You are confusing two concepts.

To concatenate strings is to combine two strings into one. The string concatenation operator is & in VB and . in Perl.

VB:
var1 = "abc" & var2

Perl (Concatenation):
$var1 = 'abc' . $var2

Perl (Interpolation):
$var1 = "abc$var2";

Perl (Concatenation using join):
$var1 = join('', 'abc', $var2);
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In VB, all statements must be on the same line. The _ operator allows you to break a statement into multiple lines. This has nothing to do with string concatenation. Perl doesn't require a continuation operator. Instead, one must tell Perl where the statement ends using ;.

VB:
var = func(var1, var2, var3)

Perl:
$var = func($var1, $var2, $var3);

VB:
var = func( _
   var1, _
   var2, _
   var3 _
)

Perl:
$var = func(
   $var1,
   $var2,
   $var3
);
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Together:

VB:
stmt = "SELECT *" & _
       "  FROM table" & _
       " ORDER BY field"

Perl:
$stmt = "SELECT *"
      . "  FROM table"
      . " ORDER BY field"

Perl (Since SQL servers treats newlines as whitespace):
$stmt = "
   SELECT *
     FROM table
    ORDER BY field
";
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Certainly free form code is much nicer. For instance you can use the string concatenation or newline examples given in other answers for tidying up your code in Socket Problem.

#!/usr/bin/perl -w
use strict;
use warnings;
use Time::Format 'time_format';

printf "Hello world, today is %s\n", time_format('mm dd yyyy',time);

exit;
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#!/usr/bin/perl -w
use strict;
use warnings;
use Time::Format 
 'time_format';

printf "Hello world, today is %s\n",
 time_format(
  'mm dd yyyy', time
 );

exit;
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#!/usr/bin/perl -w

use 
strict;
use 
warnings;
use
Time::Format
'time_format';

        printf 
"Hello world, today is %s\n",
time_format(
    'mm dd yyyy',
time)
;

   exit
;
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#!/usr/bin/perl -w
use strict;
use warnings;
use Time::Format 'time_format'

printf "Hello world, today is %s\n", time_format('mm dd yyyy',time);

exit;
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