
Isn't that the other way around?

Posted by: Martin at April 2, 2005 2:09 PM

I kinda wondered about that myself, Martin. My conclusion is that he's trying to convert his C programs within the Windows environment before he ports them to Unix.

Posted by: Dave Taylor at April 2, 2005 2:57 PM

Another possibility is that he's looking for the shell command ("cmd" in Windows) which, depending on the shells available will be one of "sh", "csh", "ksh", "tcsh", etc. (Bourne, C-Shell, Korn, etc)

This matches the example that was provided.
Hope this helps.

Posted by: Todd at April 11, 2005 4:54 PM

I have existing GUI SDK/C program in windows.
How can I port to unix environment specially to solaris and linux.
Can you please guide me if you have any examples or tool available which do the same things.

Thanks
BPM

Posted by: BPM at July 1, 2005 9:20 PM

i have a c program which is running under linux operating system . i wish to run the same c program under windows operating system

what the steps i need to follow to run the same c code on windows platform .

i am using windows xp

the program is connecting the medical device to pc and reading the data onto the server

thanks
capry

Posted by: capry at August 28, 2007 8:53 PM

i have c program which is running on linux operating system want to run on windows operating system

the program is successfully executing the code on linux operating system

steps to follow is fine enough

thanks
capry

Posted by: capry at August 28, 2007 9:02 PM

i have c program which is running on linux operating system want to run on windows operating system

the program is successfully executing the code on linux operating system

steps to follow is fine enough

thanks
capry

Posted by: capry at August 28, 2007 9:04 PM

Hello Dave and Team.
First off, I'd like to say thanks and congrats for all the help and info you and your team has/are providing for everyone to benefit freely. Sites such as this are, hummmm, lacking more and more to say the least. And I for one, really apreciate it all.

In the past I've found many helpful articles on this site, nad have past along the wealth to many friends. I don't really have a technical question per-say, but more along the lines of looking for an opinion. Some time ago I found another project I'd like to have your thoughts on. UNIX's WINE project have started some time ago a new project called ReactOS, for a new Operating System. You can find it @: www.reactos.org

I'd be currious to read your thoughts on the project, if of course your time allows it.

Thx muchly in advance for your time and thoughts on the matter.

Cheers, and keep up the great work.
Marc.

PS: When I complete my website, I'll most certainly add a link to yours.

Posted by: Marc at November 9, 2007 7:37 PM

I have linux c file which uses "system(cmdline)" and now I need to port it to Windows VC/C++.
How could I do it?

Thanks

Barbara

Posted by: Barbara Shi at January 9, 2008 3:01 PM

i have c program which is running on linux operating system want to run on windows operating system

the program is successfully executing the code on linux operating system

Posted by: vipul patel at February 27, 2008 12:11 AM

I have a lot to say, but ...

I have a lot to say, and questions of my own for that matter, but most of all I'd like to say thank you for all your efforts on this Web site by buying you a chai!

I do have a comment, now that you mention it!