shell 例程

一些经典的shell脚本例子

一。实现屏幕闪烁功能
#/bin/bash
clear
declare counter1=1
declare counter2

while [ "$counter1" -lt 1000 ]
        do
                echo "Warning: There's a bug in your program"
                let counter2=1
                while [ "$counter2" -lt 200 ]
                        do
                               let counter2="$counter2 + 1"
                done
                clear
                let counter2=1
                while [ "$counter2" -lt 200 ]
                        do
                                let counter2="$counter2 + 1"
                done
                let counter1="$counter1 + 1"
done

二。函数调用
#!/bin/bash
clear
function verify
{
        if [ $# -ne 2 ]
                then
                        echo "Wrong number of arguments!"
                else
                        if [ $1 == "Bob" ] && [ $2 == 555 ]
                                then
                                        return 0
                                else
                                        return 2
                        fi
        fi
}

verify Bob 555
case $? in
        0) echo "verified"
        ;;
        1) echo "Wrong number of arguments"
        ;;
        2) echo "Rejected"
        ;;
esac