> For the complete documentation index, see [llms.txt](https://thamizhiniyancs.gitbook.io/cheatsheets/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://thamizhiniyancs.gitbook.io/cheatsheets/linux/strops-text-manipulation/tr.md). # tr tr linux command cheatsheet by Thamizhiniyan C S ## Introduction Translate command(`tr`) can help you in number of ways, ranging from changing character cases in a string to replacing characters in a string. *** ## Syntax `tr [flags] [source]/[find]/[select] [destination]/[replace]/[change]` *** ## Important Flags

Flags	Description
`-d`	To delete a given set of characters
`-t`	To concat source set with destination set(destination set comes first; t stands for truncate)
`-s`	To replace the source set with the destination set(s stands for squeeze)
`-c`	This is the REVERSE card in this game, for eg. If you specify -c with -d to delete a set of characters then it will delete the rest of the characters leaving the source set which we specified (c stands for complement; as in doing reverse of something)
`[:alnum:]`	all letters and digits
`[:alpha:]`	all letters
`[:blank:]`	all horizontal whitespace
`[:cntrl:]`	all control characters
`[:digit:]`	all digits
`[:graph:]`	all printable characters, not including space
`[:lower:]`	all lower case letters
`[:print:]`	all printable characters, including space
`[:punct:]`	all punctuation characters
`[:space:]`	all horizontal or vertical whitespace
`[:upper:]`	all upper case letters
`[:xdigit:]`	all hexadecimal digits
`[=CHAR=]`	all characters which are equivalent to CHAR

*** ## Examples

Commands	Description
`cat file.txt \| tr -s '[a-z]' '[A-Z]'`	Convert every alphabetic character to upper case
`cat file.txt \| tr -s '[:lower:]' '[:upper:]'`	Convert every alphabetic character to upper case
`cat creds.txt \| tr -d '[a-zA-Z: ]'`	To view creds of a user which are in digits
`tr '()' '[]'`	To replace all parentheses ( ) with box brackets [ ]
`tr -d a-z`	To delete all the lowercase characters a-z
`tr -s ' '`	To replace all sequences of multiple spaces with just one space
`tr [:space:] "\t"`	Translates all the white-space characters to tabs
`tr -d [:digit:]`	To remove all the digits from the string
`tr -cd [:digit:]`	To remove all characters except digits ( complement )
`tr -cs 'i' '0'`	Replaces all characters except `i` with `0` and then squeezes the repeated `0` characters
`tr -cs '[:alnum:]' '\n'`	To put each word in a new line
`tr -s '\n'`	To delete the blank lines simply squeeze the repetitive newline characters
`echo $PATH \| tr ':' '\n'`	To print each directory on a separate line from the PATH environment variable
`cat .leftShift3 \| tr "d-za-cD-ZA-C" "a-zA-Z"`	Decrypt the Caesar cipher in the `.leftshift3` file