Basic Unix Commands
A quick guide to learn Unix basic commands that are used while working with Unix system with syntax.
Basic Unix commands covered in this topic are:
The Unix operating system is case sensitive. All commands must be typed in lower-case letters unless noted otherwise.
cal command in Unix
-
- calendar command is used to see the calendar of a specific month or a whole year.
Syntax:
cal [options] [arguments]
Example: cal [ [ month ] year]
|
Command |
Use |
cal
|
Shows current month calendar on the terminal |
cal DD YYYY
|
Shows calendar of selected month and year. |
cal YYYY
|
Shows the whole calendar of the year. |
cal -1
|
Shows current month calendar |
cal -s
|
Displays Sunday as the first day of the week |
cal -m
|
Displays Monday as the first day of the week |
cal -3
|
Shows calendar of previous, current and next month |
who command in Unix
-
- Displays the information about currently logged in users on the system.
Syntax
who [options]
The output is displayed in format: < Logged in Time>
|
Command |
Use |
who
|
displays the following information for each user currently logged in to the system |
who -m -H
|
displays host name and user associated with standard input |
who -a
|
display all details of current logged in user |
who -b
|
displays the time of the last system boot |
who -q
|
displays all login names and number of users logged on |
date command in Unix
-
- Displays system date and time
Syntax:
date [OPTION] [+FORMAT]
date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
-
- date (no option) : With no options, the date command displays the current date and time, including the abbreviated day name, abbreviated month name, day of the month, the time separated by colons, the time zone name, and the year.
- -u option displays time in GMT
- -d option can be used to display the date in a custom formatted way.
- date (no option) : With no options, the date command displays the current date and time, including the abbreviated day name, abbreviated month name, day of the month, the time separated by colons, the time zone name, and the year.
Use the below option:
date + “%a %d %b %Y”
%a – Abbreviated week day name(Example: Mon)
%d – Day of the Month(Eg. : 12)
%b – Abbreviated month name(Eg. : Mar)
%Y- year
Similarly various options can be used with date command to get custom date output.
clear command in Unix
-
- Clears the screen.
Syntax:
clear
more command in Unix
-
- Allows page-wise display
Syntax:
more [files]
whoami command in Unix
-
- Displays username
Syntax:
whoami
uname command in Unix
-
-
- Displays system information (kernel name, version, operating system, processor, machine hardware name, etc)
-
Syntax:
uname
-
-
- -a option displays all information
-
man command in Unix
-
-
- This displays online documentation , display the user manual of any command that we can run on the terminal
-
Syntax:
man [command]
echo command in Unix
-
-
- Echo’s to the screen whatever you type after echo.
- It is useful for producing diagnostics in command files, for sending known data into pipe, and for displaying contents of environment variables
-
Syntax:
echo[Option]
| Command | Use |
echo -e |
Enables interpretation of backslash escapes |
echo -E |
Disable the interpretation of backslash escapes. |
echo -n |
Do not output the trailing newline. |
Unix Shortcuts and other basic unix commands:
Below are the set of some commonly used shortcuts and commands that are required while working with Unix servers.
Also refer
