Vi:

  • What are editors in Linux/UNIX OS?
  • A different list of editors available in Linux OS?
  • What is Vi editor?
  • How to create a new file with Vi editor?
  • How to save and exit the file in vi editor?
  • How to move a page forward in the file?
  • How to move a page backward in the file?
  • How to move half page forward and backward in the file?
  • How to search for the string in a file?
  • How to search for a string from the bottom of the file?
  • How to insert content using vi editor?
  • How to delete a line in vi editor?
  • How to delete multiple lines in vi editor?
  • How to copy and paste in vi editor?
  • Vi editor cheat sheet?

umask:

  • What is umask in Linux and UNIX machines?
  • What is the use of umask in Linux servers?
  • What are the original file and directory permissions in Linux machine?
  • What is umask default value?
  • How to change the umask value?
  • What are the configuration files related to umask values?

Head & tail:

  • How to list top 10 lines of a file?
  • How to list the top 4 lines of a file?
  • How to list the bottom 3 lines of a file using the tail command?
  • What is the use of tail -f command?
  • How to see continuous updates of a file?

more & less:

  • How to display the content of a using more command?
  • How to display the content of a using less command?
  • What are the differences between the cat, more & less commands?

find:

  • How to search for a file in Linux/UNIX system?
  • Command to search for a file based on its name in Linux?
  • How to search for files starting with "ab" characters?
  • find command syntax to search for a file in particular directory?
  • How to search for files based on the size limit in Linux?
  • How to list out the files which are accessed 2 days ago in a directory?
  • How to list out the files which are modified 4 days ago in Linux?
  • Search for the files which are not owned by any user in /etc/passwd?
  • How to Search for files starting with letters "ab" and display their content? or number of lines in those files?
  • In Linux, list out the files who's status is changed day ago?

cut:

  • Write a command to display the third and fourth character from each line of a file?
  • Write a command to display the characters from 0 to 20 from each line of a file?
  • Write a command to display the first 0 characters from each line of a file?
  • Write a command to display from the 0th character to the end of the line?
  • The fields in each line are delimited by colon Write a command to display third field from each line of a file?
  • Write a command to print the fields from to 4 from each line of a file?
  • Write a command to print the first 5 fields from each line?
  • Write a cut command to extract the username from 'who am i' command? 

User management:

Useradd:

  • How to create a new user in Linux machine?
  • What is the difference between primary group and secondary group of a user?
  • What is the userid value of a user? detail about reserved userid values?
  • Where does the user account information is stored on linux system?
  • In Linux server, where does the user password information is stored?
  • Can we have a username in capital letters in Linux machine?
  • Where does the default attributes of a user stored?

Usermod:

  • How to modify user credential details? Which command used to modify user account information?
  • How to change primary and secodary groups of a user?
  • How to add comment to an account?
  • How to lock a user account? and in which cases we lock it?
  • How to unlock the user account in linux?
  • How to modify a username for a user account in linux?
  • How to modify the userid for a user account?
  • How to check the expiry information of user account?
  • How to modify the expiry information of user?

Userdel:

  • How to delete a user account from Linux server?
  • Delete a user account along with its home directory?
  • What if we accidentally deleted a user account? What will happen and how do we solve those issues?
  • What are the things to keep in mind or checks to be done, before deleting a user account?
  • After deleting a user account, do we have to perform any housekeeping activities?

Group management:

groupadd:

  • What is group?
  • How to create a new group on server?
  • What is gid means for a group? what are its value range?
  • How and where we can check the group details exists or not? and why?

groupmod:

  • How to modify the group information?

groupdel:

  • How to delete a group from Linux system?
  • What are the pre-checks before deleting a group account?
  • What if we accidentally delete a group account?
  • Once a group is deleted, do we have to do any housekeeping works? I.e, cleaning up any pending files etc?

Configuration files:

  • What is /etc/motd configuration file used for?
  • What does /etc/bashrc configuration file contains?
  • What is /etc/profile configuration file for?
  • What is .bash_profile,.bash_logout, .bash_history and .bashrc is used for?

monitoring users:

  • How to check the logged in user details?
  • What is the difference between whoami & id command in Linux?
  • How do I know the server reboots information? such as, How many times & the date of server reboots etc?
  • How can I check a particular user login & logout details?
  • What does the finger command displays?
  • How do I know which all users are logged into particular server as of now?
  • How can we know, system load?
  • What if we want to understand the last system reboot details?
  • What is the difference between w, who and uptime commands?

chage:

  • How to disable password ageing for a particular user?
  • How to enable password expiry date of a particular user?
  • How to Set the Account expiry date in the format ‘YYYY-MM-DD’?
  • How to Set the password expiry warning message?
  • How to force a user to change password in the next login?

FTP section:

FTP Introduction:

  • What is FTP? In which scenarios we can use this protocol?
  • What is difference between FTP client and FTP server?

FTP connectivity:

  • What is active FTP mode of connectivity?
  • What is passive FTP mode of connectivity?
  • Describe the differences between active and passive mode of FTP communication?
  • In what scenario, we need to ftp the files from one server to another server?

FTP Configuration:

  • What are the packages to be installed in linux for FTP server?
  • What is the name of the ftp daemon, which is running in the back ground?
  • What are port numbers at which ftp communication will happen?
  • List out ftp configuration files on a linux machine?
  • What is the home directory of ftp user?
  • Step by step understanding on, how to configure the ftp server on RHEL machine?

