blrk

root@bt:~/test# chown --helpUsage: chown [OPTION]... [OWNER][:[GROUP]] FILE... or: chown [OPTION]... --reference=RFILE FILE...Change the owner and/or group of each FILE to OWNER and/or GROUP.Wit

新创建的文件和目录，默认权限是不一样到，目录会多一个x权限。root@bt:~/test# umask0022root@bt:~/test# touch 1.txtroot@bt:~/test# mkdir 1root@bt:~/test# lldrwxr-xr-x 2 root root 4096 2013-06-08 10:38 1/-rw-r--r-- 1 roo

root@bt:~/test# chmod --helpUsage: chmod [OPTION]... MODE[,MODE]... FILE... or: chmod [OPTION]... OCTAL-MODE FILE... or: chmod [OPTION]... --reference=RFILE FILE...Change the mode of each FILE

root@bt:~/test# who --helpUsage: who [OPTION]... [ FILE | ARG1 ARG2 ]Print information about users who are currently logged in. -a, --all same as -b -d --login -p -r -t -T -u -b, --boot

root@bt:~/test# chgrp --helpUsage: chgrp [OPTION]... GROUP FILE... or: chgrp [OPTION]... --reference=RFILE FILE...Change the group of each FILE to GROUP.With --reference, change the group of eac

root@bt:~/test# ln --helpUsage: ln [OPTION]... [-T] TARGET LINK_NAME (1st form) or: ln [OPTION]... TARGET (2nd form) or: ln [OPTION]... TARGET... DIRECTORY (3rd form) o