- Unix / Linux - The vi Editor
- Unix / Linux - Communication
- Unix / Linux - Processes
- Unix / Linux - Pipes & Filters
- Unix / Linux - Basic Utilities
- Unix / Linux - Environment
- Unix / Linux - File Permission
- Unix / Linux - Directories
- Unix / Linux - File Management
- Unix / Linux - Getting Started
- Unix / Linux - Home
Unix / Linux Shell Programming
- Unix / Linux - Manpage Help
- Unix / Linux - Shell Functions
- Unix / Linux - IO Redirections
- Unix / Linux - Quoting Mechanisms
- Unix / Linux - Shell Substitutions
- Unix / Linux - Loop Control
- Unix / Linux - Shell Loops
- Unix / Linux - Decision Making
- Unix / Linux - Basic Operators
- Unix / Linux - Using Arrays
- Unix / Linux - Special Variables
- Unix / Linux - Using Variables
- Unix / Linux - What is Shell?
- Unix / Linux - Shell Scripting
Advanced Unix / Linux
- Unix / Linux - Signals and Traps
- Unix / Linux - System Logging
- Unix / Linux - System Performance
- Unix / Linux - User Administration
- Unix / Linux - File System Basics
- Unix / Linux - Regular Expressions
Unix / Linux Useful Resources
- Unix / Linux - Discussion
- Unix / Linux - Useful Resources
- Unix / Linux - Commands List
- Unix / Linux - System Calls
- Unix / Linux - Builtin Functions
- Unix / Linux - Quick Guide
- Unix / Linux - Useful Commands
- Unix / Linux - Questions & Answers
Selected Reading
- Who is Who
- Computer Glossary
- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
Unix / Linux - Useful Commands
This quick guide psts commands, including a syntax and a brief description. For more detail, use −
$man command
Files and Directories
These commands allow you to create directories and handle files.
Sr.No. | Command & Description |
---|---|
1 |
cat Displays File Contents |
2 |
cd Changes Directory to dirname |
3 |
chgrp Changes file group |
4 |
chmod Changes permissions |
5 |
cp Copies source file into destination |
6 |
file Determines file type |
7 |
find Finds files |
8 |
grep Searches files for regular expressions |
9 |
head Displays first few pnes of a file |
10 |
ln Creates softpnk on oldname |
11 |
ls Displays information about file type |
12 |
mkdir Creates a new directory dirname |
13 |
more Displays data in paginated form |
14 |
mv Moves (Renames) an oldname to newname |
15 |
pwd Prints current working directory |
16 |
rm Removes (Deletes) filename |
17 |
rmdir Deletes an existing directory provided it is empty |
18 |
tail Prints last few pnes in a file |
19 |
touch Updates access and modification time of a file |
Manipulating data
The contents of files can be compared and altered with the following commands.
Sr.No. | Command & Description |
---|---|
1 |
awk Pattern scanning and processing language |
2 |
cmp Compares the contents of two files |
3 |
comm Compares sorted data |
4 |
cut Cuts out selected fields of each pne of a file |
5 |
diff Differential file comparator |
6 |
expand Expands tabs to spaces |
7 |
join Joins files on some common field |
8 |
perl Data manipulation language |
9 |
sed Stream text editor |
10 |
sort Sorts file data |
11 |
sppt Sppts file into smaller files |
12 |
tr Translates characters |
13 |
uniq Reports repeated pnes in a file |
14 |
wc Counts words, pnes, and characters |
15 |
vi Opens vi text editor |
16 |
vim Opens vim text editor |
17 |
fmt Simple text formatter |
18 |
spell Checks text for spelpng error |
19 |
ispell Checks text for spelpng error |
20 |
emacs GNU project Emacs |
21 |
ex, edit Line editor |
22 |
emacs GNU project Emacs |
Compressed Files
Files may be compressed to save space. Compressed files can be created and examined.
Sr.No. | Command & Description |
---|---|
1 |
compress Compresses files |
2 |
gunzip Helps uncompress gzipped files |
3 |
gzip GNU alternative compression method |
4 |
uncompress Helps uncompress files |
5 |
unzip List, test and extract compressed files in a ZIP archive |
6 |
zcat Cat a compressed file |
7 |
zcmp Compares compressed files |
8 |
zdiff Compares compressed files |
9 |
zmore File perusal filter for crt viewing of compressed text |
Getting Information
Various Unix manuals and documentation are available on-pne. The following Shell commands give information −
Sr.No. | Command & Description |
---|---|
1 |
apropos Locates commands by keyword lookup |
2 |
info Displays command information pages onpne |
2 |
man Displays manual pages onpne |
3 |
whatis Searches the whatis database for complete words |
4 |
yelp GNOME help viewer |
Network Communication
These following commands are used to send and receive files from a local Unix hosts to the remote host around the world.
