Using tr

[dos2unix]

Converting Text to Upper and Lower Case​

You can use the text replace command.

Convert to Upper Case​

To convert text to upper case, you can use the following command:

 echo "hello world" | tr '[:lower:]' '[:upper:]'

This command will output:

 HELLO WORLD

Convert to Lower Case​

To convert text to lower case, use this command:

 echo "HELLO WORLD" | tr '[:upper:]' '[:lower:]'

This command will output:

 hello world

Delete Characters​

To delete specific characters from the input, use the -d option:

 echo "hello world" | tr -d 'l'

This command will output:

 heo word

Squeeze Repeated Characters​

To replace sequences of repeated characters with a single character, use the -s option:

 echo "hellooo world" | tr -s 'lo '

This command will output:

 helo world

Replace Characters​

To replace specific characters with others, you can specify two sets of characters:

 echo "hello world" | tr 'h' 'H'

This command will output:

 Hello world

Complement Characters​

To replace all characters that are not in the specified set, use the -c option:

 echo "hello world" | tr -c 'a-z' 'X'

This command will output:

 helloXworld

Using Character Ranges​

You can also use character ranges to specify sets of characters:

 echo "hello world" | tr 'a-z' 'A-Z'

This command will output:

 HELLO WORLD

These are some of the basic and useful functions of the tr command in Linux.