AWK

Awk operates on a per-line basis, where it reads input line by line, applies patterns and actions, and then produces output based on those patterns.

Extracts disk usage percentage for the root file system

df -h | awk '$NF == "/" {print "Usage:", $5}'

Lists processes using more than 10% CPU

ps aux | awk '{if ($3 >= 10) print $0}'

Monitors CPU and memory usage of a process by PID

top -p PID -n 1 | awk '/PID/{getline; print "CPU:", $9, "MEM:", $10}'

Monitors CPU and memory usage of a specific user

awk -F':' '{ print "User:", $1, "Home:", $6 }' /etc/passwd

Extracts lines containing "error" from syslog

awk '/error/ {print $0}' /var/log/syslog

Displays network interfaces and their IP addresses

ifconfig | awk '/inet addr/{print "Interface:", $1, "IP:", $2}'

Checks if a service is active or not

systemctl is-active service-name | awk '{print "Service Status:", $0}'

Shows system uptime

uptime | awk '{print "Uptime:", $3, $4}'

Displays total and used memory

free -m | awk '/Mem/{print "Total Memory:", $2 "MB", "Used Memory:", $3 "MB"}'

Lists open ports in listening state

netstat -tuln | awk '/LISTEN/{print "Port:", $4}'

Lists top 5 largest directories

du -h /path | sort -rh | awk 'NR<=5{print $2, $1}'

Displays CPU model information

awk -F: '/model name/ {print "CPU Model:", $2}' /proc/cpuinfo

Monitors disk I/O for a specific disk (e.g., sda)

iostat -x 1 | awk '$1=="sda" {print "Read:", $6 "KB/s, Write:", $7 "KB/s"}'

Lists active network connections and their states

ss -tuln | awk 'NR>1 {print "Protocol:", $1, "State:", $2, "Local Address:", $4}'

Displays system load averages

uptime | awk -F'[a-z]:' '{print "Load Average (1/5/15 min):", $2, $3, $4}'

Captures CPU and memory usage snapshot

top -b -n 1 | awk '/Cpu/{print "CPU Usage:", $2 "%"}; /KiB Mem/{print "Memory Usage:", $8}'