Can't get mv to work properly

UNIX for Beginners Q & A
1

Trying to use mv in a shell script but for some reason this does not work:

for f in *.wav;do mv $f $f.bwf;done

I get this:

usage: mv [-f | -i | -n] [-v] source target
       mv [-f | -i | -n] [-v] source ... directory

So it's like I'm using 'mv' wrong but I can't see how.

This works so the contens of the folder is read properly in the for-loop:

for f in *.wav;do echo $f;done

---------- Post updated at 01:56 AM ---------- Previous update was at 01:43 AM ----------

There are blank spaces in the filenames, do I need to take that into account?

2

Yes! Try:

for f in *.wav;do mv "$f" "$f.bwf";done
3

Yes, that works. Thanks!
But I realized i need to remove the ".wav" before adding the ".bwf".
Which is the most convenient method for that?

---------- Post updated at 10:33 AM ---------- Previous update was at 10:15 AM ----------

A tiny remark for others like me who've missed this.

I edited my script in the standard macOS Texteditor and the quotation character I get there is not the right one for bash. At least not with a Swedish keyboard.
The one used in Don's post works and looks like this:

"

The one I get from the Texteditor does not work and looks like this:

�

A tiny but significant difference. Almost invisible in some typefaces!

4

So, we move up to the next level in using shell variables (adding parameter expansions to the steps involved):

for f in *.wav;do mv "$f" "${f%wav}bwf";done

And, concerning your "tiny remark"; we usually recommend that you learn to use vi when editing shell scripts instead of using "pretty-printing editors" like TextEdit . The vi editor may have a steep learning curve, but you will learn all about using regular expressions (that you can use in sed and grep and find ) and editing commands that you can use not only in vi but also in sed , shell command history expansions, ed , ex , and cursor motion commands that apply in many other interactive commands, AND you'll get the single-quotes, double-quotes, and back-quotes you need without a pretty-printing editor's thinking that other characters might look prettier but then make your scripts fail miserably since shells don't recognize them as valid syntax.

5

Thanks, that works nicely.

I should have a look at vi.