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

When using format, instead of having a @< defined as a 100 character field, is there a way to say @< x 100 or anyway other way instead of having to type @< 100 times ? 
format STDOUT_TOP =
@<<<<<<<<<<<
qx(hostname)



Page @<<<
$%

<snip>
.

format STDOUT =
@<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<  @<<<<<<< @<<<<<<      @<<<<<<<<<<<<
<<<<<<<<<<<  @|||||||||||||||||| @##.##

<snip>

~~
.

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Replies are listed 'Best First'.
Re: format characters
by Fletch (Bishop) on Feb 06, 2008 at 21:43 UTC

    You could always build the format dynamically and then eval it</slightly-evil> :)

    I also think Perl6::Form has support for specifying a width numerically rather than by literal picture, but I'm not recalling how to do it offhand.

    Update: Aaah, search for "Imperative field width". 

    use strict;
use Perl6::Form;

my( $name, $age ) = ( "Fred", 23 );

print join( " "x9, 0..7 ), "\n", "0123456789"x7, "012\n";
print form
  "{<{50}<}|{|||} ",
    $name,     $age;

exit 0;

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    The cake is a lie.
    The cake is a lie.
    The cake is a lie.

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[d/l]

      OK, you already said it was evil, but eval'ing formats is accident-prone, as you will have to escape all the '@' signs. I'm with shmem here: use the editor functionality.


      Enjoy, Have FUN! H.Merijn
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Re: format characters
by shmem (Chancellor) on Feb 06, 2008 at 23:51 UTC
    You can build your format template using formline and the accumulator $^A (see perlform and perlvar). But if it's just a typing laziness issue, get a decent editor. E.g. with vi, the sequence 
    o@<^[x50p

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    (^[ being the escape key) will result in a @ followed by fifty < chars: 

    @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

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    --shmem 

    _($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}
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      I am trying what you suggested (and thank you!) but its not working. I want to replace this code: 
      <snipped the _TOP>

format STDOUT =
@<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<  @<<<<<<< @<<<<<<<      @<<<<<<<<<<<<<
<<<<<<<<<<  @||||||||||||||||||| @##.##
$sfile,                                                               
+                                $user,   $grp,        $gcos,
           dateme($mod,$mod2), $sz
~~
.

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      with this code 

      my $format  = "format STDOUT = \n"
         . '@' . '<' x 125 . $sfile             . q{  }
         . '@' . '<' x 8   . $user              . q{  }
         . '@' . '<' x 8   . $grp               . q{  }
         . '@' . '<' x 25  . $gcos              . q{  }
         . '@' . '|' x 20  . dateme($mod,$mod2) . q{  }
         . '@' . '#' x 2 . '.##' . $sz . "\n"
         . "~~\n"
         . ".\n" ;

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      And the errors I am getting are: 

      Use of uninitialized value in concatenation (.) or string at find_hog.
+tdy line 49.
Use of uninitialized value in concatenation (.) or string at find_hog.
+tdy line 49.
Use of uninitialized value in concatenation (.) or string at find_hog.
+tdy line 49.
Use of uninitialized value in concatenation (.) or string at find_hog.
+tdy line 49.
Use of uninitialized value in localtime at find_hog.tdy line 105.
Use of uninitialized value in concatenation (.) or string at find_hog.
+tdy line 49.

format STDOUT =
@<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<  @<<<<<<<<  
+@<<<<<<<<  @<<<<<<<<<<<<<<<<<<<<<<<<<  @||||||||||||||||||||19:00:00-
+12/31/69  @##.##
~~
.
Undefined format "STDOUT" called at find_hog.tdy line 227.

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      Do I use a regular write? I am confused on how write knows about $format?

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        I am trying what you suggested (and thank you!) but its not working.

        Huh? I didn't suggest that - I wrote about an editor (vi) command. But since you are bringing that up - re-read perlform, the chapter "Accessing Formatting Internals".

        If you construct your format into a string, you have to either eval it - 

        my $format = '| @' . '>' x 10 . ' | ' . '@' . '<' x 10 . " |\n"
           . '$given, $surname' ."\n"
           . '.';

eval "format STDOUT = \n$format";

for ([qw(Bill Bruford)],[qw(Ginger Baker)]) {
    ($given, $surname) = @$_;
    write;
}
__END__
|        Bill | Bruford     |
|      Ginger | Baker       |

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        or use formline and the accumulator $^A : 

        my $format = '| @' . '>' x 10 . ' | ' . '@' . '<' x 10 . " |\n";

for ([qw(Bill Bruford)],[qw(Ginger Baker)]) {
    formline( $format,@$_);
    print $^A;
    $^A = '';
}
__END__
|        Bill | Bruford     |
|      Ginger | Baker       |

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        --shmem 

        _($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}
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Re: format characters
by apl (Monsignor) on Feb 06, 2008 at 21:32 UTC
    To the best of my knowledge, you are out of luck. (That is, I have to hit '<' or '>' just as often as you do. Unfortunately.)

    I look forward to being corrected.

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