Intro
Intro
Identify the host, kernel, time zone, logged-in users, environment, and high-level hardware inventory. Start here when answering “what machine is this?” and “who is on it?”.
Commands in this part
| Command | Role |
|---|---|
uname |
uname prints system information: kernel name, hostname/nodename, kernel release/version, machine hardware name, and… |
hostname |
hostname prints or sets the system hostname. |
hostnamectl |
hostnamectl queries and changes the system hostname and related machine identity fields on systemd systems. |
lsb_release |
lsb_release prints distribution identification claimed via the Linux Standard Base (LSB) interfaces and… |
uptime |
uptime shows how long the system has been running, how many users are logged in, and the load average (1, 5, and 15… |
date |
date prints or sets the system date and time. |
timedatectl |
timedatectl views and changes the system clock, timezone, RTC settings, and NTP synchronization on systemd systems. |
cal |
cal displays a calendar in the terminal — current month by default, or a specific month/year. |
whoami |
whoami prints the effective username of the current user. |
id |
id prints the real and effective user and group IDs for a process (by default, yours), plus supplementary groups. |
who |
who shows who is logged in, with terminal, login time, and sometimes host/remote info from utmp/wtmp accounting. |
w |
w shows who is logged in and what they are doing, plus system uptime and load averages. |
last |
last shows a history of logins, reboots, and runlevel changes from the wtmp accounting file (typically /var/log/wtmp). |
env |
env runs a program in a modified environment, or prints the current environment variables when given no command. |
free |
free summarizes system memory usage: physical RAM and swap. |
lscpu |
lscpu displays CPU architecture information from sysfs and /proc/cpuinfo: sockets, cores, threads, model name,… |
lsmem |
The lsmem command displays information about memory ranges and their online/offline status. |
lsusb |
lsusb lists USB devices connected to the system (buses, IDs, vendor/product strings). |
lsmod |
lsmod lists loaded kernel modules (name, size, use count, dependents). |
hwinfo |
The hwinfo command provides comprehensive hardware information. |
Suggested starting points
- Kernel/OS:
uname,lsb_release/ os-release,hostnamectl. - Time:
date,timedatectl. - Identity:
whoami,id,who,w,last. - Resources snapshot:
free,lscpu,lsmem,uptime. - Hardware peek:
lsusb,lsmod,hwinfo(deeper inventory is in Hardware).