擊：多個條件中，如果確認的參數

Question

因此，運行我的腳本，我使用的參數是這樣的：

./script 789 

的參數是改變文件或目錄的權限，和我倒要檢查是否每一個數字是0和7之間，所以我試圖爲未來的事情：

if [[ ${1:0:1} -ge 0 && ${1:0:1} -le 7 ]] && [[ ${1:1:1} -ge 0 && ${1:1:1} -le 7]] && [[ ${1:2:1} -ge 0 && ${1:2:1} -le 7]] 
then {go ahead with the code} 
else 
    echo "Error: each digit in the parameter must be between 0 and 7" 
fi 

如果這是真的，然後繼續用腳本，否則顯示錯誤信息，但它不」 t似乎工作。

Answer 1

您希望匹配參數與正則表達式[0-7][0-7][0-7]或[0-7]{3}。在bash中，你可以這樣做：

[[ "$1" =~ [0-7]{3} ]] || { echo 'invalid parameter' >&2; exit 1; } 

或者：

echo "$1" | grep -Eq '[0-7]{3}' || { echo err message >&2; exit 1; } 

Answer 2

，這可能是另一種方式

#!/bin/bash 

#Stored input parameter 1 in a variable 
perm="$1" 

#Checking if inserted parameter is empty, in that case the script will show a help 
if [ -z "${perm}" ];then 
     echo "Usage: $0 <permission>" 
     echo "I.e.: $0 777" 
     exit 
else 
     #if the parameter is not empy, check if each digit is between 0-7 
     check=`echo $perm| grep [0-7][0-7][0-7]` 
     #if the result of command is empty that means that the input parameter contains at least one digit that's differs from 0-7 
     if [ -z "${check}" ];then 
       echo "Error: each digit in the parameter must be between 0 and 7" 
     fi 
fi 

這就是輸出

[shell] ➤ ./test9.ksh 999 
Error: each digit in the parameter must be between 0 and 7 

[shell] ➤ ./test9.ksh 789 
Error: each digit in the parameter must be between 0 and 7 

[shell] ➤ ./test9.ksh 779 
Error: each digit in the parameter must be between 0 and 7 

[shell] ➤ ./test9.ksh 777