Question

我正在制作一个程序，让用户在运行程序时提供3位数字。如果它没有3个数字，那么我给出一条错误信息。如何测试数字的长度，以及如何将这些数字中的每个数字分配给变量？

提前感谢您的帮助！

我尝试过：grep '^[0-9][0-9][0-9]$'但这不起作用。

Answer 1

以下列为出发点。添加更多错误检查以获得练习。

#!/bin/bash

while : 
do
    read -p "Enter a three digit number or q to quit: " input
    if (( input >= 100 && input <= 999)); then 
        echo "good entry"
        digit1=${input:0:1} && echo "digit1 is $digit1"
        digit2=${input:1:1} && echo "digit2 is $digit2"
        digit3=${input:2:1} && echo "digit3 is $digit3"
    elif [[ $input == "q" ]]; then
        break
    else
        echo "bad entry"
    fi
done

输出：

Enter a three digit number or q to quit: 4256
bad entry
Enter a three digit number or q to quit: 242
good entry
digit1 is 2
digit2 is 4
digit3 is 2
Enter a three digit number or q to quit: 562
good entry
digit1 is 5
digit2 is 6
digit3 is 2
Enter a three digit number or q to quit: q
###program breaks here

Answer 2

您真的想为用户提交中的每个号码设一个变量吗？

ie - foo_one = 1，foo_two = 2，foo_three = 3？

或者你只是想迭代它们＆＃34;做某事＆＃34;与每一个？

这是我刚刚聚集在一起的东西，可以帮助你走上正轨：

#!/bin/bash

die() { printf "%s\n" "$@" 1>&2; exit 1; }

read -p "Enter 3 digit number " num

if [[ "${#num}" -lt 3 ]]; then
        die "Error: Please enter at least 3 digits."
else
        for (( i=0; i<${#num}; i++ )); do
                echo " var $i is ${num:$i:1}"
        done
fi

输出：

$ ./sotest.sh
Enter 3 digit number 123
var 0 is 1
var 1 is 2
var 2 is 3

很抱歉，如果这没有帮助。也许您可以提供有关总体目标的更多信息？

Answer 3

#!/bin/bash

userInput=$1

if [ $(grep -o "[0-9]" <<< $userInput | wc -l) -ne 3 ] || \
    [ $(grep -o "[a-z]" <<< $userInput | wc -l) -gt 0 ] || \
    [ $(grep -o "[A-Z]" <<< $userInput | wc -l) -gt 0 ]; then 
   echo "Provide exactly a 3-digit number. No letters, just Numbers..."; 
   exit 1;
else
   digi1=$(grep -o "[0-9]" <<< $userInput | awk 'NR==1{print}');
   digi2=$(grep -o "[0-9]" <<< $userInput | awk 'NR==2{print}');
   digi3=$(grep -o "[0-9]" <<< $userInput | awk 'NR==3{print}');

   echo "Digit-1 is $digi1";
   echo "Digit-2 is $digi2";
   echo "Digit-3 is $digi3";
fi

输出：

]$  ./test.bash 134
   Digit-1 is 1
   Digit-2 is 3
   Digit-3 is 4

我需要获取从参数输入的数字量并将它们分配给变量

3 个答案:

输出：