Linux Commands Every Developer Must Know

Linux Commands Every Developer Needs

Linux is the OS of production servers. These commands are used daily for debugging, log analysis, process management, and server configuration.

ls -la                         # list with permissions
find . -name "*.log" -mtime -1 # files modified in 24h
du -sh /var/log/*              # directory sizes
df -h                          # disk space usage

grep -r "Error" /var/log/      # search all logs
grep -i "fatal" app.log | tail -20   # case-insensitive, last 20
awk '{print $1}' access.log | sort | uniq -c | sort -rn | head  # top IPs
sed 's/ERROR/CRITICAL/g' app.log     # replace in stream

ps aux | grep nginx            # find process
top / htop                     # real-time monitor
kill -9 PID                    # force kill
lsof -i :3306                  # what's on port 3306
netstat -tulpn                 # all listening ports

tail -f /var/log/nginx/error.log             # follow live log
tail -f app.log | grep -v "DEBUG"            # filter on-the-fly
journalctl -u php8.3-fpm --since "1 hour ago"

chmod 755 script.sh            # rwxr-xr-x
chown www-data:www-data -R storage/

curl -I https://ezycoders.in                 # HTTP headers
ssh user@192.168.1.100
scp file.php user@server:/var/www/

free -h                        # memory usage
uname -a                       # kernel version
uptime                         # load average