problem compiling c program

[owen76]

With everyone's help I finally got my first linux installation working. I hadn't programmed in c in two years, so anxious to get started. I typed in my starter program in pico.

#include<stdio.h>

void main()
{
printf("hello");
}

I then compiled hello.c:

gcc hello.c

It spewed back an error message, something about main not being int.

What am I doing wrong? Thanks for your help!

[pwaring]

You need to change the line: 'void main()' to 'int main()' (without the quotes). This defines the main() function as returning an integer value.

You should also add the line 'return 0;' (again without the quotes) after 'printf("Hello");

A properly working example is shown below:

/* hello.c */

#include <stdio.h>

int main()
{
printf("Hello");
return 0;
}

/* end hello.c */

This should compile properly under any ASCII compliant C compiler (including gcc).

Hope this helps.

[PainShock]

Probre in this form:
/* --------------- Begin code ----------------- */
#include<stdio.h>
main()
{
printf("Hello World\n");
}
/* -------------- End code -------------------- */

You also can put at this form

/* --------------- Begin code ----------------- */
#include<stdio.h>
main()
{
system("clear"); /* With this line when the program run first
clean the screen and next put Hello Worl. With the system you can put commands of the OS like ls, cat .... */
printf("Hello World\n");
}
/* -------------- End code -------------------- */
To compile you can put of this form:
gcc -o hello hello.c
The option -o is to put name that you want to have the exit program
Bye and lucky programing bye

[owen76]

Maybe I'm doing something wrong, but I tried the first approach and got an error message about printf not being recognized.

I tried gcc -c , to stop after compiling, but before linking, and manually linked with ld. That's when I got the error message. The message wouldn't show up
with just gcc. It is quite frustrating. I want to like the thing.

[l3aDmOnKeY]

// little help

#include <stdio.h>

int main()

{
printf ("Hello World\n");

return 0;

}

[Vorlin]

Let's see here, compilers..woo!

#include <stdio.h>

int main() {
printf("Hello world!\n");
}

That's all you need, say, in a foo.c file, of which then we do this:

$ gcc foo.c -o foo

You should have a file called 'foo' now, fully executable and ready to run. That's all that really needs to be done. By the way, the term 'void' means you don't require anything to be returned to you whereas 'int' means the result will be an integer value. Boolean means a true or false, etc etc...

[PainShock]

Send your code to see how is your program and if see some bug i can tell you bye

[owen76]

OK, this is a REALLY stupid question, but just typing foo at command prompt would run the program? Mine has that color coded thing going on so when the name is green, I should be executable?

[rcgreen]

That's ./filename unless the current directory
is on the PATH.
Unlike DOS, Linux doesn't execute programs
located in the current directory by default.

[Terr]

Originally posted by owen76
OK, this is a REALLY stupid question, but just typing foo at command prompt would run the program? Mine has that color coded thing going on so when the name is green, I should be executable?

So you're using the "ls --color" option (or equivalent) as an alias?

Just BTW folks, you can use the "php" tags in the forum, which causes auto-formatting and color coding. (The "code" tags preserve original formatting.) For example (from Painshock's Post #3)

/* --------------- Begin code ----------------- */
#include<stdio.h>
main()
{
system("clear"); /* With this line when the program run first 
clean the screen and next put Hello Worl. With the system you can put commands of the OS like ls, cat .... */
printf("Hello World\n");
}
/* -------------- End code -------------------- */