Tr
tr(1) is a character translation tool.
Contents
Installation
tr(1) will be pre-installed on any Linux or BSD operating system, as a POSIX utility.
Usage
To force text to all-lowercase, try:
echo "Hello world" | tr '[:upper:]' '[:lower:]'
Reverse the arguments to force to all-uppercase.
Tips
If you are trying to force a file to all-lowercase (or all-uppercase) and are already using vim, consider staying in the editor and using ggVGu (or ggVGU).