# tr - Translate characters - run replacements based on single characters and character sets.

- Replace all occurrences of a character in a file, and print the result:

  tr find_characters replace_characters < filename

- Map each character of the first set to the corresponding character of the second set:

  tr 'abcd' 'jkmn' < filename

- Delete all occurrences of the specified set of characters from the input:

  tr -d 'input_characters'

- Compress a series of identical characters to a single character:

  tr -s 'input_characters'

- Translate the contents of the file to upper-case and print result:

  tr "[:lower:]" "[:upper:]" < filename

- Strip out non-printable characters from the file and print result:

  tr -cd "[:print:]" < filename