rev command in Linux and how to reverse strings

What is the rev command in Linux?

What is the rev command?

As the name implies, the rev command (short for reverse) allows users to reverse a line of characters or a file.

How is the rev command used?

The rev command is typically supplied a string of characters or a file input.

rev with a file

If a file named example.txt contains:

1This is a line of text
2txet fo enil a si siht
3another one

and rev is supplied example.txt, then the output will showcase the reversed result.

1% rev example.txt
2txet fo enil a si sihT
3this is a line of text
4eno rehtona

rev with standard input

rev accepts standard input by default.

1% rev
2this is a line
3enil a si siht

OR

1% echo this is a line | rev
2enil a si siht

This is useful for scripting capabilities:

1foo="I want this text reversed"
2bar=$(echo $foo | rev)
3echo $bar