????1??????????
????Linux????? ???????????????豸?????? ??????е????????init??
????init???????????????????????????????????????????￡????????? /etc/rc?? /etc/rc.d ( /etc/rc?.d) ???μ??????????????init??????????????

????/etc/rc??This file is responsible for starting/stopping services when the runlevel changes
???????磺
?????? /etc/rc.d/rc.local ??????????????????"xinit"??"startx"??????????????????????X??Window??
????2??????
????Q??bash??????????г?????????????????Щ?????????Щ??????
????A????2?????
??????????????bash?????shell
??????????????????/etc/profile-->/etc/profile.d/*.sh-->~/.bash_profile-->~/.bashrc-->/etc/bashrc
????#?????Щ????е?????????????????????????????????Ч??
???????????????bash??????shell
??????????????????~/.bashrc-->/etc/bashrc-->/etc/profile.d/*.sh

?????????Щ????в????????????????磺??????????echo?????????ε???????echo(?????????)??
????3?????????
?????????????bash?????и?????????????.bash_logout??
???????磺
??????/.bash_logout?м???????"tar ??cvzf c.source.tgz ??.c"?????????????????????? "tar" ?????? ??.c ?????
????4????????????г???
?????????at???????atd?????????????????????????????????
?????????crontab???????crond????????e???????????????????????????????????????
????Linux????????crond??????????????????????????? /var/spool/cron???μ???????????????????????趨??????????Щ????е????
??????????????crontab ?????????????????????Щ?????????
??????????……