The arguments or parameters are extra information you are passing into the command. Use spaces to separate commands from the argument.
This runs the program “python3” with the argument “hello.py”
If you leave the space out and type
…the computer will look for a command called
python3hello. You must use
spaces as separators on the command line.
To rename the file
banana.txt, use the
mv (move) command:
mv apple.txt banana.txt
The command is
mv, the first argument is
apple.txt and the second argument
If you have a file called
I am a file.txt you have a problem:
mv I am a file.txt banana.txt
…because your computer will try to rename the file called
I — and that file
probably doesn’t exist. You can fix this either using quotation marks or by
“escaping” the space:
mv "I am a file.txt" banana.txt
If you’re going to study computer science, make your life easier and never put
spaces (or other special characters) into filenames. Of course you can put
fancy things into your filenames, but you can avoid a world of pain by sticking
to numbers, lowercase letters, hyphen (
-), underscore (
_) and dot (
For similar reasons, it’s usually simpler to keep everything lower case. For
more detail, see the intro about file systems.
Sometimes you must use capital letters in filenames: if there’s a good reason (because the programming language you are using requires it) then of course, that’s what you do.