Noob C question (Multiple markers at this line)

[LoRd_MuldeR]

I have to do a project in C, but never used it before.
Just doing some very basic stuff for testing.

I got two files so far:

hello.c
#include "wurst.c"

int main(void)
{
murks();
return 0;
}

wurst.c

#include <stdio.h>

void murks(void)
{
printf("Hallo Welt!\n");
}

Problem:
It gives this error message in wurst.c

Multiple markers at this line:
- first defined here
- multiple definition of '_murks'

Thanks for any advice :D

[foxyshadis]

Your project probably includes both files. If it's VC, you can have the file in the project list but need to make it excluded from the build. If it's just a makefile, remove the reference to wurst.c.

Of course, the general preferred method is a header file that both can reference, instead of referencing one source inside the other, so both files can be compiled separately.

[LoRd_MuldeR]

Your project probably includes both files. If it's VC, you can have the file in the project list but need to make it excluded from the build. If it's just a makefile, remove the reference to wurst.c.

Of course, the general preferred method is a header file that both can reference, instead of referencing one source inside the other, so both files can be compiled separately.

I use Eclipse + CDT + Cygwin/GCC

So I'll have to learn how to use header files I guess ;)

[dancho]

My advice to you is try CodeBlock IDE (http://www.codeblocks.org/), he support large number of compilers...

And for your problem , you dont have to compile wurst.c file too,just hello.c file...

[LoRd_MuldeR]

My advice to you is try CodeBlock IDE (http://www.codeblocks.org/), he support large number of compilers...

And for your problem , you dont have to compile wurst.c file too,just hello.c file...

Thanks, but for the moment I'm happy I got Eclipse/CDT to work :D
Nevertheless I certainly will give CodeBlock a try...

[nfm]

#include "wurst.c" line in hello.c is not needed, compiler knows about all .c files in current dir where main() is. You do not need to compile wurst.c, only hello.c because it's where main() is. I found codeblocks to the best IDE I could work with on Linux. In Windows I use VS2005 because it's great. Here's an excellent tutorial from howstuff works http://computer.howstuffworks.com/c.htm

[LoRd_MuldeR]

Okay, I got CodeBlocks plus MinGW running now.
That seems to work fine for what I need to do at the moment...

[Manao]

The proper way of doing what you want to do is not to include wurst.c in hello.c. You also need to define the prototype of murks() in hello.c as follow :void murks();

int main()
{
...
}
If you were to use murks() in several different files, the next step would be to create a header that contains the prototype, and to include that header in the c files that need the function.

[LoRd_MuldeR]

Okay thanks! I think I understood how to use header files now ;)