????11. ???ls?????汾
??????ls?????汾??
????# ls --version
????ls (GNU coreutils) 8.4
????Copyright (C) 2010 Free Software Foundation?? Inc.
????License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
????This is free software: you are free to change and redistribute it.
????There is NO WARRANTY?? to the extent permitted by law.
????Written by Richard M. Stallman and David MacKenzie.
????12. ??????????
?????г?ls?????????????檔
????# ls --help
????Usage: ls [OPTION]... [FILE]...
????13. ?г??????
??????ls -l?????г?/tmp???μ??????????-ld????????????/tmp?????????
????# ls -l /tmp
????total 408
????drwx------. 2 narad narad   4096 Aug  2 02:00 CRX_75DAF8CB7768
????-r--------. 1 root  root  384683 Aug  4 12:28 htop-1.0.1.tar.gz
????drwx------. 2 root  root    4096 Aug  4 11:20 keyring-6Mfjnk
????drwx------. 2 root  root    4096 Aug 16 01:33 keyring-pioZJr
????drwx------. 2 gdm   gdm     4096 Aug 21 11:26 orbit-gdm
????drwx------. 2 root  root    4096 Aug 19 08:41 pulse-gl6o4ZdxQVrX
????drwx------. 2 narad narad   4096 Aug  4 08:16 pulse-UDH76ExwUVoU
????drwx------. 2 gdm   gdm     4096 Aug 21 11:26 pulse-wJtcweUCtvhn
????-rw-------. 1 root  root     300 Aug 16 03:34 yum_save_tx-2012-08-16-03-34LJTAa1.yumtx
????# ls -ld /tmp/
????drwxrwxrwt. 13 root root 4096 Aug 21 12:48 /tmp/
????14. ????????UID??GID
??????ls -n??????????????????UID?????????userid?????ID????GID?????????groupid????ID????
????# ls -n
????total 36
????drwxr-xr-x. 2 500 500 4096 Aug  2 01:52 Downloads
????drwxr-xr-x. 2 500 500 4096 Aug  2 01:52 Music
????drwxr-xr-x. 2 500 500 4096 Aug  2 01:52 Pictures
????-rw-rw-r--. 1 500 500   12 Aug 21 13:06 tmp.txt
????drwxr-xr-x. 2 500 500 4096 Aug  2 01:52 Videos
????15. ls????????????
?????????ls???????????±???????????????ls??????????????????-l?????????????????????????б??
????# alias ls="ls -l"
??????????????????????κβ?????alias???????????????п????????alias???????????????????unalias???????
????# alias
????alias cp='cp -i'
????alias l.='ls -d .* --color=auto'
????alias ll='ls -l --color=auto'
????alias ls='ls --color=auto'
????alias mv='mv -i'
????alias rm='rm -i'
????alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
?????????????????alias??????????unalias?????ɡ?
????# unalias ls