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

一种简单的方法是使用xargs-p或gnu-parallel-interactive。

我更喜欢xargs的行为,因为它像其他交互式unix命令一样,在提示符后立即执行每个命令,而不是收集yes以在最后运行。(在完成所需任务后,可以按Ctrl-C键。)

例如。,

echo *.xml | xargs -p -n 1 -J {} mv {} backup/

其他回答

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)。

使用read命令:

echo Would you like to install? "(Y or N)"

read x

# now check if $x is "y"
if [ "$x" = "y" ]; then
    # do something here!
fi

然后你需要的所有其他东西

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
inquire ()  {
  echo  -n "$1 [y/n]? "
  read answer
  finish="-1"
  while [ "$finish" = '-1' ]
  do
    finish="1"
    if [ "$answer" = '' ];
    then
      answer=""
    else
      case $answer in
        y | Y | yes | YES ) answer="y";;
        n | N | no | NO ) answer="n";;
        *) finish="-1";
           echo -n 'Invalid response -- please reenter:';
           read answer;;
       esac
    fi
  done
}

... other stuff

inquire "Install now?"

...

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