compile the file hello_world with gcc

For programs with a single source file, using gcc is simple.

/* File name is hello_world.c */
#include <stdio.h>

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

To compile the file hello_world.c from the command line:

gcc hello_world.c

gcc will then compile program and output the executable to the file a.out. If you want to name the executable, use the -o option.

gcc hello_world.c -o hello_world

The executable will then be named hello_world instead of a.out. By default, there are not that many warnings that are emitted by gcc. gcc has many warning options and it is a good idea to look through the gcc documentation to learn what is available. Using '-Wall' is a good starting point and covers many common problems.

gcc -Wall hello_world.c -o hello_world