ch12.txt

平时学习linux总结的命令

Chapter 12

---------------------
Nested while for Loop
---------------------
let flag=1
while [ "$flag" -lt 4 ]
    do
             for friend in Bob Mary Sue
do
                 echo "Hello $friend ."
             done
                  let flag="$flag + 1"
done

-----------------
Nested while Loop
-----------------
let flag=1
while [ "$flag" -eq 1 ]
do
       for friend in Bob Mary Sue
          do
             echo "Hello $friend ."
             let  counter=1
              while [ "$counter" -lt 4 ]
                  do
                    echo "$friend"
                    let counter="$counter + 1"
               done
        done
        echo "Good-bye!"
        let flag=0
done

------------
Endless Loop
------------
let flag=1
while [ "$flag" -eq 1 ]
do
       for friend in Bob Mary Sue
          do
             echo "Hello $friend ."
             let  counter=1
              while [ "$counter" -lt 4 ]
                  do
                    echo "$friend"
                    let counter="$counter + 1"
               done
        done
        echo "Good-bye!"
        let flag=1
done

---------------------
Misplaced end Keyword
---------------------
let flag=1
while [  "$ flag" -eq 1 ]
   do
       for friend in Bob Mary Sue
          do
             echo "Hello $friend ."
             let counter=1
              while [ "$counter" -lt 4 ]
                   do
                     echo "$friend"
                     let counter="$counter + 1"
                      echo "Good-bye!"
                      let flag=0
               done
       done
done

-----------------
The break Keyword
-----------------
let n=1
while [ "$n" -eq 1 ]
   do
      echo "Enter your name or type stop to end: "
       read name 
       case $name in 
         "stop")
      break
       ;;
  esac
       echo "Good-bye!"
done

--------------------
The continue Keyword
--------------------
declare n=1
while [ $n -eq 1 ]
    do
        echo "Enter your name or type stop to end: "
        read name 
        echo "Enter your employee number:"
        read num
        case $name in
             "stop")
                    if [ "$num" -eq 1 ]
                        then
                           continue
                    else
                           break
                    fi
                  ;;
              *)
                   echo "Hello, $name"
          esac
done