ch19.txt

平时学习linux总结的命令

Chapter 19

--------------------------
Setting Flags to Trap Bugs
--------------------------
#!/bin/bash
let flag=1
echo "Outside of while loop"
while [ "$flag" -eq 1 ]
   do
      echo "inside of while loop"
       for friend in Bob Mary Sue
          do
            echo "inside of for in loop"
            echo "Hello $friend." 
       done
    echo "outside of foreach loop"
    echo "Good-bye!"
    let flag=1
    echo "last line in while loop"
done
echo "last line in the program"

---------------------
Display Hidden Values
---------------------
#!/bin/bash
let flag=1
echo "Outside of while loop flag = $flag"
while [ "$flag" -eq 1 ]
   do
       echo "inside of while loop flag = $flag "
       for friend in Bob Mary Sue
          do
            echo "inside of foreach loop flag = $flag "
            echo "Hello $friend."
       done
     echo "outside of foreach loop flag = $flag "
      echo "Good-bye!"
  let flag=1
   echo "last line in while loop flag = $flag "
done
echo "last line in the program flag = $flag "