command line perl to not clobber symbol links

Question

I want to edit the original files with perl, when I have a numeric sequence of aliases.

The task is to use perl on the command line, e.g.

 perl -pe 's/apples/oranges/' 

But to edit files in place:

 perl -i.bak 

The -i option does not work with symbolic links

 ln -s fs fruitSalad 

With -i, perl will re-write a new file, replacing (clobbering) the prior symbolic link. i.e. it does not edit original.

There's a workaround (https://unix.stackexchange.com/questions/9318/is-there-a-way-to-make-perl-i-not-clobber-symlinks) which is like this:

 perl -i.bak -pe 's/apples/oranges/' $(readlink fs) 

Here's my problem. I want to edit in-place, the original files from a sequence of symbolic links.

 ln -s fs.1 fruitSalad-1 ln -s fs.2 fruitSalad-2 

With normal files, perl will work with ranges, e.g.

 perl -i.bak -pe 's/apples/oranges/' fs.{1..2} 

But that does not work with the $(readlink __) trick. It's not possible to combine the above, and I prefer to avoid xargs.

Any idea how to edit ranges of files via their symbolic links from the command line? What am I missing?

Answer 1

One method is to replace the contents of @ARGV (the filenames being acted on) with the target of the link prior to looping over the file contents should that file be a symbolic link.

$ mkdir blah && cd blah $ echo aa > orig $ ln -s orig slink $ perl -i -pe 'BEGIN{@ARGV=map{$_=readlink if -l}@ARGV}; s/aa/bb/' slink $ readlink slink orig $ cat orig bb $