$ echo abcDEF > sample1.txt $ cat sample1.txt abcDEF
$ tr a z < sample1.txt
zbcDEF
$ tr ac YZ < sample1.txt
YbZDEF
$ tr [a-z] [A-Z] < sample1.txt
ABCDEF
$ tr [A-Za-z] [a-zA-Z] < sample1.txt
ABCdef
$ tr -d '\r' < sample.dos > sample.unix
$ tr -d '\015' < sample.dos > sample.unix