Shell for while 循环

 li@ubuntu:~/test$ cat a.sh
 #!/bin/bash 

 for loop in 1 2 3 4 5
 do
     echo "The value is : $loop"
 done

 echo

 for str in 'This is a string '
 do
     echo $str
 done

 echo

 for file in $HOME/.bash*
 do
     echo $file
 done

 li@ubuntu:~/test$ ./a.sh
 The value is : 1
 The value is : 2
 The value is : 3
 The value is : 4
 The value is : 5

 This is a string

 /home/li/.bash_history
 /home/li/.bash_logout
 /home/li/.bashrc
 li@ubuntu:~/test$ 

while:

 li@ubuntu:~/test$ cat t.sh
 #!/bin/bash 

 while read number
 do
     echo "The number is $number"
 done
 li@ubuntu:~/test$ ./t.sh
 5
 The number is 5
 4
 The number is 4
 9
 The number is 9
 8
 The number is 8
 2
 The number is 2
 ^C
 li@ubuntu:~/test$