如何在bash中读取文件*和*stdin

Question

这是我的任务:逐行从文件中读取一些数据.对于每一行,如果它满足某些条件,则要求用户输入内容并根据用户的输入继续.

我知道如何从shell脚本逐行阅读内容:

while read line; do
   echo $line
done < file.txt

但是,如果我想做什么与用户交互的内部循环体.从概念上讲,这就是我想要的:

while read line; do
    echo "Is this what you want: $line [Y]es/[n]o"
    # Here is the problem:
    # I want to read something from standard input here.
    # However, inside the loop body, the standard input is redirected to file.txt
    read INPUT
    if [[ $INPUT == "Y" ]]; then
       echo $line
    fi
done < file.txt

我应该用另一种方式来读取文件吗？或者另一种读stdin的方法？

Answer 1

您可以在标准输入以外的文件描述符上打开文件.例如:

while read -u 3 line; do     # read from fd 3
  read -p "Y or N: " INPUT   # read from standard input
  if [[ $INPUT == "Y" ]]; then
    echo $line
  fi
done <3 file.txt             # open file on fd 3 for input