我想暂停shell脚本中的输入,并提示用户进行选择。标准的是、否或取消类型问题。如何在典型的bash提示符中完成此操作?


当前回答

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
}

其他回答

我建议你使用对话框。。。

Linux学徒:使用对话框改进Bash Shell脚本对话框命令允许在shell脚本中使用窗口框,以使其使用更具交互性。

它简单易用,还有一个名为gdialog的gnome版本,它采用了完全相同的参数,但在X上显示了GUI风格。

我注意到,对于这样简单的用户输入,没有人发布显示多行回声菜单的答案,所以我的做法如下:

#!/bin/bash

function ask_user() {    

echo -e "
#~~~~~~~~~~~~#
| 1.) Yes    |
| 2.) No     |
| 3.) Quit   |
#~~~~~~~~~~~~#\n"

read -e -p "Select 1: " choice

if [ "$choice" == "1" ]; then

    do_something

elif [ "$choice" == "2" ]; then

    do_something_else

elif [ "$choice" == "3" ]; then

    clear && exit 0

else

    echo "Please select 1, 2, or 3." && sleep 3
    clear && ask_user

fi
}

ask_user

发布这种方法是希望有人发现它有用且省时。

在我的情况下,我需要从下载的脚本中读取。,

curl -Ss https://example.com/installer.sh | sh

在这种情况下,read-ryn</dev/tty行允许它读取输入。

printf "These files will be uploaded. Is this ok? (y/N) "
read -r yn </dev/tty

if [ "$yn" = "y" ]; then
   
   # Yes
else
   
   # No
fi

多选版本:

ask () {                        # $1=question $2=options
    # set REPLY
    # options: x=..|y=..
    while $(true); do
        printf '%s [%s] ' "$1" "$2"
        stty cbreak
        REPLY=$(dd if=/dev/tty bs=1 count=1 2> /dev/null)
        stty -cbreak
        test "$REPLY" != "$(printf '\n')" && printf '\n'
        (
            IFS='|'
            for o in $2; do
                if [ "$REPLY" = "${o%%=*}" ]; then
                    printf '\n'
                    break
                fi
            done
        ) | grep ^ > /dev/null && return
    done
}

例子:

$ ask 'continue?' 'y=yes|n=no|m=maybe'
continue? [y=yes|n=no|m=maybe] g
continue? [y=yes|n=no|m=maybe] k
continue? [y=yes|n=no|m=maybe] y
$

它会将REPLY设置为y(在脚本中)。

read -e -p "Enter your choice: " choice

-e选项允许用户使用箭头键编辑输入。

如果要使用建议作为输入:

read -e -i "yes" -p "Enter your choice: " choice

-i选项打印提示性输入。