Top 100 Linux Commands Engineers Use Daily

This page focuses on commands that are practical in real backend, DevOps, CI/CD, support and scripting work. The descriptions are short for fast lookup.

Command Reference

#	Command	Brief Description	Example
1	`pwd`	Print current directory	`pwd`
2	`ls`	List files	`ls -lah`
3	`cd`	Change directory	`cd /opt/apps`
4	`mkdir`	Create directory	`mkdir -p /opt/app/config`
5	`touch`	Create empty file	`touch app.log`
6	`cp`	Copy files	`cp app.jar /opt/apps/`
7	`mv`	Move or rename	`mv old.log archive.log`
8	`rm`	Remove files	`rm -rf temp/`
9	`rmdir`	Remove empty directory	`rmdir olddir`
10	`tree`	Show directory tree	`tree -L 2`
11	`find`	Find files	`find /opt -name '*.jar'`
12	`locate`	Fast indexed file search	`locate application.yml`
13	`which`	Locate executable	`which java`
14	`whereis`	Locate binary/source/man pages	`whereis docker`
15	`stat`	File metadata	`stat app.log`
16	`du`	Directory size	`du -sh /var/log`
17	`df`	Disk usage	`df -h`
18	`file`	Identify file type	`file app.jar`
19	`basename`	Strip path	`basename /opt/apps/app.jar`
20	`dirname`	Get directory part	`dirname /opt/apps/app.jar`
21	`cat`	Print file contents	`cat app.log`
22	`less`	View large files	`less app.log`
23	`head`	Show first lines	`head -20 app.log`
24	`tail`	Show last lines	`tail -f app.log`
25	`wc`	Count lines/words/bytes	`wc -l app.log`
26	`sort`	Sort lines	`sort users.txt`
27	`uniq`	Remove duplicates or count	`sort users.txt \| uniq -c`
28	`cut`	Extract columns	`cut -d, -f1 users.csv`
29	`paste`	Merge lines/columns	`paste a.txt b.txt`
30	`tr`	Translate/delete characters	`tr '[:lower:]' '[:upper:]'`
31	`grep`	Search text	`grep -n ERROR app.log`
32	`egrep`	Extended grep	`egrep 'ERROR\|WARN' app.log`
33	`fgrep`	Fixed string grep	`fgrep 'NullPointerException' app.log`
34	`awk`	Pattern scanning and reporting	`awk '{print $1,$4}' access.log`
35	`sed`	Stream editing	`sed 's/localhost/127.0.0.1/g' config.yml`
36	`xargs`	Build commands from input	`find . -name '*.log' \| xargs grep ERROR`
37	`tee`	Write output to file and screen	`java -jar app.jar \| tee run.log`
38	`split`	Split large files	`split -l 50000 big.log chunk_`
39	`diff`	Compare files	`diff a.txt b.txt`
40	`cmp`	Byte-level compare	`cmp file1 file2`
41	`comm`	Compare sorted files	`comm list1 list2`
42	`tar`	Archive files	`tar -czvf backup.tar.gz /opt/apps`
43	`gzip`	Compress file	`gzip app.log`
44	`gunzip`	Uncompress gz file	`gunzip app.log.gz`
45	`zip`	Create zip archive	`zip -r app.zip app/`
46	`unzip`	Extract zip archive	`unzip app.zip`
47	`ps`	List processes	`ps aux \| grep java`
48	`pgrep`	Find process by name	`pgrep -af spring`
49	`pkill`	Kill by name	`pkill -f spring`
50	`kill`	Terminate process	`kill -15 1234`
51	`killall`	Kill all matching processes	`killall java`
52	`top`	Interactive process monitor	`top`
53	`htop`	Improved process monitor	`htop`
54	`nice`	Start with priority	`nice -n 10 java -jar app.jar`
55	`renice`	Change process priority	`renice 5 -p 1234`
56	`free`	Memory usage	`free -h`
57	`uptime`	Load and uptime	`uptime`
58	`vmstat`	System performance snapshot	`vmstat 1 5`
59	`iostat`	CPU and disk IO	`iostat -xz 1 3`
60	`mpstat`	CPU per core	`mpstat -P ALL 1 3`
61	`lsof`	Open files and sockets	`lsof -i :8080`
62	`ss`	Socket statistics	`ss -tulnp`
63	`netstat`	Network stats (legacy but still common)	`netstat -tulnp`
64	`ip`	IP and route management	`ip addr`
65	`ping`	Connectivity test	`ping -c 4 google.com`
66	`traceroute`	Network path	`traceroute github.com`
67	`nslookup`	DNS query	`nslookup example.com`
68	`dig`	Advanced DNS query	`dig example.com`
69	`curl`	HTTP/API calls	`curl http://localhost:8080/actuator/health`
70	`wget`	Download file	`wget https://repo1.maven.org/...`
71	`ssh`	Remote login	`ssh user@server`
72	`scp`	Secure copy	`scp app.jar user@server:/opt/apps`
73	`rsync`	Fast sync	`rsync -avz logs/ user@server:/backup/logs`
74	`sftp`	Interactive file transfer	`sftp user@server`
75	`chmod`	Change permissions	`chmod +x deploy.sh`
76	`chown`	Change owner	`chown app:app logs/`
77	`chgrp`	Change group	`chgrp devops deploy.sh`
78	`umask`	Default permission mask	`umask 022`
79	`sudo`	Run as elevated user	`sudo systemctl restart app`
80	`su`	Switch user	`su - appuser`
81	`env`	Show environment	`env \| sort`
82	`export`	Set environment variable	`export JAVA_HOME=/opt/jdk`
83	`alias`	Create shortcut	`alias ll='ls -lah'`
84	`history`	Command history	`history \| tail -20`
85	`clear`	Clear terminal	`clear`
86	`echo`	Print text/variables	`echo $PATH`
87	`printf`	Formatted output	`printf '%s\n' hello`
88	`date`	Show date/time	`date '+%F %T'`
89	`cal`	Calendar	`cal`
90	`sleep`	Pause in scripts	`sleep 5`
91	`watch`	Repeat command	`watch -n 2 'df -h'`
92	`crontab`	Schedule recurring jobs	`crontab -e`
93	`systemctl`	Manage systemd services	`systemctl status app`
94	`journalctl`	Read service logs	`journalctl -u app -f`
95	`hostname`	Show host name	`hostname`
96	`uname`	Kernel/system info	`uname -a`
97	`whoami`	Current user	`whoami`
98	`id`	User and groups	`id`
99	`mount`	Mounted filesystems	`mount \| grep /data`
100	`umount`	Unmount filesystem	`umount /mnt/backup`
101	`docker`	Container CLI	`docker ps`
102	`git`	Version control	`git status`