Great Idea,
should have come up with it myself really.

Thanks,
PerlingTheUK

update I misunderstood the question. I thought you wanted at most 6 characters, but it seems you want always exactly 6 characters. In that case use:

sprintf("%6.6s", $line)

This never works for me. In the event that len($line) > 6, sprintf will print the entire string as follows: (Win32/ActiveState 5.6.1)

use strict;
use warnings;
use diagnostics;

my $line = 'a'x 8;

my $prnline = sprintf("len(line) > 6: [%-6s]\n",$line);

$line = 'b' x 6;
$prnline .= sprintf("len(line) = 6: [%-6s]\n",$line);

$line = 'c' x 3;
$prnline .=sprintf("len(line) n 6: [%-6s]\n",$line);
 
print $prnline;

__END__
len(line) > 6: [aaaaaaaa]
len(line) = 6: [bbbbbb]
len(line) n 6: [ccc   ]
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I usually go with ikegami's option

PJ


use strict; use warnings; use diagnostics;

It's a . (maximum length) before the 6, not a - (justify left)

And it should work everywhere, otherwise you found a bug.

Ouch! how simple.

Cheers,
PerlingTheUK

Why do you not, in place of the if statement, just do: $conv = sprintf("%6f" substr($line, 0, 6));. In the case of a string longer than 6 characters, it returns only the leftmost 6 characters; in the case of a string shorter than 6 characters, it returns a string padded on the left with spaces.

Testing:

$ # String longer than 6 characters
$ perl -e '$a="1234567"; $b=sprintf("%6s", substr($a, 0, 6)); print $b
+;'
123456
$ # String shorter than 6 characters
$ perl -e '$a="123"; $b=sprintf("%6s", substr($a, 0, 6)); print $b;'
   123
$ # Example of results from OP's code
$ perl -e '$a="1234567"; $b=substr($a, 0, 6); print $b;'
123456
$ perl -e '$a="123"; $b=sprintf("%6s", substr($a, 0)); print $b;'
   123
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Hope that helps.

Because I get annoying warnings (if they are turned on) for setting the length to 6 if a string is shorter than that.

Cheers,
PerlingTheUK

print pack( 'A6', $_ ) for 'this', 'and that';

this
and th
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use strict;
use warnings;

my @lines = ( "??????????????", "123" );
my $conv;
for my $line ( @lines ){
  $conv="";
  my @c = split('', $line);
  $conv .= ($c[$_] || 0) for 0..5;
  print "$conv\n";
}
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Since these kind of questions always turn into a "let's see how many different alternatives we can come up with" contest, here's my entry:

    for (@lines) {
      $_ = sprintf "%-6s", /(.{0,6})/;
    }
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