You seem to understand this already, but I thought I'd try to make it clear for future readers of this thread: Why doesn't it work?

When you finish slashing away at the $search string, what have you got? 

Win8 Strawberry 5.8.9.5 (32)  Sat 05/01/2021 17:03:44
C:\@Work\Perl\monks
>perl -Mstrict -Mwarnings -l

my $search = "x2\\.+\\x4";
print $search;

^Z
x2\.+\x4
  ^^
  ||
  ++----- backslash escaped literal period (one or more)

[download]
Unescaped, the . (dot) is a regex matching operator (see perlre, perlretut). Escaped, it matches a literal period, and there is no period to match in your example $text string. The + quantifier matches one or more of the atom before it, a literal period in this case.

Similar result if you pass the $search string through the qr// regex object constructor. 

Win8 Strawberry 5.8.9.5 (32)  Sat 05/01/2021 17:14:10
C:\@Work\Perl\monks
>perl -Mstrict -Mwarnings -l

my $search = "x2\\.+\\x4";
my $rx_search = qr/$search/;
print $rx_search;

^Z
(?-xism:x2\.+\x4)

[download]

Update: Minor re-formatting for clarity/coherence.

Give a man a fish:  <%-{-{-{-<

In reply to Re: Regex Search String in a Variable by AnomalousMonk
in thread Regex Search String in a Variable by roho

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