ch13.txt

前面我发的那本linuxprog的随书源代码

Chapter 13

-------------------------
Create a Display Function
-------------------------
function display
{
    echo "Welcome to the world"
    echo "of functions"
}

------------------
Calling a Function
------------------
#! /bin/bash
clear
function display
{
     echo "Welcome to the world"
     echo "of functions."
}
display

-------------------------------
Passing Arguments to a Function
-------------------------------
#! /bin/bash
clear
function verify
{
     if [ $1 -eq "Bob" ] && [ $2 -eq "555" ]
        then
          echo "Verified"
      else
          echo "Rejected"
fi
}
verify Bob 555

---------------------------------
Determine the Number of Arguments
Passed to a Function
---------------------------------
#! /bin/bash
clear
function verify
{
      if [ $# -ne 2 ]
         then
             echo "Wrong number of arguments!"
       else
           if [ $1 -eq "Bob" ] && [ $2 -eq "555" ]
              then
                echo "Verified"
          else
              echo "Rejected"
          fi
       fi
}
verify Bob 555

------------------------------------
Sharing a Function with a Subprogram
------------------------------------
#! /bin/bash
clear
function verify
{
      if [ $# -ne 2 ]
         then
             echo "Wrong number of arguments!"
       else
           if [ $1 -eq "Bob" ] && [ $2 -eq "555" ]
              then
                echo "Verified"
          else
              echo "Rejected"
          fi
       fi
}
export verify 
subprogram1

-------------------------------------
Returning Information from a Function
-------------------------------------
#! /bin/bash
clear
function verify
{
      if [ $# -ne 2 ]
         then
             return 1
      else
           if [ $1 -eq "Bob" ] && [ $2 -eq "555" ]
              then
                 return 0
              else
                 return 2
              echo "Rejected"
           fi
       fi
}
verify Bob 555
                        case $? in 
      0)
          echo "Verified"
           ;;
     1)
         echo "Wrong number of arguments!"
          ;;
      2)
          echo "Rejected"
           ;;
   esac