Thanks for your rapid response. I tried to adapt your suggestion to a subroutine which I could easily drop into my test file. I found that at first it did not pass all tests. 

sub _browseruk_recognize_limited_urls {
  my ($input, $max) = @_;
  my @captures = $input =~ m[(https?://.+?)(?:,(?=http)|$)]g; 
  return [ @captures[ 0 .. $max-1 ] ];
}

[download]
Results: 
capture.t .. 
not ok 1 - 1 URL

#   Failed test '1 URL'
#   at capture.t line 18.
not ok 2 - 2 URLs (one containing a comma)
ok 3 - 3 URLs (one containing a comma)
ok 4 - Still only 3 URLs (one containing a comma); reject those over m
+ax
1..4
#     Structures begin differing at:
#          $got->[1] = undef
#     $expected->[1] = Does not exist

#   Failed test '2 URLs (one containing a comma)'
#   at capture.t line 23.
#     Structures begin differing at:
#          $got->[2] = undef
#     $expected->[2] = Does not exist
# Looks like you failed 2 tests of 4.
Dubious, test returned 2 (wstat 512, 0x200)
Failed 2/4 subtests 

Test Summary Report
-------------------
capture.t (Wstat: 512 Tests: 4 Failed: 2)
  Failed tests:  1-2
  Non-zero exit status: 2
Files=1, Tests=4,  1 wallclock secs ( 0.13 usr  0.04 sys +  0.11 cusr 
+ 0.05 csys =  0.33 CPU)
Result: FAIL

shell returned 1

[download]

However, when I grepped for definedness ... 

sub _browseruk_recognize_limited_urls {
  my ($input, $max) = @_;
  my @captures = $input =~ m[(https?://.+?)(?:,(?=http)|$)]g; 
  return [ grep { defined($_) } @captures[ 0 .. $max-1 ] ];
}

[download]
... all tests passed.

Thank you very much.

Jim Keenan

In reply to Re^2: Capturing substrings with complex delimiter, up to a maximum by jkeenan1
in thread Capturing substrings with complex delimiter, up to a maximum by jkeenan1

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