Unix的循環變量

Question

我需要你在下面確定我的問題的幫助，

我的目的是循環值的輸入，而在同一時間檢查輸入值，如果其[0-9]，然後將其保存到一個文件然後對它的輸出進行排序。

我的問題是，每當我運行腳本，值保留爲1 2 3 4 5不是我輸入的那個，你能幫助我嗎？我認爲在條件語句中的變量聲明中存在問題，但我不知道任何解決方法。

#!/bin/bash -x 

echo > save.txt 
validnum='0-9' 

    for ((i=1;i<=5;i++)) 
    do 
    read -p "Please enter number $i: " num_$i 
    if [[ ! $num_$i =~ [^$validnum$] ]] && [[ $num_$i == "" ]] 
    then 
      echo "Input numbers have been validated.." 
      echo $num_$i >> save.txt 
    else 
      echo "INVALID CHARACTERS IDENTIFIED.." 
      echo "Please review your Input Values" 
      exit 0 
    fi 
done 
echo "Sorting values.." 
echo "Below are the sorted values" 
echo `cat save.txt | sort -n` 

這裏是每當我運行腳本時的擴展版本。

+ echo 
+ validnum=0-9 
+ ((i=1)) 
+ ((i<=5)) 
+ read -p 'Please enter number 1: ' num_1 
Please enter number 1: 
+ [[ ! 1 =~ [^0-9$] ]] 
+ [[ ! 1 == '' ]] 
+ echo 'Input numbers have been validated..' 
Input numbers have been validated.. 
+ echo 1 
+ ((i++)) 
+ ((i<=5)) 
+ read -p 'Please enter number 2: ' num_2 
Please enter number 2: 
+ [[ ! 2 =~ [^0-9$] ]] 
+ [[ ! 2 == '' ]] 
+ echo 'Input numbers have been validated..' 
Input numbers have been validated.. 
+ echo 2 
+ ((i++)) 
+ ((i<=5)) 
+ read -p 'Please enter number 3: ' num_3 
Please enter number 3: 
+ [[ ! 3 =~ [^0-9$] ]] 
+ [[ ! 3 == '' ]] 
+ echo 'Input numbers have been validated..' 
Input numbers have been validated.. 
+ echo 3 
+ ((i++)) 
+ ((i<=5)) 
+ read -p 'Please enter number 4: ' num_4 
Please enter number 4: 
+ [[ ! 4 =~ [^0-9$] ]] 
+ [[ ! 4 == '' ]] 
+ echo 'Input numbers have been validated..' 
Input numbers have been validated.. 
+ echo 4 
+ ((i++)) 
+ ((i<=5)) 
+ read -p 'Please enter number 5: ' num_5 
Please enter number 5: 
+ [[ ! 5 =~ [^0-9$] ]] 
+ [[ ! 5 == '' ]] 
+ echo 'Input numbers have been validated..' 
Input numbers have been validated.. 
+ echo 5 
+ ((i++)) 
+ ((i<=5)) 
+ echo 'Sorting values..' 
Sorting values.. 
+ echo 'Below are the sorted values' 
Below are the sorted values 
++ cat save.txt 
++ sort -n 
+ echo 1 2 3 4 5 
1 2 3 4 5 

Answer 1

我想你只需要下面

validnum='[0-9]' 

read -p "Please enter number $i: " num 

if [[ $num =~ ^$validnum{1}$ ]]; then 
# rest of the code 

到單位來自0-9匹配。請記住，我已將變量validnum內的括號表達式移動到可讀的以上。將此片段插入代碼應該可以解決您的問題。

正如在評論中所討論的那樣，你不需要爲你的這個需求使用動態變量。

---

OP曾要求正則表達式的解釋，

RegEx demo

從上述正則表達式頁面引用，說明正則表達式^[0-9]{1}$

^字符串的開始斷言位置

匹配列表中存在的單個字符下面[0-9]{1}

{1}量詞 - 恰好匹配一個時間（無意義量詞）

0-9 在0 (ASCII 48)和9 (ASCII 57)（區分大小寫）之間的範圍中的單個字符

$在字符串的結束時聲明位置，或在字符串末尾的行結束符之前