Sunday, October 24, 2010

Unix/Linux User and Group Management Commands

ac: Print statistics about users' connect time.
accton: Turn on accounting of processes. To turn it on type "accton /var/log/pacct".
adduser: Ex: adduser mark - Effect: Adds a user to the system named mark
chage: Used to change the time the user's password will expire.
chfn: Change the user full name field finger information
chgrp: Changes the group ownership of files.
chown: Change the owner of file(s ) to another user.
chpasswd: Update password file in batch.
chroot: Run command or interactive shell with special root directory.
chsh: Change the login shell.
edquota: Used to edit user or group quotas. This program uses the vi editor to edit the quota.user and quota.group files.
faillog: Examine faillog and set login failure limits.
finger: See what users are running on a system.
gpasswd: Administer the /etc/group file.
groupadd: Create a new group.
grpck: Verify the integrity of group files.
grpconv: Creates /etc/gshadow from the file /etc/group which converts to shadow passwords.
grpunconv: Uses the files /etc/passwd and /etc/shadow to create /etc/passwd, then deletes /etc/shadow which converts from shadow passwords.
groupdel: Delete a group.
groupmod: Modify a group.
groups: Print the groups a user is in
id: Print real and effective user id and group ids.
last: Display the last users logged on and how long.
lastb: Shows failed login attempts. This command requires the file /var/log/btmp to exist in order to work.
lastcomm: Display information about previous commands in reverse order. Works only if process accounting is on.
lastlog: Formats and prints the contents of the last login.
logname: Print user's login name.
newgrp: Lets a suer log in to a new group.
newusers: Update and create newusers in batch.
passwd: Set a user's pass word.
pwck: Verify integrity of password files.
pwconv: Convert to and from shadow passwords and groups.
quota: Display users' limits and current disk usage.
quotaoff or quotaon: Turns system quotas off/on.
quotacheck: Used to check a filesystem for usage, and update the quota.user file.
repquota: Lists a summary of quota information on filesystems.
sa: Generates a summary of information about users' processes that are stored in the /var/log/pacct file.
smbclient: Works similar to an ftp client enabling the user to transfer files to and from a windows based computer.
smbmount: Allows a shared directory on a windows machine to be mounted on the Linux machine.
smbpasswd: Program to change users passwords for samba.
su: Ex: su mark - Effect: changes the user to mark, If not root will need marks password.
sulogin: Single user login.
useradd: Create a new user or update default new user information.
userdel: Delete a user account and related files.
usermod: Modify a user account.
users: Print the user names of users currently logged in.
utmpdump: Used for debugging.
vigr or vipw: Edit the password or group files.
w: Display users logged in and what they are doing.
wall: Send a message to everybody's terminal.
who: Display the users logged in.
whoami: Print effective user id.

Saturday, September 4, 2010

make typescript of terminal session

Script makes a typescript of everything printed on your terminal.  It is useful for students who need a hardcopy record of an interactive session as proof of an assignment

raja@linux#script filename ( if filename is not mentioned ,typescript is taken as default name )

script session will be started which stores all the data printed on terminal in a file  ..

type exit command to stop script session ..

raja@linux # cat filename

list outs  all the commands and output ...

A good tool to use to examine the students performance .....

command based tool to teach using terminal

At the login prompt

raja@linux # ttyrec sample.tty (name can be any word)

new copy of shell will be started start typing the command ,the ttyrec will record all the keystores and outputs of command and stores as a video file ...

type exit command to stop recording ..

The play back is possible with ...

raja@linux # ttyplay sample.tty

for the above ttyrec package has to be installed ...