Ubuntu-L5-Field Marshal

A. File & Filesystem (Advanced)

1. basename – Extract filename from path

2. dirname – Extract directory from path

3. realpath – Resolve absolute path

4. readlink – Print symbolic link target

5. statfs – Filesystem statistics

6. rename – Batch rename files

7. chattr – Change file attributes

8. lsattr – List file attributes

9. statx – Extended file stats

10. syncfs – Sync filesystem

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B. Disk, Storage & Hardware

1. blkid – Block device attributes

2. findmnt – List mounted filesystems

3. mountctl – Control mounts

4. fsck – Filesystem check

5. tune2fs – Tune ext filesystems

6. resize2fs – Resize ext filesystem

7. badblocks – Check disk for bad sectors

8. hwinfo – Hardware info

9. lsusb – USB devices

10. lspci – PCI devices

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C. Networking (Advanced)

1. ip route – Routing table

2. ip neigh – ARP table

3. traceroute – Network path trace

4. mtr – Traceroute + ping

5. tcpdump – Packet capture

6. nmap – Network scanning

7. ethtool – Network interface settings

8. nmcli – NetworkManager CLI

9. whois – Domain lookup

10. arp – Address resolution table

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D. Process, Performance & CPU

1. nice – Set process priority

2. renice – Change priority

3. htop – Interactive process viewer

4. atop – Advanced system monitor

5. pidstat – Per-process stats

6. perf – Performance analysis

7. uptime – System load

8. watchdog – Monitor system health

9. schedtool – Scheduler control

10. taskset – CPU affinity

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E. Logs, Debugging & Tracing

1. journalctl -u – Logs by service

2. coredumpctl – Core dump analysis

3. strace -p – Attach syscall tracer

4. ltrace – Library call tracing

5. pmap – Process memory

6. procinfo – System info

7. dstat – Resource statistics

8. vmstat -s – Memory summary

9. free -w – Detailed memory

10. uptime -p – Pretty uptime

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F. Text Processing (Expert)

1. paste – Merge file columns

2. join – Join files

3. nl – Number lines

4. fmt – Text formatter

5. fold – Line wrapping

6. expand – Tabs to spaces

7. unexpand – Spaces to tabs

8. iconv – Encoding conversion

9. dos2unix – Line ending fix

10. unix2dos – Windows line endings

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G. Shell & Environment Mastery

1. bind – Readline bindings

2. complete – Bash autocompletion

3. compgen – Generate completions

4. shopt – Shell options

5. exec – Replace shell

6. disown – Detach jobs

7. jobs – Background jobs

8. fg – Foreground job

9. bg – Resume background job

10. wait – Wait for process

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H. Users, Groups & Security

1. useradd – Create user

2. usermod – Modify user

3. userdel – Delete user

4. groupadd – Create group

5. groups – Show group memberships

6. passwd – Change password

7. faillog – Login failure logs

8. lastlog – Last login info

9. newgrp – Switch group

10. su – Switch user

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I. Scheduling, Boot & Power

1. crontab -l – List cron jobs

2. atq – List at jobs

3. atrm – Remove at job

4. shutdown -r – Reboot schedule

5. wall – Broadcast message

6. write – Message user

7. login – Login prompt

8. logout – End session

9. halt – Stop CPU

10. reboot -f – Force reboot

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J. Packaging, Builds & System

1. dpkg -l – List packages

2. dpkg -i – Install .deb

3. apt-cache policy – Package versions

4. apt-key – Repository keys

5. add-apt-repository – Add repo

6. ldd – Shared libraries

7. ldconfig – Linker cache

8. uname -r – Kernel version

9. lsmod – Loaded kernel modules

10. modprobe – Load kernel module

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