Linux cp with a regexp

Question

I would like to copy some files in a directory, renaming the files but conserving extension. Is this possible with a simple cp, using regex ?

For example :

cp ^myfile\.(.*) mydir/newname.$1

So I could copy the file conserving the extension but renaming it. Is there a way to get matched elements in the cp regex to use it in the command ? If not, I'll do a perl script I think, or if you have another way...

Thanks

Solution 1

Suppose you have myfile.a, myfile.b, myfile.c:

for i in myfile.*; do echo mv "$i" "${i/myfile./newname.}"; done

This creates (upon removal of echo) newname.a, newname.b, newname.c.

Solution 2

The shell doesn't understand general regexes; you'll have to outsource to auxiliary programs for that. The classical scripty way to solve your task would be something like

for a in myfile.* ; do
  b=`echo $a | sed 's!^myfile!mydir/newname!'`
  cp $a $b
done

Or have a perl script generate a list of commands that you then source into the shell.

Comments

[Kerrek SB]

Does the new name somehow derive from the old name? Can you say the concrete situation, maybe it can be done with simple shell substitution.

[Johy]

Sure. The new name doesn't have a link with the old... A real example : cp treepict_313* dir/foobar.$1 foobar is a name given by a website user, it can be anything then. I just rename the file with the desired name before the user download it... To not let a formatted name as treepict_300.ext... Is this clearer ?

[Ray Toal]

Or maybe you want to rename a.c, a.s, a.o, a.h and a.bak to b.c, b.s, b.o, b.h and b.bak ?

[Johy]

That's it, but copying it in another directory in the same time (i mean, keeping a.c, a.s, a.o, a.h and a.bak)

[Kerrek SB]

@Ray: Substitution solves 90% of my file handling needs and is the prime reason for having a Bash in Windows! :-)