shell之dialog提示窗口

#!/bin/bash

temp=`mktemp -t test.XXXXXX`
temp2=`mktemp -t test2.XXXXXX`
function diskspace {
    df -k > $temp
    dialog --textbox $temp 20 60
}
function whoseon {
    who > $temp
    dialog --textbox $temp 20 50
}

function memusage {
    cat /proc/meminfo > $temp
    dialog --textbox $temp 20 50
}

while [ 1 ]
do
    dialog --menu "Sys Admin Menu" 20 30 10 1 "Display disk apace" 2 "Display users" 3 "Display memory usage" 0 "Exit" 2>$temp2
    if [ $? -eq 1 ]
    then
        break;
    fi
    selection=`cat $temp2`
    case $selection in
    1)
        diskspace ;;
    2)
        whoseon ;;
    3)
        memusage ;;
    0)
        break ;;
    *)
        dialog --msgbox "Sorry,incalid selection" 10 30
    esac
    done
    rm -f $temp $temp2 2> /dev/null