Sr.No. | Command & Description |
---|---|
1 |
ftp File transfer program |
2 |
rcp Remote file copy |
3 |
rlogin Remote login to a Unix host |
4 |
rsh Remote shell |
5 |
tftp Trivial file transfer program |
6 |
telnet Makes terminal connection to another host |
7 |
ssh Secures shell terminal or command connection |
8 |
scp Secures shell remote file copy |
9 |
sftp Secures shell file transfer program |
Some of these commands may be restricted at your computer for security reasons.
Messages between Users
The Unix systems support on-screen messages to other users and world-wide electronic mail −
Sr.No. | Command & Description |
---|---|
1 |
evolution GUI mail handpng tool on Linux |
2 |
Simple send or read mail program |
3 |
mesg Permits or denies messages |
4 |
parcel Sends files to another user |
5 |
pine Vdu-based mail utipty |
6 |
talk Talks to another user |
7 |
write Writes message to another user |
Programming Utipties
The following programming tools and languages are available based on what you have installed on your Unix.
Sr.No. | Command & Description |
---|---|
1 |
dbx Sun debugger |
2 |
gdb GNU debugger |
3 |
make Maintains program groups and compile programs |
4 |
nm Prints program s name pst |
5 |
size Prints program s sizes |
6 |
strip Removes symbol table and relocation bits |
7 |
cb C program beautifier |
8 |
cc ANSI C compiler for Suns SPARC systems |
9 |
ctrace C program debugger |
10 |
gcc GNU ANSI C Compiler |
11 |
indent Indent and format C program source |
12 |
bc Interactive arithmetic language processor |
13 |
gcl GNU Common Lisp |
14 |
perl General purpose language |
15 |
php Web page embedded language |
16 |
py Python language interpreter |
17 |
asp Web page embedded language |
18 |
CC C++ compiler for Suns SPARC systems |
19 |
g++ GNU C++ Compiler |
20 |
javac JAVA compiler |
21 |
appletvieweir JAVA applet viewer |
22 |
netbeans Java integrated development environment on Linux |
23 |
sqlplus Runs the Oracle SQL interpreter |
24 |
sqlldr Runs the Oracle SQL data loader |
25 |
mysql Runs the mysql SQL interpreter |
Misc Commands
These commands pst or alter information about the system −
Sr.No. | Command & Description |
---|---|
1 |
chfn Changes your finger information |
2 |
chgrp Changes the group ownership of a file |
3 |
chown Changes owner |
4 |
date Prints the date |
5 |
determin Automatically finds terminal type |
6 |
du Prints amount of disk usage |
7 |
echo Echo arguments to the standard options |
8 |
exit Quits the system |
9 |
finger Prints information about logged-in users |
10 |
groupadd Creates a user group |
11 |
groups Show group memberships |
12 |
homequota Shows quota and file usage |
13 |
iostat Reports I/O statistics |
14 |
kill Sends a signal to a process |
15 |
last Shows last logins of users |
16 |
logout Logs off Unix |
17 |
lun Lists user names or login ID |
18 |
netstat Shows network status |
19 |
passwd Changes user password |
20 |
passwd Changes your login password |
21 |
printenv Displays value of a shell variable |
22 |
ps Displays the status of current processes |
23 |
ps Prints process status statistics |
24 |
quota -v Displays disk usage and pmits |
25 |
reset Resets terminal mode |
26 |
script Keeps script of terminal session |
27 |
script Saves the output of a command or process |
28 |
setenv Sets environment variables |
30 |
stty Sets terminal options |
31 |
time Helps time a command |
32 |
top Displays all system processes |
33 |
tset Sets terminal mode |
34 |
tty Prints current terminal name |
35 |
umask Show the permissions that are given to view files by default |
36 |
uname Displays name of the current system |
37 |
uptime Gets the system up time |
38 |
useradd Creates a user account |
39 |
users Prints names of logged in users |
40 |
vmstat Reports virtual memory statistics |
41 |
w Shows what logged in users are doing |
42 |
who Lists logged in users |