Editing Basic Linux Commands (section)

=== System & User Info ===
{| class="wikitable sortable"
! Command !! Description !! Usage
|-
| [[#ex-whoami|<code>whoami</code>]] || Show current user || <code>whoami</code>
|-
| [[#ex-id|<code>id</code>]] || Display user/group IDs || <code>id [USERNAME]</code>
|-
| [[#ex-df|<code>df</code>]] || Disk usage overview || <code>df [OPTIONS]</code>
|-
| [[#ex-du|<code>du</code>]] || Show disk usage for files/directories || <code>du [OPTIONS] [PATH]</code>
|-
| [[#ex-uptime|<code>uptime</code>]] || Show how long the system has been running || <code>uptime</code>
|-
| [[#ex-uname|<code>uname</code>]] || System information (kernel, OS, architecture) || <code>uname -a</code>
|-
| [[#ex-hostname|<code>hostname</code>]] || Show or set system hostname || <code>hostname</code>
|-
| [[#ex-date|<code>date</code>]] || Display or set system date/time || <code>date</code>
|-
| [[#ex-cal|<code>cal</code>]] || Display a calendar || <code>cal</code>
|-
| [[#ex-env|<code>env</code>]] || Show environment variables || <code>env</code>
|-
| [[#ex-set|<code>set</code>]] || Display shell variables and functions || <code>set</code>
|-
| [[#ex-history|<code>history</code>]] || List previously executed commands || <code>history</code>
|-
| [[#ex-ps|<code>ps</code>]] || Display running processes || <code>ps aux</code>
|-
| [[#ex-top|<code>top</code>]] || Real-time system process monitor || <code>top</code>
|-
| [[#ex-kill|<code>kill</code>]] || Terminate process by PID || <code>kill [-9] PID</code>
|-
| [[#ex-pkill|<code>pkill</code>]] || Kill processes by name || <code>pkill PROCESS_NAME</code>
|-
| [[#ex-pgrep|<code>pgrep</code>]] || Search for processes by name || <code>pgrep PROCESS_NAME</code>
|-
| [[#ex-w|<code>w</code>]] || Show who is logged in and what they are doing || <code>w</code>
|-
| [[#ex-who|<code>who</code>]] || Show who is logged in || <code>who</code>
|-
| [[#ex-last|<code>last</code>]] || Show login history || <code>last</code>
|-
| [[#ex-free|<code>free</code>]] || Show memory usage || <code>free -h</code>
|}