I’m Nishal. I came to Hamon as a UI/UX designer. At Hamon my first project was Lycaeum. Since then I have been handling the UI/UX work for Lycaeum. As a part of Lycaeum project expansion I got this wonderful opportunity to attend the mentoring class of Noufal Sir. This was totally a new experience for me. This is a five months course. For that he gave us a monthly activity calendar.
Daily we have to practise
Gtypist in the shell, practise programming and read Technical and Non-technical books which he suggested.
Every Monday a five minutes presentation on a topic assigned to each of us.
Blogging on Sundays.
We have to tick daily activity progress. This changed me a lot. After seeing all the ticks, my confidence level has increased significantly.
Here I am going to explain about the presentation topic I was assigned to last Monday. Each of the attendees got a different command used in UNIX programming. I got the command
What is the shuf command in UNIX?
shuf command generates random permutations from input lines to standard output. If given a file or series of files it will shuffle the lines and write the result to standard output. It can also limit the number of results returned supporting selecting random lines from a file or data from a list.
How to shuffle the contents of a file
To shuffle the lines in a file using the
shuf command pass a file, files or standard input to the command. The result will be printed to standard output. In the following example we have a list of cards in a file saved as
poem.txt This file is ordered by suit and number.
cat poem.txt Water,water,every where, And all the boards did shriks; Water, water, every where, Nor any drop to drink
shuf poem.txt Nor any drop to drink Water,water,every where, And all the boards did shriks; Water, water, every where,
shuf command shuffles the lines and outputs this to standard output.
How to pick a random line from a file
To pick a random line from a file using
shuf use the
-n option. This limits the output to the number specified.
shuf -n 1 cards.txt KH
To select more than one line change the number.
shuf -n 5 cards.txt 4H 9S KH 9D 9H
How to shuffle standard input
To shuffle words passed to
shuf in standard input use the
-e option. This shuffles items separated by spaces.
shuf -e one two three three two one
If you wanted to quickly decide whose turn it is to make the tea you can use
shuf -n 1 -e Muhammed Nishal Bea Bea
Bea make the tea!