"Renaming files is one thing that a good GUI file manager
appears to have over the CLI. Usually clicking on a file name will
give you the opportunity to edit the name in order to rename it,
which is great for files with long names. This can be done easily
in a shell too, either by using tab expansion or with this little
trick:
$ mv thisisareallylongfilename{,.txt}
"This will move the file "thisisareallylongfilename" to
"thisisareallylongfilename.txt" without having to type it
twice."