[Linux] Bash who uso equivalente: Display logged-in users

Overview

The who command in Bash is used to display a list of users currently logged into the system. It provides information such as the username, terminal, login time, and originating IP address or hostname.

Usage

The basic syntax of the who command is as follows:

who [options] [arguments]

Common Options

-a: Show all available information, including users logged in and their idle time.
-b: Display the last system boot time.
-q: Show only the usernames and the number of users logged in.
-H: Print the column headers for the output.

Common Examples

Basic Usage: Display all users currently logged in.
```
who
```
Show All Information: Display detailed information about logged-in users.
```
who -a
```
Last Boot Time: Show the last time the system was booted.
```
who -b
```
Count of Logged-in Users: Display just the usernames and the count of users logged in.
```
who -q
```
With Headers: Display logged-in users with column headers.
```
who -H
```

Tips

Use who -H for a clearer output when you need to present the information.
Combine who with other commands like grep to filter results for specific users.
Regularly check who is logged in, especially on shared systems, for security purposes.