What's the difference between nohup and ampersand (&) on Linux?

Linux provides us with different utility commands that we can make use of to print a random line from any files in the Unix command line. Mostly we make use of either the shuf command or the sort command, and in this article I’ll explain both the commands and which one is better and why.

Shuf Command

The shuf command in Linux is used to write random permutations of the input lines to the standard output. The idea of randomizing the input is the same as one does when the cards are shuffled. On most of the Linux operating systems it is present by default, as it is part of the GNU Coreutils and in case of the BSD like Mac OS X, we need to explicitly install the Coreutils first, then we can make use of it.

Syntax

shuf [OPTION] [FILE]

On Mac OS X, the syntax looks something like this −

gshuf [OPTION] [FILE]

The most basic case of making use of the shuf command is to use it without any options and file.

Example

Consider the example shown below −

immukul@192 d1 % gshuf
apple
sample
orange

Now press CTRL+D and you will get the inputs you entered in a random order printed to the screen.

Output

sample
apple
orange

Now let’s make use of the shuf/gshuf command to print a random line from a .txt file.

Consider the example shown below

Example

gshuf -n 1 file.txt

Output

unsalutary

If I run the same command again, we will get a different output.

Output

typhlopexia

Sort Command

The sort command in Linux is used to sort the contents of a file and we can use the head command along with the sort command to get a random line from a .txt file.

Consider the example shown below −

Example

sort --random-sort file.txt | head -n 1

Output

podiatry

It should be noted that it is better to make use of the gshuf command as the sort command usually takes more time.