Example of a simple function in a shell script

This script my_name shows how the arguments to the function are passed, and how the function returns a value of TRUE or false. Use a parameter to invoke the script, which is the name you want to use in the problem.

Shell script code

#!/bin/shyes_or_no () {  echo "is your name $*?"  While true  does    echo-n "Enter Yes or no:"    read x Case    ' $x ' in      y | YES) return 0;;      n | No  ) return 1;;      *  )      echo "Answer Yes or no"      Esac   done}echo "Original parameters is $*" If Yes_or_no "$"  Then echo "Hi $1,nice name" Else  echo "Never Mind" Fiexit 0  

Test results

when the script starts, the function yes_or_no is defined, but it is not executed first. In the IF statement, when the script executes to function yes_or_no, first replace the first parameter of the program with Zhang, and then pass it as a parameter to the function. The function will use these parameters (they are now saved in a positional parameter of $, $) and return a value to the caller. The IF structure then executes the response statement according to the return value.

If statement in the shell, if Yes_or_no returns 0, then go to branch, and if return 1, go to Else branch.

Example of a simple function in a shell script