Shell 在while read循环中读取密钥失败

这是我的脚本，用于检测按下的键：

#!/bin/bash
echo "Reading keys."
while [ "x$keypress" = "x" ]; do
  read -n 1 -t 1 -s keypress
  printf "."
done
printf "\n"
echo "Pressed key: "$keypress

这似乎工作正常（例如，过一会儿按“q”键）：

但是，如果我将其放入一个循环中，该循环读取我的

File.txt

，并等待每一行的键：

#!/bin/bash
MyList=File.txt
while IFS=, read -ra ListLine
do
    echo "Processing line: "$ListLine
    echo "Press [S] to count as Secret or [P] to count as Public."
  while [ "x$keypress" = "x" ]; do
        read -n 1 -t 1 -s keypress
    printf "."
    done
    printf "\n"
    echo "Pressed key: "$keypress
done < "$MyList"

这是

文件.txt

内容：

d:\Temp
c:\Temp
e:\Temp 

---

我在某个地方读到，问题来自

，它在第一次循环后工作，因为keypress是空的，但在随后的调用中，keypress仍然设置为在第一次循环中设置的值。
您只需将keypress变量设置为空字符串。
您可以从不同的文件描述符读取，并重构内部循环

while IFS=, read -r -u 3 -a ListLine
do
  echo 'Processing line:' "$ListLine"
  echo 'Press [S] to count as Secret or [P] to count as Public.'
  until read -n 1 -t 1 -s keypress
  do
    printf .
  done
  echo
  echo 'Pressed key:' $keypress
done 3< File.txt

当IFS=，读取-r-u3-a列表行
做
回显“处理行：”“$ListLine”
echo'按[S]算作机密，或按[P]算作公共。'
直到读到-n1-t1-s键为止
做
printf。
完成
回声
echo“按下键：”$keypress
完成3

Mmm。。我正在测试，你似乎是对的，克劳迪奥。谢谢你。您应该编辑您的答案，以增强它，以符合论坛规则。至少，我认为您必须添加一个示例（只需对我的脚本进行简单的修改就足够了）。谢谢。你的脚本似乎有一些小的修改，但我认为它是正确的。请注意，
whileifs=，read-r-u3-a ListLine
和
whileifs=，read-ra ListLine
d:\Temp
c:\Temp
e:\Temp 

#!/bin/bash
MyList=File.txt
while IFS=, read -ra ListLine <&3
do
    echo "Processing line: "$ListLine
    echo "Press [S] to count as Secret or [P] to count as Public."
  while [ "x$keypress" = "x" ]; do
        read -n 1 -t 1 -s keypress
    printf "."
    done
    printf "\n"
    echo "Pressed key: "$keypress
done 3< "$MyList"

$ ./prueba07.sh
Processing line: d:\Temp
Press [S] to count as Secret or [P] to count as Public.
..
Pressed key: p
Processing line: c:\Temp
Press [S] to count as Secret or [P] to count as Public.

Pressed key: p
Processing line: e:\Temp
Press [S] to count as Secret or [P] to count as Public.

Pressed key: p
Processing line:
Press [S] to count as Secret or [P] to count as Public.

Pressed key: p

read -n 1 -t 1 -s keypress </dev/tty

#!/bin/bash
MyList=File.txt
while IFS=, read -ra ListLine <&3
do
    echo "Processing line: "$ListLine
    echo "Press [S] to count as Secret or [P] to count as Public."
  while [ "x$keypress" = "x" ]; do
        read -n 1 -t 1 -s keypress
    printf "."
    done
    printf "\n"
    echo "Pressed key: "$keypress
    unset keypress
done 3< "$MyList"

while IFS=, read -r -u 3 -a ListLine
do
  echo 'Processing line:' "$ListLine"
  echo 'Press [S] to count as Secret or [P] to count as Public.'
  until read -n 1 -t 1 -s keypress
  do
    printf .
  done
  echo
  echo 'Pressed key:' $keypress
done 3< File.txt