formatting strings

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks, I want to format a string so that it neatly prints 60 characters per line. The only way I know how to do this is with:

$string =~ s/(.{60})/$1\n/g;
[download]

However, i want to do this in a loop where $1 is already being used as something else, hence this doesn't work! Can anyone suggest an alternative?? Thanks!

 if ($line =~ /^\s{0,3}(\w+)(\d+)(\w+)\s+((\w+))/)  {
  # $1-$3 used by something else here
   my $string = $4;
   $string =~ s/(.{60})/$1\n/g;
   print "$string\n";
}
[download]

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Re: formatting strings by borisz (Canon) on Jan 05, 2005 at 11:10 UTC
You can use Text::Wrap, Text::Format, Text::Autoformat or whatever from CPAN. Or use your peace of code and assign the $1, $2,... to something else. `if ($line =~ /^\s{0,3}(\w+)(\d+)(\w+)\s+((\w+))/) { my ( $ws1, $num, $ws2, $string ) = ( $1, $2, $3, $5 ); $string =~ s/(.{60})/$1\n/g; print "$string\n"; }` [download] Boris	[reply] [d/l]
Re: formatting strings by ysth (Canon) on Jan 05, 2005 at 11:01 UTC
`if ($line =~ /^\s{0,3}(\w+)(\d+)(\w+)\s+((\w+))/) { # $1-$3 used by something else here my $string = $4; { $string =~ s/(.{60})/$1\n/g; } print "$string\n"; }` [download] Putting a block around it isolates the change to $1 to within that block. After the block ends, $1 will regain its previous value. But you might be better off saving the captured items to variables right away: `if (my ($word1, $number, $word2, $string) = $line =~ /^\s{0,3}(\w+)(\d+)(\w+)\s+((\w+))/) { # $word1, $number, and $word2 used by something here $string =~ s/(.{60})/$1\n/g; print "$string\n"; }` [download]	[reply] [d/l] [select]
Re: formatting strings by pelagic (Priest) on Jan 05, 2005 at 11:05 UTC
Have a look at printf to just format the printing and not the string. pelagic	[reply]
Re^2: formatting strings by legato (Monk) on Jan 05, 2005 at 14:50 UTC
Or sprintf if you really want to format just the string for some reason. Anima Legato `.oO all things connect through the motion of the mind`	[reply]
Re: formatting strings by thor (Priest) on Jan 05, 2005 at 11:54 UTC
No claims on efficiency, but `print join("\n", unpack("(A60)*", $string)"` [download] should do the trick. This also assumes a semi-recent perl (I think this feature came about sometime in 5.8). thor `Feel the white light, the light within Be your own disciple, fan the sparks of will For all of us waiting, your kingdom will come`	[reply] [d/l]
Re: formatting strings by ikegami (Patriarch) on Jan 05, 2005 at 17:31 UTC
I wrote a snippet for someone a while back. It wraps without truncating words. While it doesn't help you preserve $1 (which you could do by copying $1 into a different variable), I thought you might find it useful. `sub line_wrap { my ($str, $max) = @_; my @lines; foreach my $line (split($\, $str)) { # # Collapse spaces and tabs. # s/\s+/ /g; while (length($line) > $max) { my $max2 = $max - 1; if ($line =~ s/^(.{0,$max2}\S)\s+//s) { # Break at space. push(@lines, $1); } else { # No space. $line =~ s/^(.{$max})//s; push(@lines, $1); } } push(@lines, $line); } return join($\, @lines) . $\; }` [download] Known Bugs: Counts tabs as one char, and only does line breaks at a space.	[reply] [d/l]