linux administration

File System Permissions- File System Permissions Umask :   umask is the value with this umask mask value kernel can identify who is going to create a file or directory. umask is the command to find out umask value root - umask 0022 normal -umask 0002 default permissions = maximum permissions-umask For a file :-      root      maximum permissions of a file 666                                           umask    022    (-)                                                   Normal User             maximum permissions of a file 666                                ...

User and  Group Administration - User(u)    -u Group(g) - Owner(own) Command Mode Practice These Steps:- vim  /etc/passwd : contains user information vim  /etc/shadow  : contains users password information vim  /etc/group : contains groups information cat /etc/passwd : to view total users info cat /etc/passwd | grep sam  (or) getent passwd sam : to view only sam users information cat /etc/shadow : to view passwords of all existing users cat /etc/shadow | grep sam (or) getent shadow sam : to view only sam users password cat /etc/group : to view all groups information cat /etc/group | grep hr (or) getent group hr : to view only hr group information. useradd <option> <username> -u : TO change uid syn: useradd -u <uidno> <username> ex: useradd -u 1000  sraviin -g : to add an user into a group useradd -g <groupname> <username> ex: useradd -g cyber sravn -G :to add an user in...

Linux Basic Commands-Memory related commands login to the unix/solaris server ip or host name Ex-   ip 10.1.21.1   host  usex10alg username: wesrg passwd         : ******* You will log in to the server. It will take you to default home_directory. - pwd it shows/prints the present working directory -ls -l gives listing of the files in present directory -cd .. takes you to previous directory mkdir <directory> will create directory  -mkdir -p /home/jb/j1/j2/j3 will create all the non-existing directories at a stretch -vi <file_name> opens file for reading/editing -cat <file_name> display contents of file -more <file_name> displays page by page contents of file -tail <file_name> shows last 10 lines of file use tail -f for continous update of file_name -head <file_name> shows first 10 lines of...