Re: PATCH: trailing components

["Daniel Shahaf" <d.s@xxxxxxxxxxxxxxxxxx>]

Peter Stephenson wrote on Tue, 18 Jun 2019 13:01 +00:00:
> I needed to preserve a number of trailing components of a path (other
> than one) and couldn't think of an easy way of doing it.  Rather than
> craft obscure pattern substitutions, or use an ad-hoc expression to
> strip the prefix, I came up with a patch to add an optional number after
> the "t" in history style modifiers to do this.  I put it after rather
> than before because history-style colon expressions are quite sensitive
> to what the first character is after the colon.
> 
> Before I come up with tests and fix up the ensuing failures, you can let
> me know if there's a better way of doing this to save me the trouble.

Here are some alternatives, but I'm not claiming any of them is better than «${foo:t2}»:

f() {
  REPLY=
  for 1 in {1..$1} ; do REPLY=$2:t/$REPLY; 2=$2:h ; done
}
f $N "$foo"; foo=$REPLY

or

foo=${(j./.)${${(s./.)foo}[-$N,-1]}}
(plus or minus handling of runs of several consecutive slashes)

or

tmp=$foo
for i in {1..$N} ; do tmp=$tmp:h ; done
foo=${foo#$tmp/*}