一句话证明你

Shell

echo "hello world"

python 2.6 

print "hello,world"

Python 3.+


print ("hello,world")

C++ 

# include <ostream>
int main (void)
{
std::cout<<"hello world";
}

C 

# include <stdio.h>
int main (void)
{
printf ("\nhello world!")
return;
}

Java
public class helloworld {
// 程序的入口
public static void main (String args[]){
// 向控制台输出信息
System.out.println("hello world!");
}
}

Php

<?php
echo "hello world!";
?>

Ruby 

puts "hello world."

Go

package
import "fmt"
func main(){
fmt.Printf("hello world!\n God Bless You");

}