The tr command is designed to change individual characters to different characters or to delete or reduce the number of characters.

Syntax: cat file(s) | tr '1st_char_group' '2nd_char_group'

The tr command cannot take a file name as an argument.

The tr command can handle ranges of characters:

Ideally there are the same number of characters in each group.

tr Options

The tr command is case sensitive and works on individual characters, not whole words. 

NOTE: