Re: zmv pattern for directory and multiple file types

[Daniel Shahaf <d.s@daniel.shahaf.name>]

Ahmad Ismail wrote on Sat, 14 Nov 2020 03:45 +0600:
> Hi All,
> 
> I have the following functions that rename files from camel to sort of
> kebab case.
> 
> function ctokfiles() {
>     # Transform [Capital][Capital][Small] to [Capital]-[Capital][Small]
>     zmv -Q '(**/)(*[A-Z][A-Z][a-z]*)(.adoc|.txt)' '$1${2//(#b)([A-Z])([A-Z][a-z])/$match[1]-$match[2]}$3'
> 
>     # Put - Between [Small][Capital]
>     zmv -Q '(**/)(*[a-z][A-Z]*)(.adoc|.txt)' '$1${2//(#b)([a-z])([A-Z])/$match[1]-$match[2]}$3'
> 
>     # Change [Capital][Small] to Lovercase
>     zmv -Q '(**/)(*[A-Z][a-z]*)(.adoc|.txt)' '$1${2//(#m)[A-Z][a-z]/${(L)MATCH}}$3'
> }  
> 
> So, IF the input name is "ThisIsMyOCDTalking", it becomes
> "this-is-my-OCD-talking".
> 
> Now I want to rename directories, adoc & txt files only. For directories, I
> think I have to use
> 
>     zmv -Q '(**/)(*[A-Z][A-Z][a-z]*)(/)'
> 
> How to make a function that will work on adoc, txt and directories. I tried
> (/|.adoc|.txt), apparently not working.
> 

Consider how in «*foo*(bar)», the «foo» are matched against the
filename but the «bar» are parsed as glob qualifiers.  You can't just
juxtapose them within the same set of parentheses; they're apples and
oranges.

I don't see a good solution for "Everything in «**/*» that's
a directory or named *.foo or *.bar".  I'd consider find(1) for this.

> One more thing, is there any way I can reduce the steps in this functions.

As a rule, I wouldn't recommend reducing steps in functions in the
first place, unless you're coding for sport rather than robustness — in
which case, I'd probably opt for Perl:

% print -rNC1 -- *.(adoc|txt)(N) *(/N) | rename -0 -n '$_ = join "-", map { /[a-z]/ ? lc : $_ } split /(?<=[a-z])(?=[A-Z])|(?=[A-Z][a-z])/'
rename(ThisIsMyOCDTalking.adoc, this-is-my-OCD-talking.adoc)
% 

The main algorithmic difference is splitting the filename into an array
on zero-width lookaround matches.  I don't think there's a native zsh
equivalent of this.

Note that changing «print -rNC1» to «ls» would introduce two separate bugs.

I'm not sure how to extend this to nested hierarchies, given the
possibility of foo/bar where both foo and bar have to be changed.
Perhaps with «rename -d» and ensuring the input is sorted children
before their parents.

Cheers,

Daniel