Compiling C in linux

cynosure · 20-07-2007, 08:48 PM

I am new to programming and am using an ebook to learn C.
I am crafting my first program i.e "Hello World"
I compiled the program using gcc and--like the ebook described--I compiled it correctly using "gcc -c Hello.c" and got a Hello.o file.
The ebook further said that if I use "gcc Hello.c" then I will get the linked form of the file. I used the same command and got an a.out file.
So my queries are:
1) How can I link an .o file directly using gcc or any other linker?
2) What exactly needs to be done with the a.out file?

mehulved · 21-07-2007, 11:19 AM

1)I don't think gcc is the linker. It's ld that you're looking for. Though you can link a library to your program by passing -l parameter to gcc

Code:

gcc Hello.c -lm

It will link math library.
Please correct me if I am wrong. I am not so proficient with these things.
2)execute it. It's the executable. You can give it your own name by passing -o parameter to gcc

Code:

gcc Hello.c -o Hello

That will create an executable Hello.
Check the pdf at http://people.ubuntu-in.org/~ghoseb/tc-to-gcc.pdf for more info. It's supposed to be for those people who come from tc to gcc. But, it is also very much helpful to those starting out with gcc, like me.

anantkhaitan · 21-07-2007, 12:40 PM

Yes for compiling C codes use:

Code:

$ gcc -W <filename.c> -o <executablename>

But various other parameters(specifying libraries etc) required if you include math.h and others
Run :

Code:

$ ./<executablename>

Also follow this .. http://anantkhaitan.googlepages.com/GCC.odt this is not my copied from somewhere..But still it is very helpful

cynosure · 21-07-2007, 09:14 PM

Thanks man, Let me try.

Garbage · 21-07-2007, 09:34 PM

THanx Mehul, That PDF is really nice.

gary4gar · 21-07-2007, 11:53 PM

Some good Guide that can teach you the basics of C???

mehulved · 22-07-2007, 12:03 AM

Quote:

Originally Posted by shirish_nagar

THanx Mehul, That PDF is really nice.

And the original author has encouraged people to share it and also add/correct information if possible.

~Phenom~ · 22-07-2007, 12:14 AM

and can anyone tell me how to run a java program in linux, without using any IDE like Eclipse as its too heavy and confusing ??

mehulved · 22-07-2007, 12:23 AM

As you'd do on cmd prompt on windows.

~Phenom~ · 22-07-2007, 12:34 AM

^^i tried it the same way long time ago , didnt worked . then also tried Eclipse , that too was too complex to understand and heavy too.
how to set those home variables , environment cariables , etc ?? I cudnt program succesfully in Linux thats the main reason , i Still have XP on my machine along with ubuntu.

PS: I successfully made and run a simple "print hello" program in linux in C using gcc , just for test purposes.

mehulved · 22-07-2007, 01:41 AM

Quote:

Originally Posted by ~Phenom~

^^i tried it the same way long time ago , didnt worked . then also tried Eclipse , that too was too complex to understand and heavy too.
how to set those home variables , environment cariables , etc ?? I cudnt program succesfully in Linux thats the main reason , i Still have XP on my machine along with ubuntu.

Is jdk installed?

Code:

sudo apt-get install sun-java6-jdk

paths are configured fine, no need to set it up, it's done automatically by package manager.

vish786 · 22-07-2007, 02:02 AM

Quote:

Originally Posted by mehulved

1)I don't think gcc is the linker. It's ld that you're looking for. Though you can link a library to your program by passing -l parameter to gcc

Code:

gcc Hello.c -lm

It will link math library.
Please correct me if I am wrong. I am not so proficient with these things.
2)execute it. It's the executable. You can give it your own name by passing -o parameter to gcc

Code:

gcc Hello.c -o Hello

That will create an executable Hello.
Check the pdf at http://people.ubuntu-in.org/~ghoseb/tc-to-gcc.pdf for more info. It's supposed to be for those people who come from tc to gcc. But, it is also very much helpful to those starting out with gcc, like me.

hey thanks for the pdf link... downloadin now