我正在Ubuntu系统上工作，目前我正在做的是:
if ! which command > /dev/null; then
echo -e "Command not found! Install? (y/n) \c"
read
if "$REPLY" = "y"; then
sudo apt-get install command
fi
fi
大多数人都会这么做吗?还是有更优雅的解决方案?
当前回答
既然你提到了Ubuntu，而且你想以编程的方式做到这一点(虽然也可以使用dpkg的变体，但实现起来会更复杂)，这(这)肯定是可行的:
#!/bin/bash
pkgname=mutt
which $pkgname > /dev/null;isPackage=$?
if [ $isPackage != 0 ];then
echo "$pkgname not installed"
sleep 1
read -r -p "${1:-$pkgname will be installed. Are you sure? [y/N]} " response
case "$response" in
[yY][eE][sS]|[yY])
sudo apt-get install $pkgname
;;
*)
false
;;
esac
else
echo "$pkgname is installed"
sleep 1
fi
尽管为了POSIX兼容性，您可能希望使用命令-v，正如在另一个类似问题中提到的那样。
这样的话， 在上面的代码示例中，$pkgname > /dev/null应该被命令-v $pkgname替换。
其他回答
$name="rsync"
[ `which $name` ] $$ echo "$name : installed" || sudo apt-get install -y $name
这个特性已经存在于Ubuntu和Debian的command-not-found包中。
我使用以下方法:
which mySQL 2>&1|tee 1> /dev/null
if [[ "$?" == 0 ]]; then
echo -e "\e[42m MySQL already installed. Moving on...\e[0m"
else
sudo apt-get install -y mysql-server
if [[ "$?" == 0 ]]; then
echo -e "\e[42mMy SQL installed\e[0m"
else
echo -e "\e[42Installation failed\e[0m"
fi
fi
有点以你的为基础，只是更“优雅”一点。只是因为我很无聊。
#!/bin/bash
FOUND=("\033[38;5;10m")
NOTFOUND=("\033[38;5;9m")
PKG="${@:1}"
command ${PKG} &>/dev/null
if [[ $? != 0 ]]; then
echo -e "${NOTFOUND}[!] ${PKG} not found [!]"
echo -e "${NOTFOUND}[!] Would you like to install ${PKG} now ? [!]"
read -p "[Y/N] >$ " ANSWER
if [[ ${ANSWER} == [yY] || ${ANSWER} == [yY][eE][sS] ]]; then
if grep -q "bian" /etc/os-release; then
sudo apt-get install ${PKG}
elif grep -q "arch" /etc/os-release; then
if [[ -f /bin/yay ]] || [[ -f /bin/yaourt ]]; then
yaourt -S ${PKG} 2>./err || yay -S ${PKG} 2>./err
else
sudo pacman -S ${PKG}
fi
elif grep -q "fedora" /etc/os-release; then
sudo dnf install ${PKG}
else
echo -e "${NOTFOUND}[!] This script couldn't detect your package manager [!]"
echo -e "${NOTFOUND}[!] Manually install it [!]"
fi
elif [[ ${ANSWER} == [nN] || ${ANSWER} == [nN][oO] ]]; then
echo -e "${NOTFOUND}[!] Exiting [!]"
fi
else
echo -e "${FOUND}[+] ${PKG} found [+]"
fi
对于Ubuntu来说，apt提供了一种相当不错的方式来做到这一点。下面是谷歌Chrome浏览器的一个例子:
grep -qE "(已安装|upgradeable)"|| apt-get install google-chrome-stable
我将错误输出重定向为null，因为apt警告不要使用其“不稳定的cli”。我怀疑列表包是稳定的，所以我认为可以扔掉这个警告。qq让apt变得超级安静。
