C/C++ program for linux

vi  add.c

#include<stdio.h>
int main()
{
int i, sum = 0;
for ( i = 1; i <= 3; i++ ) {
sum += i;
}
printf("sum = %d\n", sum);
return 0;
}

 save and quit

To Compile:
gcc -o add.out add.c

To Execute:
./add.out

Output
sum = 6