how to rename multiple files in a folder with a specific format? perl syntax explanation

Question

This question already has answers here: question from:https://stackoverflow.com/questions/65890685/how-to-rename-multiple-files-in-a-folder-with-a-specific-format-perl-syntax-exp

Answer 1

First of all, Argument list too long doesn't come from perl; it comes from the shell because you have so many files that *.fits expanded to something too long.

To fix this, use

# GNU
find . -maxdepth 1 -name '*.fits' -exec rename ... {} +

# Non-GNU
find . -maxdepth 1 -name '*.fits' -print0 | xargs -0 rename ...

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But your Perl code is also incorrect. All you need is

s/^(d+).*/$1-HSC-I-psf.fits/

which can also be written as

s/^d+K.*/-HSC-I-psf.fits/