??????????????
????????????????????????????????????:r?????????w????д????x??????У?????????????????????????????????????????????????????????д????????У?
????r?? ???ж???????б?????????????ls(list)
????w?????и????????б??????????????????????????????????????????
????x????????????????????????? ???????cd
????????????cd?????????????????????????
???????????????????λ????s??t?????????????????????ο? ??Linux????????SUID??SGID??SBIT?? ???????????????
????· ???????SUID??????????????д???????????????й?????????????????????
????· ??????SGID?????????????????????????????????鶼?????????????????
????· ??????SBIT?????????????????????????????????????root??????
????atime & noatime
?????????? atime???????????????????????????￡???cat????????????????????????????з????仯??????????????????и??atime???????????????￡???????￡?
???????????????????Щ?????????????????????? Linux ????????????????????? noatime ??????????????????????????????￡?Linux ext2/ext3 ???????????????????????????????????????????Щ?????????磺?????????????????????????η??????????????е??????? ???????????????????Щ?????????????????????????????????????????? IO ??Ч???????????????????Linux ???? noatime ???????????????????η?????????
?????? wiki stat ??????ж??????????????????“Criticism_of_atime”????????atime?????????????????
????· strictatime (formerly atime?? and formerly the default; strictatime as of 2.6.30) – always update atime?? which conforms to the behavior defined by POSIX
????· relatime ("relative atime"?? introduced in 2.6.20 and the default as of 2.6.30) – only update atime under certain circumstances: if the previous atime is older than the mtime or ctime?? or the previous atime is over 24 hours in the past
????· nodiratime – never update atime of directories?? but do update atime of other files
????· noatime – never update atime of any file or directory; implies nodiratime; highest performance?? but least compatible
????· lazytime – update atime according to specific circumstances laid out below
????????noatime?????????????κ??????????atime???????????/etc/fstab??for example??

???????????????????
????????????????????????????????inode??
??????????????????????????????????????????????meta data??????????????????????????洢??????????????·???????????????????????windows?е?“?????”??
????linux?????????? ln src target ?????????????target???????src??????????????????inode????meta data?????????????????????????????????????????????????ln Server.log Server_hardlink.log

??????????????meta data?????????????????????????????仯???? Links ??????????2?????????Server_hardlink.log???????????????????????????????????????????rm??????????????????????????links???????1????е?links????????0???????????????????
????linux?????????? ln -s src target ??????????????????????????src??target??????????inode