的Bash shell腳本 - 返回鍵/回車鍵

Question

我需要比較我與輸入回車/返回關鍵...

read -n1 key 
if [ $key == "\n" ] 
    echo "@@@" 
fi 

但是這是行不通的。什麼是不對的代碼

Answer 1

發佈代碼的幾個問題。行內註釋詳細解決什麼：

#!/bin/bash 
# ^^ Bash, not sh, must be used for read options 

read -s -n 1 key # -s: do not echo input character. -n 1: read only 1 character (separate with space) 

# double brackets to test, single equals sign, empty string for just 'enter' in this case... 
# if [[ ... ]] is followed by semicolon and 'then' keyword 
if [[ $key = "" ]]; then 
    echo 'You pressed enter!' 
else 
    echo "You pressed '$key'" 
fi 

Answer 2

read從標準輸入讀取一行，直到但不包括行尾的新行。 -n指定最大字符數，如果達到該字符數，則迫使read提前返回。它仍然會提前結束，但當返回鍵被按下時。在這種情況下，它返回一個空字符串 - 一切都達到但不包括返回鍵。

您需要與空字符串進行比較以判斷用戶是否立即按下返回。

read -n1 KEY 
if [[ "$KEY" == "" ]] 
then 
    echo "@@@"; 
fi 

Answer 3

此外，它是不錯的主意定義進行比較之前空$ IFS（內部字段分隔符），否則你可以有「」，「\ n」等於結束。

因此，代碼應該是這樣的：

# for distinguishing " ", "\t" from "\n" 
IFS= 

read -n 1 key 
if [ "$key" = "" ]; then 
    echo "This was really Enter, not space, tab or something else" 
fi 

Answer 4

我添加以下代碼僅供參考，如果有人想使用含倒計時循環等解決方案。

IFS='' 
echo -e "Press [ENTER] to start Configuration..." 
for ((i=10; i>0; i--)); do 

printf "\rStarting in $i seconds..." 
read -s -N 1 -t 1 key 

if [ "$key" = $'\e' ]; then 
     echo -e "\n [ESC] Pressed" 
     break 
elif [ "$key" == $'\x0a' ] ;then 
     echo -e "\n [Enter] Pressed" 
     break 
fi 

done