小编raf*_*ias的帖子

我有一个函数prereq()可能会被调用多次，但实际上不应通过从菜单中选择其他选项（菜单上的每个选项都作为代码的一部分）在脚本的同一运行线程上执行多次prereq()：

# Pre-requirements
prereq ()
{
        echo
        echo "########################## CHECKING PRE-REQUIREMENTS ##########################"
        echo "#                                                                             #"
        echo "Required packages: hdparm, fio, sysbench, iperf3 and sshpass"
        sleep 2
        echo
        for pack in hdparm fio sysbench iperf3 sshpass; do
                echo "Checking and if needed install '$pack'..."
                if ! rpm -qa | grep -qw "$pack"; then
                        yum install -y $pack > /dev/null
                else
                        echo "$pack is already installed, skipping..."
                        echo
                fi
        done
        echo "###############################################################################"
echo
}

该函数执行如下：

select …