ls -lahtouch file.txtcp -r source/ dest/mv old.txt new.txtrm -rf dir/cat file.txthead -n 20 file.txttail -f /var/log/syslogless file.txtwc -l file.txtfile myfilestat file.txtln -s /path/to/target link_namedu -sh /var/logfind / -type f -size +100Mmkdir -p dir/subdirrmdir -p dir/subdircd -pwdtree -L 2 -I node_modulesfind /var -type d -name "*.log"grep -rn "error" /var/log/grep -E "error|warning" log.txtgrep -v "^#" config.confgrep -i "error" log.txtawk '{print $1, $3}' file.txtawk '$3 > 100' data.txtsed 's/old/new/g' file.txtsed -i 's/foo/bar/g' file.txtsed -i '/^#/d' config.confcut -d':' -f1,3 /etc/passwdsort -t',' -k2 -n data.csvsort file.txt | uniq -cecho "Hello" | tr 'a-z' 'A-Z'find . -name "*.tmp" | xargs rmmount | column -tfind /var/log -name "*.log" -mtime -7find . -name "*.bak" -exec rm {} \;which python3whereis nginxlocate filenametype lschmod 755 script.shchmod +x script.shchmod -R 755 /var/wwwchown user:group file.txtchown -R www-data:www-data /var/wwwsudo commandpasswd usernamevisudouseradd -m -s /bin/bash newuserusermod -aG docker usernameuserdel -r usernamegroupadd groupnameid usernamewhoamilast -10ps aux | grep nginxps -ef | grep nodetop -bn1 | head -20htopkill -9 PIDkillall nginxpkill -f "python app.py"nohup ./script.sh &jobs -lfg %1bg %1lsof -i :80nice -n 10 ./heavy-task.shpgrep -a nginxip addr showss -tlnpnetstat -tlnpcurl -s https://api.example.com | jqwget -q -O file.zip https://example.com/file.zipping -c 4 google.comtraceroute google.comdig example.com +shortnslookup example.comssh -p 2222 user@hostscp -r user@host:/path .rsync -avz --progress src/ user@host:/dest/ip route showiptables -L -ntcpdump -i eth0 port 80 -c 100df -hdu -sh *mount /dev/sdb1 /mnt/dataumount /mnt/datafdisk -llsblk -ffree -huname -ahostnamectl set-hostname newnameuptimedmesg | tail -50journalctl -u nginx --since todaysystemctl status nginxsystemctl start nginxsystemctl enable nginxhistory | grep "docker"alias ll='ls -lah'env | grep PATHexport MY_VAR="hello"date "+%Y-%m-%d %H:%M:%S"watch -n 2 df -htar -czf archive.tar.gz dir/tar -xzf archive.tar.gztar -cjf archive.tar.bz2 dir/tar -xjf archive.tar.bz2zip -r archive.zip dir/unzip archive.zip -d target/gzip -k file.txtgunzip file.txt.gzcrontab -ecrontab -l0 2 * * * /path/to/script.sh0 * * * * /path/to/script.sh0 0 * * 0 /path/to/weekly.shecho "command" | at now + 30 minutes