shell编程---printf函数

             printf函数使用规范

#! /bin/bash
#printf function  usage

function sum()
{
    let y=$1+$2
    echo $y
    return $?
}
echo "Welcome to shell script programming..."
#input two integer x,y
echo input two integer x,y
read x y
printf "x=%d,y=%d\n" $x $y
echo "exit $0 program.."