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in reply to How to match last character of string, even if it happens to be a newline?

By default, the  . (dot) regex metacharacter matches everything except a newline. Use the  /s modifier to make dot match everything. 

c:\@Work\Perl\monks>perl -wMstrict -le
"use Data::Dump qw(pp);
 ;;
 for my $s (qq{yz}, qq{yz\n}) {
   $s =~ m{ (.) \z }xms;
   printf qq{in %s matched %s \n}, pp($s), pp($1);
   }
"
in "yz" matched "z"
in "yz\n" matched "\n"

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See also  \z for "absolute end of string" anchor.

Update: You're also running into an interaction with  $ which matches | which by default matches at "the end of the line (or before newline at the end)", so even with the  /s modifier, the first position at which  .$ can possibly match (scanning from left to right) is before a newline, if present; remember that the matching rule is leftmost longest.

Give a man a fish:  <%-{-{-{-<

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Re^2: How to match last character of string, even if it happens to be a newline?
by Allasso (Monk) on May 12, 2019 at 15:11 UTC
    Yes, the \z anchor does, the trick, thanks!
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Re^2: How to match last character of string, even if it happens to be a newline?
by Allasso (Monk) on May 12, 2019 at 15:17 UTC
    Using \z, I don't seem to need multiline, simply m@(.)\z@s
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      Using \z, I don't seem to need multiline ...

      That's because  \z is always the absolute end-of-string anchor; no modifiers apply. I always use  \A \z \Z because they have invariant behavior. For the same reason, I nail down the  ^ $ operators by always using the  /m modifier. (I then use the  ^ $ operators only with newlines embedded within a string.)

      Give a man a fish:  <%-{-{-{-<

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Re^2: How to match last character of string, even if it happens to be a newline?
by Allasso (Monk) on May 12, 2019 at 15:04 UTC
    er... I _did_ use s modifier :-/
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