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}'
