键入期间的Bash输入验证

Question

我正在编写Bash脚本，要求您只输入数字。如何防止在输入数字时显示非数字？例如，如果我在提示符下键入123ab45c6，则屏幕上只会显示123456。

Answer 1

#/bin/bash
echo "Please enter a number"
# variable to store the input
number=""
# reading in silent mode character by character
while read -s -n 1 c
do
    case $c in
    [0-9]) 
        # if the read character is digit add it to the number and print the number
        number="${number}${c}"
        echo -en "\r${number}"
        ;;      
    '') 
        # break on ENTER
        echo    
        break;; 
    esac
done
echo "You entered a number ${number}"