easy way to separate different fields?

[bsmile]

say I input aaa.f and I need to separate it into aaa and f, and then attach .f90 to aaa to form aaa.f90. How can that be most easily done? Thanks,

[scathefire]

I would write it in PERL, and I would use the split function, splitting at the dot. Then joining the two variables. It might look something like this.

$input = "aaa.f";
$ext= "f90"
($name, $discard) = split('.', $input);
$desired = join('.',$name,$ext);
print $desired;

Of course, you'd have to change it up to match how your input will be added.

[Irithori]

Yes, perl or any other language is a possibility, as it enables all kind of further processing.

For a one shot solution, a sed oneliner might also be suitable:

echo aaa.f | sed 's#^\(aaa\)\.f$#\1.f90#'
aaa.f90

You will need to adjust the regex to your actual usecase.

[drl]

Hi.

It looks like you are renaming old Fortran filenames to new filenames.

If you are using bash or ksh, you can use:

$ v="faaf.f"
$ echo ${v/.f/.f90}

producing

faaf.f90

I used versions:

GNU bash 3.2.39
ksh 93s+

This is all done within the shell as opposed to running external commands, but for a small amount of data, the difference is probably not significant. Examples of these kinds of internal manipulations can be seen at BashFAQ/100 - Greg's Wiki

Using this construct in a mv command should solve your problem. If indeed you are renaming files, you might be able to use rename:

$ touch faaf.f
$ ls -lgG *.f
-rw-r----- 1 0 Dec 15 04:21 faaf.f
$ rename --no-act 's/\.f$/.f90/' *.f
faaf.f renamed as faaf.f90

The "no-act" shows what would happen, and, when you are satisfied that it will do what you desire, the "no-act" should be removed to actually perform the rename. As I have done here, you can try that in a separate directory on test filenames.

See man pages for details.

Best wishes ... cheers, drl