Shell:以参数作为函数参数传递函数

Question

我正在编写一个shell程序来自动化我的Arch (强制性的顺便说一句)安装。为了使其更具交互性，我构建了以下功能：

  # READYN
  #   ARGS:
  #   - Yes/no question
  #   - Command to run if yes
  #   - Command to run if no
  #
  #   Prompts the user with a yes/no question (with precedence for yes) and
  #   run an order if the answer is yes or another if it's no.

readyn () {
  while :
  do
    local yn;

    printf "%s? [Y/n]: " "$1";
    read yn;

    if [[ "$yn" =~ ^([yY][eE][sS]|[yY])?$ ]]; then
      $2;
      break;
    elif [[ "$yn" =~ ^([nN][oO]|[nN])+$ ]]; then
      $3;
      break;
    fi
  done
}

--我成功地将作为参数传递给"echo Hello World!"并运行它。我还传递了另一个函数。例如：

yayprompt () {
  printf "yay is required to install %s.\n" "$1"
  readyn "Install yay, the AUR manager" "yayinstall" ""
}

如果是，这将调用yayinstall，如果不，则不做任何操作。

我的问题在于更复杂的函数，这些函数被作为参数传递，但它们要么不被识别，要么在它们不应该被识别时运行。问题在于以下功能：

  # MANAGEPGK
  #   ARGS:
  #   - Package name
  #   - Package variable
  #   - Yay required
  #
  #   Checks if the package is added to the pkglist to either add or remove it.
  #   If yay is required to install it, it prompts the user whether they wish
  #   to install yay or don't install the package (if yay is not installed).
  #   This functions DOES NOT prompt any installation options on the user. To
  #   do this, use PROMPTPKG.

managepkg () {
  local pkgvar=$2

  if [ $pkgvar == 0 ]; then
    if [ $3 == 1 ] && [ $yay == 0 ]; then
      yayprompt;
    fi

    if [ $3 == 0 ] || [ $yay == 1 ]; then
      addpkg "$1";
      pkgvar=1;
    fi
  else
    rmpkg "$1";
    pkgvar=0;
  fi

  echo "$pkgvar";
}

要使它正常工作，就必须(或者至少我不得不)这样称呼它：

dewm_cinnamon=$(managepkg cinnamon $dewm_cinnamon 0)

现在，我试图将它作为参数传递给readyn，但这些输出取决于格式(我总是将yes回答为空字符串：

单引号：

readyn "Install gaps" \
       'dewm_i3gaps=$(managepkg i3-gaps $dewm_i3gaps 0)' \
       'dewm_i3=$(managepkg i3-wm $dewm_i3 0)';

Install gaps? [Y/n]:
./architup.sh: line 341: dewm_i3gaps=$(managepkg: command not found

双引号：

readyn "Install gaps" \
       "dewm_i3gaps=$(managepkg i3-gaps $dewm_i3gaps 0)" \
       "dewm_i3=$(managepkg i3-wm $dewm_i3 0)";

Install gaps? [Y/n]: 
./architup.sh: line 341: dewm_i3gaps=1: command not found

随附的美元：(这个命令运行两个命令，如cat pkglist中所示)

readyn "Install gaps" \
       $(dewm_i3gaps=$(managepkg i3-gaps $dewm_i3gaps 0)) \
       $(dewm_i3=$(managepkg i3-wm $dewm_i3 0));

Install gaps? [Y/n]: 
Install compton? [Y/n]: ^C

Documents/Repositories/architup took 5s 
➜ cat pkglist
i3-gaps
i3-wm

我应该使用什么语法让readyn只运行基于用户输入的一个命令？

谢谢!

Answer 1

函数参数只是字符串。更好的设计是让readyn返回true (0)表示“是”，否则返回false，并让调用代码在此基础上实现任何条件逻辑。

readyn () {
    read -p "$@"
    case $REPLY in
        [Yy] | [Yy][Ee][Ss]) return 0;;
    esac
    return 1
} 

readyn "Are you ready San Antonio?" &&
rock and roll

if readyn "Let me hear you say yeah"; then
    echo "Let's go!"
else
     echo "If you feel mellow, get outta here"
fi

(向各地的摇滚音乐会道歉，)