17 Essential Linux Ops Tricks to Boost Your Productivity

1. Move all *.tar files to a backup directory

find . -name "*.tar" -exec mv {} ./backup/ ;

Use find with -exec (or xargs ) to locate files and move them; other useful options include -mtime , -type , and -size .

2. Batch unzip all *.zip files to a target folder

for i in `find . -name "*.zip" -type f`; do
  unzip -d $i /data/www/img/
 done

The for … in …; do …; done loop iterates over each zip file and extracts it.

3. Common sed one‑liners (example file: test.txt)

sed -i 's/^\.//g' test.txt          # remove leading dot
sed -i 's/^/a/g' test.txt           # prepend "a" to each line
sed -i 's/$/a/' test.txt           # append "a" to each line
sed '/wuguangke/ac' test.txt       # add "c" after matching line
sed '/wuguangke/ic' test.txt       # insert "c" before matching line

Refer to sed documentation for additional patterns.

4. Check if a directory exists, create it or echo a message

if [ ! -d /data/backup/ ]; then
  mkdir -p /data/backup/
else
  echo "The Directory already exists, please exit"
fi

5. Monitor root partition usage and email when ≥90%

# Get usage percentage
usage=$(df -h | awk 'NR==2 {print $5}' | tr -d '%')
# Loop and alert
while sleep 5m; do
  if [ $usage -ge 90 ]; then
    echo "Root partition usage $usage% exceeds threshold" |
      mail -s "Warning: Disk usage $usage%" [email protected]
  fi
done

6. List top 20 IPs from Nginx access log

cat access.log | awk '{print $1}' | sort | uniq -c | sort -nr | head -20

7. Disable SELinux enforcement

sed -i '/SELINUX/s/enforcing/disabled/' /etc/selinux/config

8. Print maximum and minimum values from a file

cat a.txt | sort -nr | awk 'NR==1{print "max="$0} END{print "min="$0}'

9. Retrieve SNMP v2c data with snmpwalk

snmpwalk -v2c -c public 192.168.0.241

10. Replace lines ending with "jk" by "yz"

sed -e 's/jk$/yz/g' b.txt

11. Capture network packets with tcpdump

tcpdump -nn host 192.168.56.7 and port 80
# Exclude a host
tcpdump -nn host 192.168.56.7 or ! host 192.168.0.22 and port 80

12. Show the 20 most used commands from bash history

cat .bash_history | grep -v '^#' | awk '{print $1}' | sort | uniq -c | sort -nr | head -20

13. Delete *.log files older than 3 days

find . -mtime +3 -name "*.log" | xargs rm -rf

14. Move files larger than 100 KB to /tmp

find . -size +100k -exec mv {} /tmp \;

15. Simple firewall script allowing only remote access to port 80

iptables -F
iptables -X
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp -j REJECT

16. Nginx log statistics – top 10 IPs

cd /home/logs/nginx/default
cat access.log | awk '{print $1}' | sort -n | uniq -c | sort -nr | head -10

17. Replace directory path in a file

sed 's:/user/local:/tmp:g' test.txt