Who & Where: whoami, uptime
Quick commands to see who you are, who else is logged in, and how the system is doing.
Syntax
whoami
uptime
free -hA handful of tiny commands answer "what is the state of this machine?"
Identity
whoami— the current user name.hostname— the machine's name.who— who is logged in right now.w— who is logged in and what they are doing.
Health
uptime— how long the system has been running, plus load averages.free -h— memory used and free, human-readable.date— the current date and time.
Example
whoami
# alice
uptime
# 09:42:11 up 5 days, 3:11, 2 users, load average: 0.15, 0.10, 0.09
free -h
# total used free
# Mem: 7.7Gi 2.1Gi 4.3GiWhen to use it
- A script validates it is running as root with 'if [ "$(whoami)" != "root" ]' before attempting system-level operations.
- A developer runs 'id' after switching users with 'su' to confirm the new UID, GID, and group memberships are correct.
- A security audit script logs 'whoami' and 'hostname' at the top of every run to create a clear audit trail of who ran what on which server.
More examples
Identify current user
Shows whoami for a quick username check and id for the full identity including all group memberships.
whoami
# alice
# Full identity: uid, gid, and all groups
id
# uid=1001(alice) gid=1001(alice) groups=1001(alice),27(sudo),998(docker)Check user in a script
Uses whoami inside a conditional to guard a script that requires root privileges.
#!/bin/bash
if [ "$(whoami)" != "root" ]; then
echo "Error: this script must run as root" >&2
exit 1
fi
echo "Root check passed, continuing..."Log identity at script start
Combines whoami, hostname, and date to write a standard audit header at the top of every automated script.
#!/bin/bash
echo "=== Job started ==="
echo "User: $(whoami)"
echo "Host: $(hostname)"
echo "Date: $(date -Iseconds)"
echo "========================"
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