shell腳本應用（5）--實用腳本片斷

• 校驗參數

1. if [ "$#" -ne 1 ]
2. then
3. echo "Incorrect number of arguments"
4. echo "Usage: command arg1"
5. exit 1
6. fi

• 等待後臺程序執行完再繼續

1. prog1 &
2. #獲取prog1的pid
3. pid1 = $1
4. ...
5. #等待後臺prog1執行完繼續腳本
6. wait &pid

• 提示用戶輸入參數

1. #!/bin/bash
2. read -p "please type the password:" PW
3. echo $PW

• 更改登陸用戶密碼，懶得每次輸入新舊密碼

1. #!/bin/bash
2. (echo "curpw"; sleep 1; echo "newpw"; sleep 1; echo "newpw") | passwd

• ACM用測試數據檢驗程序正確與否

1. #！/bin/bash
2. while true
3. do
4. #生成隨機變量到input文件中,r能夠是生成腳本
5. ./r > input
6. ./a < input > output.a
7. ./b < input > output.b
8. diff output.a output.b
9. if [ $? -ne 0 ]
10. then
11. break
12. fi
13. done