What is use of who command in Linux?

What is use of who command in Linux? Description : The who command is used to get information about currently logged in user on to system.

Who vs who am I command in Linux? whoami command is used both in Unix Operating System and as well as in Windows Operating System. It is basically the concatenation of the strings “who”,”am”,”i” as whoami. It displays the username of the current user when this command is invoked. It is similar as running the id command with the options -un.

Who wc command Linux? 

wc command in Linux with Examples
  • wc – print newline count, word count and byte count for each file.
  • wc stands for word count is a command in Unix and Unix-like operating systems.
  • To print number of lines present in a file use -l or –lines option.
  • To print the numbers of bytes in a file use -c or –bytes option.

Who vs who am I command? Note on the difference between who and whoami . The who command will always display the account that you used to login (the real user info). The whoami command will show your effective user. This indicates that user “blammy” logged in on 23 Apr 2011 at 13:43 from ip “123.23.

What is use of who command in Linux? – Additional Questions

Who command options?

Examples of WHO Command in Unix
  • No Option. Who command without any input arguments, will display system’s information like user name, login time, terminal of user, and also the host name on the system.
  • Option -H.
  • Option -q.
  • Option -m.
  • Option -b.
  • Option -r.
  • Option -d.
  • To print system’s username.

Who am I command line?

WhoAmI Command
  • Hold down the Windows Key, and press “R” to bring up the Run window.
  • Type “CMD“, then press “Enter” to open a command prompt.
  • At the command prompt, type the following then press “Enter“: whoami.
  • The computer name or domain followed by the username is displayed.

What is tty in Unix with examples?

On Unix-like operating systems, the tty command displays the file name of the terminal connected to standard input.


-s, –silent, –quiet Print nothing, only return an exit status.
–help display this help and exit.
–version output version information and exit.

How do you use Uname?

The uname command is commonly used to checks OS details, OS architecture (32 bit or 64 bit), Linux Kernel version, and Kernel release.

Uname Command Options.

Option Description
-m Display the hardware platform name of the system
-p Display the processor type
-o Display the operating system name

What does id command do in Linux?

id command in Linux is used to find out user and group names and numeric ID’s (UID or group ID) of the current user or any other user in the server.

What is cat in shell script?

The cat (short for “concatenate“) command is one of the most frequently used commands in Linux/Unix-like operating systems. cat command allows us to create single or multiple files, view content of a file, concatenate files and redirect output in terminal or files.

What is grep command used for?

The grep command can search for a string in groups of files. When it finds a pattern that matches in more than one file, it prints the name of the file, followed by a colon, then the line matching the pattern.

Who command in Unix?

The standard Unix command who displays a list of users who are currently logged into the computer. The who command is related to the command w, which provides the same information but also displays additional data and statistics.

What is PS in Linux command?

Linux provides us a utility called ps for viewing information related with the processes on a system which stands as abbreviation for “Process Status”. ps command is used to list the currently running processes and their PIDs along with some other information depends on different options.

What is ps EF?

This command is used to find the PID (Process ID, Unique number of the process) of the process. Each process will have the unique number which is called as PID of the process.

What is TTY on Linux?

In essence, tty is short for teletype, but it’s more popularly known as terminal. It’s basically a device (implemented in software nowadays) that allows you to interact with the system by passing on the data (you input) to the system, and displaying the output produced by the system. ttys can be of different types.

What is TTY in ps command?

A TTY is a computer terminal. In the context of ps , it is the terminal that executed a particular command. The abbreviation stands for “TeleTYpewriter”, which were devices that allowed users to connect to early computers.

What is TTY Putty?

The TTY panel lets you configure the remote pseudo-terminal.

How do I use grep search?

To search multiple files with the grep command, insert the filenames you want to search, separated with a space character. The terminal prints the name of every file that contains the matching lines, and the actual lines that include the required string of characters. You can append as many filenames as needed.

What is PID and PPID in Linux?

If a command starts just one process, its PID and PGID are the same. PPID. A process that creates a new process is called a parent process; the new process is called a child process. The parent process ID (PPID) becomes associated with the new child process when it is created. The PPID is not used for job control.

What is UID and PID?

Unique. Android assigns each application a UID( userID) at the install time. Unlike PID (Process ID) which is transient and keeps changing all the time, UID stays constant as long as the application is not reinstalled.

What is TID PID?

So, a tid is actually the identifier of the schedulable object in the kernel (thread), while the pid is the identifier of the group of schedulable objects that share memory and fds (process).