当我在/etc/init.d中阅读脚本时，我注意到他们以这种方式使用了echo：
echo $"$prog not running"
而不是：
echo "$prog not running"
谁能告诉我有什么区别？
etc/init.d/autofs: echo $"$prog not running"
/etc/init.d/autofs: echo $"Reloading maps"
/etc/init.d/autofs: echo $"Usage: $0 {start|forcestart|stop|status|restart|force-reload|forcerestart|reload|condrestart|try-restart}"
/etc/init.d/avahi-daemon: echo $"Usage: $0 {start|stop|status|restart|condrestart}"
/etc/init.d/bluetooth: echo $"Usage: $0 {start|stop}"
/etc/init.d/cgred: echo $"Reloading rules configuration..."
/etc/init.d/cgred: echo $"Usage: $0 {start|stop|status|restart|condrestart|reload}"
/etc/init.d/cpuspeed: echo $2 > $cpu/cpufreq/$1
/etc/init.d/cpuspeed: echo $"Usage: $0 {start|stop|restart|condrestart|status}"
/etc/init.d/crond: echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
/etc/init.d/cups: echo $"Usage: $prog {start|stop|restart|restartlog|condrestart|try-restart|reload|force-reload|status}"
/etc/init.d/ebtables: echo $"Usage $0 {start|stop|restart|condrestart|save|status}"
/etc/init.d/firstboot: echo $"Usage: $0 {start|stop}"