绝对最简单的解决方案是这一行，没有巧妙的技巧：

read -p "press enter ..." y

它让人想起了经典的DOS点击任意键继续，除了它等待Enter键，而不仅仅是任何键。

的确，这并没有为您提供“是”“否”“取消”的三个选项，但在您接受control-C作为“否”的情况下，这很有用。在简单脚本中取消，例如：

#!/bin/sh
echo Backup this project
read -p "press enter ..." y
rsync -tavz . /media/hard_to_remember_path/backup/projects/yourproject/

因为您不需要记住难看的命令和路径，但也不需要记住运行速度过快的脚本，而不需要在您决定它不是您想要运行的脚本之前停止。

在这种情况下，我已经多次使用case语句，使用case语句是一种很好的方法。可以实现while循环，该循环模拟case块，利用布尔条件，以便更好地控制程序，并满足许多其他要求。在满足所有条件后，可以使用中断，将控制权传递回程序的主要部分。此外，为了满足其他条件，当然可以在控制结构中添加条件语句：case语句和可能的while循环。

使用案例陈述来满足您的请求的示例

#! /bin/sh 

# For potential users of BSD, or other systems who do not
# have a bash binary located in /bin the script will be directed to
# a bourne-shell, e.g. /bin/sh

# NOTE: It would seem best for handling user entry errors or
# exceptions, to put the decision required by the input 
# of the prompt in a case statement (case control structure), 

echo Would you like us to perform the option: "(Y|N)"

read inPut

case $inPut in
    # echoing a command encapsulated by 
    # backticks (``) executes the command
    "Y") echo `Do something crazy`
    ;;
    # depending on the scenario, execute the other option
    # or leave as default
    "N") echo `execute another option`
    ;;
esac

exit

仅单个按键

这里有一个更长但可重复使用的模块化方法：

返回0=yes和1=no无需按enter键-仅需一个字符可以按enter键接受默认选择可以禁用默认选项以强制选择适用于zsh和bash。

按enter键时默认为“否”

请注意，N是大写的。此处按enter键，接受默认值：

$ confirm "Show dangerous command" && echo "rm *"
Show dangerous command [y/N]?

还要注意，[y/N]？已自动追加。默认的“no”被接受，因此不会有任何回音。

重新提示，直到给出有效响应：

$ confirm "Show dangerous command" && echo "rm *"
Show dangerous command [y/N]? X
Show dangerous command [y/N]? y
rm *

按回车键时默认为“是”

请注意，Y是大写的：

$ confirm_yes "Show dangerous command" && echo "rm *"
Show dangerous command [Y/n]?
rm *

上面，我刚刚按了回车键，所以命令运行了。

输入时无默认值-需要y或n

$ get_yes_keypress "Here you cannot press enter. Do you like this [y/n]? "
Here you cannot press enter. Do you like this [y/n]? k
Here you cannot press enter. Do you like this [y/n]?
Here you cannot press enter. Do you like this [y/n]? n
$ echo $?
1

这里，返回了1或false。请注意，使用此较低级别的函数，您需要提供自己的[y/n]？促使

Code

# Read a single char from /dev/tty, prompting with "$*"
# Note: pressing enter will return a null string. Perhaps a version terminated with X and then remove it in caller?
# See https://unix.stackexchange.com/a/367880/143394 for dealing with multi-byte, etc.
function get_keypress {
  local REPLY IFS=
  >/dev/tty printf '%s' "$*"
  [[ $ZSH_VERSION ]] && read -rk1  # Use -u0 to read from STDIN
  # See https://unix.stackexchange.com/q/383197/143394 regarding '\n' -> ''
  [[ $BASH_VERSION ]] && </dev/tty read -rn1
  printf '%s' "$REPLY"
}

# Get a y/n from the user, return yes=0, no=1 enter=$2
# Prompt using $1.
# If set, return $2 on pressing enter, useful for cancel or defualting
function get_yes_keypress {
  local prompt="${1:-Are you sure [y/n]? }"
  local enter_return=$2
  local REPLY
  # [[ ! $prompt ]] && prompt="[y/n]? "
  while REPLY=$(get_keypress "$prompt"); do
    [[ $REPLY ]] && printf '\n' # $REPLY blank if user presses enter
    case "$REPLY" in
      Y|y)  return 0;;
      N|n)  return 1;;
      '')   [[ $enter_return ]] && return "$enter_return"
    esac
  done
}

# Credit: http://unix.stackexchange.com/a/14444/143394
# Prompt to confirm, defaulting to NO on <enter>
# Usage: confirm "Dangerous. Are you sure?" && rm *
function confirm {
  local prompt="${*:-Are you sure} [y/N]? "
  get_yes_keypress "$prompt" 1
}    

# Prompt to confirm, defaulting to YES on <enter>
function confirm_yes {
  local prompt="${*:-Are you sure} [Y/n]? "
  get_yes_keypress "$prompt" 0
}

此解决方案读取单个字符，并在yes响应时调用函数。

read -p "Are you sure? (y/n) " -n 1
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    do_something      
fi

这是我在脚本/函数中通常需要的：

如果按ENTER键，默认答案为“是”也接受z（如果你在QWERTZ布局上搞混了）接受其他语言（“ja”、“Oui”、…）如果您在函数内部，请处理正确的出口

while true; do
    read -p "Continue [Y/n]? " -n 1 -r -e yn
    case "${yn:-Y}" in
        [YyZzOoJj]* ) echo; break ;;
        [Nn]* ) [[ "$0" = "$BASH_SOURCE" ]] && exit 1 || return 1 ;; # handle exits from shell or function but don't exit interactive shell
        * ) echo "Please answer yes or no.";;
    esac
done
echo "and off we go!"

echo "Please enter some input: "
read input_variable
echo "You entered: $input_variable"