有人可以帮助找出我的 for 循环脚本有什么问题吗?我正在尝试使用 for 循环从变量列表安装包。我的问题是,当获取第一个要安装的包时,同时从列表中获取包。它还会同时安装所有软件包。我如何检查修复它。我需要一次做一个。
REQPKGS="redhat-lsb-core telnet"
for pkg in $REQPKGS; do
if yum -q list installed "$REQPKGS" > /dev/null 2>&1; then
echo -e "$pkg is already installed"
else
yum install $REQPKGS -y
echo "Successfully installed $REQPKGS"
fi
done
我的脚本的结果:
+ REQPKGS='redhat-lsb-core telnet'
+ for pkg in '$REQPKGS'
+ yum -q list installed 'redhat-lsb-core telnet'
+ yum install redhat-lsb-core telnet -y
+ echo 'Successfully installed redhat-lsb-core telnet'
Successfully installed redhat-lsb-core telnet
+ for pkg in '$REQPKGS'
+ yum -q list installed 'redhat-lsb-core telnet'
+ yum install redhat-lsb-core telnet -y
Loaded plugins: product-id, refresh-packagekit, rhnplugin, security, subscription-manager
This system is receiving updates from RHN Classic or RHN Satellite.
Setting up Install Process
Package redhat-lsb-core-4.0-7.el6.x86_64 already installed and latest version
Package 1:telnet-0.17-48.el6.x86_64 already installed and latest version
Nothing to do
+ echo 'Successfully installed redhat-lsb-core telnet'
Successfully installed redhat-lsb-core telnet
答案1
$REQPKGS
您在循环中使用数组变量 ( ) 而不是循环变量 ( $pkg
),因此它完全按照您的指示执行操作,同时安装两个软件包两次。
将循环内部更改for
为:
REQPKGS=(redhat-lsb-core telnet)
for pkg in "${REQPKGS[@]}"; do
if yum -q list installed "$pkg" > /dev/null 2>&1; then
echo -e "$pkg is already installed"
else
yum install "$pkg" -y && echo "Successfully installed $pkg"
fi
done
使用for
循环时,您定义的变量for
保存循环每次迭代的值;在您的情况下,一次包含单个包的变量是$pkg
。
或者
REQPKGS=(redhat-lsb-core telnet)
yum install -y "${REQPKGS[@]}"
将安装指定的所有未安装的软件包,并跳过所有已安装的软件包。