这可能是一个黑客:

在Unix / Bash中，“xargs -p”是在运行任何命令之前提示确认的好方法吗?

我们可以使用xargs来完成这项工作:

echo ssh://username@www.example.com//somepath/morepath | xargs -p hg push

当然，这将被设置为一个别名，如hgpushrepo

例子:

$ echo foo | xargs -p ls -l
ls -l foo?...y
-rw-r--r--  1 mikelee    staff  0 Nov 23 10:38 foo

$ echo foo | xargs -p ls -l
ls -l foo?...n

$

以下是您需要的大致片段。 让我看看如何转发这些论点。

read -p "Are you sure you want to continue? <y/N> " prompt
if [[ $prompt == "y" || $prompt == "Y" || $prompt == "yes" || $prompt == "Yes" ]]
then
  # http://stackoverflow.com/questions/1537673/how-do-i-forward-parameters-to-other-command-in-bash-script
else
  exit 0
fi

注意这里的yes |命令名:)

为了避免显式检查'yes'的这些变体，你可以使用bash正则表达式操作符'=~'和一个正则表达式:

read -p "Are you sure you want to continue? <y/N> " prompt
if [[ $prompt =~ [yY](es)* ]]
then
(etc...)

它测试用户输入是否以“y”或“y”开头，后面是0个或多个“es”。

不需要按enter

这里有一个更长的，但可重用的模块化方法:

返回0=yes和1=no 不需要按enter键-只需一个字符 可以按enter键接受默认选择吗 可以禁用默认选择来强制选择吗 适用于zsh和bash。

按enter键时默认为“no”

注意，N是大写的。此处按下enter键，接受默认值:

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

还要注意，[y/N]?被自动追加。 默认的“no”被接受，所以什么都不回显。

重新提示，直到给出有效的响应:

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

按enter键时默认为“yes”

注意，Y是大写的:

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

上面，我只是按了回车键，命令就运行了。

输入- require y或n时无默认值

$ get_yes_keypress "Here you cannot press enter. Do you like this"
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1或false。注意[y/n]没有大写?

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
}

Try,

 #!/bin/bash
 pause ()
 {
 REPLY=Y
 while [ "$REPLY" == "Y" ] || [ "$REPLY" != "y" ]
 do
  echo -e "\t\tPress 'y' to continue\t\t\tPress 'n' to quit"
  read -n1 -s
      case "$REPLY" in
      "n")  exit                      ;;
      "N")  echo "case sensitive!!"   ;; 
      "y")  clear                     ;;
      "Y")  echo "case sensitive!!"   ;;
      * )  echo "$REPLY is Invalid Option"     ;;
 esac
 done
 }
 pause
 echo "Hi"

这些是哈米什的回答中更紧凑、更通用的形式。它们可以处理任何大小写字母的混合:

read -r -p "Are you sure? [y/N] " response
case "$response" in
    [yY][eE][sS]|[yY]) 
        do_something
        ;;
    *)
        do_something_else
        ;;
esac

或者，对于Bash >= version 3.2:

read -r -p "Are you sure? [y/N] " response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]
then
    do_something
else
    do_something_else
fi

注意:如果$response是一个空字符串，它将给出一个错误。要修复，只需添加引号:"$response"。-在包含字符串的变量中总是使用双引号(例如:更喜欢使用“$@”而不是$@)。

或者，Bash 4.x:

read -r -p "Are you sure? [y/N] " response
response=${response,,}    # tolower
if [[ "$response" =~ ^(yes|y)$ ]]
...

编辑:

作为对你的编辑的回应，以下是你如何根据我回答的第一个版本创建和使用确认命令(它将与其他两个类似):

confirm() {
    # call with a prompt string or use a default
    read -r -p "${1:-Are you sure? [y/N]} " response
    case "$response" in
        [yY][eE][sS]|[yY]) 
            true
            ;;
        *)
            false
            ;;
    esac
}

使用此函数:

confirm && hg push ssh://..

or

confirm "Would you really like to do a push?" && hg push ssh://..