FTP client configuration:

  • How to configure FTP client in RHEL machine?
  • What are list of commands from FTP client end for moving the files in and out of the server?
  • Windows acting as FTP client? FTP commands execution from FTP client. 
  • How to configure the FTP server for uploading and downloading the files?
  • How to provide root access to the FTP server?

NFS:

NFS introduction:

  • What is NFS?
  • Using NFS, can we share files and directories between cross OS platforms?
  • What are the different versions of NFS servers?
  • What are new features of NFS 4 over NFS 3?

Working with NFS:

  • How NFS works?
  • List out different NFS daemons and their functionality?

Configuring NFS server:

  • On a Linux machine,  how can we check if NFS server is installed or not? packages to be installed?
  • What are the NFS configuration files and daemons?
  • What is the default port number of NFS? can we change that NFS default port number?
  • How to configure NFS server? Step by Step explanation?
  • Step by Step explanation of NFS client configuration on Linux?
  • Explanation of /etc/exports? Examples...

uname

Let's assume, we have logged into a machine's terminal windows and want to check below details...

  • How to check the architecture of terminal machine or server?
  • How to check the type of operating system of the server?
  • Command to check the kernel release of the system?
  • Can we check the system host name information using "uname" command?
  • How to check the complete system information?

Cat:

  • What are the practical use cases of cat command?
  • How to create a new file with cat command?
  • Command to add new lines to existing file?
  • Can we use cat command to copy a file's content to another file?
  • How to display multiple file's output using cat command?
  • Instead of displaying the multiple files output on terminal, redirect it to a file. how we can achieve this?
  • Command to display the line numbers of a file?
  • Command to display line numbers of a file but avoid empty files?
  • Is it possible to display 2 files output mixed with terminal input content?
  • Is it possible to empty a file using cat command?
  • How can I see cat command options?
  • During which situations, we use copy command as Linux administrator?
  • How to make a copy of a file into same directory?
  • How to copy a file to another file but avoid overwriting if it's already existing?
  • How to copy a file from current directory to new directory?
  • How to copy multiple files from one directory to another directory?
  • How to force the copying operation?
  • How to copy entire directory to another directory?
  • How to make a directory as sub-directory in another target directory? For ex: dir should be sub-directory for dir2.
  • Which flag or option of cp command can be used to prompt the file overwriting?
  • How to copy the file from one location to another location without changing the file attributes?
  • What is the limitation of cat command in the form of copying the content to another file?
  • What is the use cases of mv command?
  • Can we rename a particular directory using mv command?
  • How to rename a file in a directory?
  • How to move a file from one directory to another directory?
  • How to move one directory files to another directory?
  • How to make a directory as sub-directory to another? For ex: dir should be sub-directory for dir2.
  • How to move a file to a target directory only when source file is newer than the target one?

mv command:

  • What is the use cases of mv command?
  • Can we rename a particular directory using mv command?
  • How to rename a file in a directory?
  • How to move a file from one directory to another directory?
  • How to move one directory files to another directory?
  • How to make a directory as sub-directory to another? For ex: dir should be sub-directory for dir2.
  • How to move a file to a target directory only when source file is newer than the target one?

wc:

  • What are some real time situations in which we use "wc" command?
  • How to check lines, words and characters of a file?
  • How to count the words in a file or an input content?
  • Which command we use for counting number of lines in a file?
  • How to print the byte or character count of a file?
  • What is the command to print length of longest line in a file?

rmdir & rm:

  • How to remove an empty directory?
  • How to remove an non empty directory or a directory with sub directories and files in it?
  • How to remove a file in a directory?
  • How to remove a file forcefully?
  • Why we need to force remove a file? What are different scenarios?
  • Command to remove multiple files at a time?
  • I have couple of files in a directory and few of them have same extensions. How can we remove those files with same extensions?

Su command

  • How to switch from one user to another user in Linux?
  • How to switch back to previous user account from present one? Or come out of present use session?
  • Why we need to switch from one user account to another user account?
  • How to switch to new user and landing into user’s home directory?
  • How can we change the new user SHELL form the default when logging in?
  • How can we switch to root user account in Linux environment?

ls:

  • How to list the files and directories in Linux/UNIX?
  • How to list the files and directories in the reverse order?
  • How to list the files with time stamp and in reverse timestamp in Linux?
  • How to list the files with size in human reversible format?
  • How to list the files with size in bytes?
  • Command to display the hidden files of a directory?
  • How list the files with their inode numbers in Linux?

cal:

  • How to display current date on UNIX terminal?
  • Command to display any particular day month and year?
  • How to display Julian dates on UNIX terminal?
  • Command syntax to display calender for the year 99?
  • cal command syntax to display current month and previous and next month calenders?
  • Command to display current month calender sheet with sunday as starting day of the week?

Date:

  • What is the date command is used for?
  • What are "date" command options that we use most frequently?
  • What are the different formating controls with "date" command?
  • How to print the date based on given date string? for ex: 2nd July 206.
  • Assume we have a file with date strings in it. how can we display proper date formats?
  • How can we know date of next friday?
  • We have a file on Linux machine and want to know the last modified date?
  • How to set the system time and date of Linux machine from terminal?
  • More date command examples with output format options?

touch:

  • What are some of practical(real time) use cases of touch command?
  • How to create an empty file?
  • How can we update the modified time of the file without modifying anything in it?
  • Command syntax to create multiple empty files through linux terminal window?