first program in c not working

[phopogologo]

I installed gcc from the apt-get package system and found a website that showed me how to write and run my first c program. The program is just this:

#include <stdio.h>

main()
{
printf("Hello, world!\n");
return 0;
}

which I doubt has many errors, but here's my problem. Once I start up a gnome-terminal and writes:

$ gcc hello.c

it prompts this:

hello.c:1:19: error: stdio.h: No such file or directory
hello.c: In function ‘main’:
hello.c:5: warning: incompatible implicit declaration of built-in function ‘printf’

gcc is located at /usr/bin/gcc if that is of any help..

[Franklin52]

Hi,

You have to install libc6-dev.

Regards

[Zelmo]

Check that you have the libc-dev or libc6-dev package (or something similar) installed.

[devils casper]

Execute this

sudo apt-get install build-essential

It will install all necessary packages including libc6-dev and linux-libc-dev.

[phopogologo]

I installed the libc6-dev, and now it does not prompt an error message when I write "gcc hello.c", now it does nothing, which is, gives no output.

[phopogologo]

I also installed build-essentials, but the result is still the same. Could there be something wrong with the program?

[daark.child]

There should be a file called a.out in the directory where you are compiling your apps. You can run it by doing

./a.out

If you want your program to have the same name as your file (or any other name for that matter) instead of a.out, you need to do

$gcc -o someprog someprog.c

Your main function should also have a return type, so your code should be something like

#include <stdio.h>

int main(void)
{
    printf("Hello, world!\n");
    return 0;
}

[phopogologo]

./a.out prints "hello, world". Will this file always show my output and is it necessary to access the output through it?

[infoshirish]

Hey,
No need to include <stdio.h> in linux. Your program should be like this.

# cat hello.c
main ()
{
printf("Hello World");
}
# make hello
# cc hello.c -o hello
Or
#./hello.c
Will also throw your output.

[techieMoe]

Hey,
No need to include <stdio.h> in linux. Your program should be like this.

# cat hello.c
main ()
{
printf("Hello World");
}
# make hello
# cc hello.c -o hello
Or
#./hello.c
Will also throw your output.

I would not recommend this procedure. ANSI standard C requires includes and return values. You're cutting corners by not returning a status at the end of your program and that's just bad practice.

In my work I've never seen a standard C program that used the above method, so although it may work in theory, I cannot recommend that a new programmer learn a non-standard method that will only lead to confusion later on.