tr - is used to translate and/or delete characters from stdin input and
writes to stdout
$ cat example.txt
linux os is powerful
linux os is versatile
linux os is best
To change all lowercase letters in the text to uppercase and vice versa
$ cat example.txt | tr [:lower:] [:upper:]
or
$ cat example.txt | tr [a-z] [A-Z]
To save the results written to stdout in a file
$ cat example.txt | tr [a-z] [A-Z] >output.txt
To send input to tr using the input redirection and redirect the output to
a file
$ tr [a-z] [A-Z] < linux.txt >output.txt
To delete characters and remove spaces
$ cat domain.txt
www. ilugc. in
www. chennaipy. org
www. google. com
$ cat domains.txt | tr -d ''
To remove repeated characters in a sequence
$ cat domains.txt
www. ilugc........... innnn
www. chennaipy. org
www. google. com
$ cat domains.txt | tr -s ''
To delete all the letters and only leave the UID
$ echo "My UID is $UID" | tr -cd "[:digit:]\n"
To break a single line of words (sentence) into multiple lines
$ echo "My UID is $UID"
$ echo "My UID is $UID" | tr " " "\n"
To translate multiple lines of words into a single sentence
$ cat uid.txt
My
UID
is
1000
$ tr "\n" " " < uid.txt
To translate single character, for instance, a space into a “ : ”
$ echo "ilugc.in =>linux,devops,cloud,programming" | tr " " ":"
$ echo "ilugc.in =>linux devops cloud programming" | tr " " ":"
regards,
T.Dhanasekar