Tip: A neat way to change file extension

Recently, I discovered a very neat way to change a file extension using command line. This trick makes use of Shell parameter expansion which works in bash, zsh, even in sh! Basically anywhere.

Example

Imagine you want to rename file.sh to file.zsh. Using the parameter expansion, you can type:

mv file.{sh,zsh}

which gets expanded to:

mv file.sh file.zsh

Neat, right? Here are some other example of using this feature:

# using enumeration
echo file-{a,b,c} # echo file-a file-b file-c

# using range
echo file-{1..4} # echo file-1 file-2 file-3 file-4

# removing extension
mv file{.txt,} # mv file.txt file

Cheers ✌️