Plaintext underlining tool

Here is a small tool I use to underline plaintext. It has a little bit more logic than the vi idiom yyp:s/./-/g built into it in that it can generate underlining patterns of more than one character (like o=o=o=o) and it copys indentation and bigspace (i.e. whitespace containing tabs) as-is from the original text.

To minimize typing overhead I install it under 5 different names (using links) and let it use its name as a parameter. The names aul, bul, cul and dul give me four standard line types, while pul takes an arbitrary line pattern as its first argument.

#!/usr/bin/perl

# aul, bul, cul, dul, pul - plaintext underline helpers
# [abcd]ul use some fixed underline character,
# pul uses its first argument as pattern

use strict;
use warnings;
use integer;
use File::Basename qw(basename);

$0 = basename($0);
my $pat =
   {qw(a - b = c ~ d ^)}->{substr($0, 0, 1)} || shift;
die "usage: $0 pattern [file]...\n"
   if !defined($pat) || '' eq $pat;
my $len  = length($pat);

while (<>) {
   print;
   s/\S/x/g;                   # underline non-whitespace
   1 while s/x (?= *x)/xx/;    # and inner blanks
   if (1 == $len) {            # finally apply texture
      s/x/$pat/g;
   }
   else {
      s{(x+)}{substr(
         $pat x (length($1)/$len+1), 0, length($1)
      )}ge;
   }
   print;
}
[download]

Comment on Plaintext underlining tool Download Code

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Re: Plaintext underlining tool by chanio (Priest) on Jan 28, 2006 at 23:32 UTC
Nice! I did this example that I call 'the Pine Tree' pattern... cat <<'EOF'\| perl pul.pl '/\' > Kernel-disk plus a disk containing the initial ramdisk, which will b +e > prompted for at boottime. > > If you wish to remaster the CD, please don't forget to specify > -no-emul-boot -boot-load-size 4 -boot-info-table \ > -b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat > as option to mkisofs. Otherwise your CD won't be bootable. > EOF Kernel-disk plus a disk containing the initial ramdisk, which will be /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ prompted for at boottime. /\/\/\/\/\/\/ If you wish to remaster the CD, please don't forget to specify /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/* -no-emul-boot -boot-load-size 4 -boot-info-table \ /\/\/\/\/\/\/\/\/\/\/\/\/* -b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat /\/\/\/\/\/\/\/\/\/\/\/\/\/\ as option to mkisofs. Otherwise your CD won't be bootable. /\/\/\/\/\/\/\/\/\/\/\/\/\/\/ [download] I still can't understand the use of having different names for the same script. Where are you keeping the default patterns? Landlords production is only eaten by landlords... Wherever I lay my KNOPPIX disk, a new FREE LINUX nation could be established	[reply] [d/l]
Re^2: Plaintext underlining tool by martin (Friar) on Jan 29, 2006 at 07:46 UTC
chanio asked: I still can't understand the use of having different names for the same script. Where are you keeping the default patterns? The default patterns are hard coded into the script, namely: `-----` `=====` `~~~~~` `^^^^^` The idea of scripts or binaries using the name they are called by as a parameter is not altogether uncommon in a Unix-like environment, a prominent example being your login shell that knows it is a login shell rather than an ordinary subshell from the fact that what appears to be its name starts with a dash. In such an environment the Perl function exec lets you choose the name argument (which will end up as `$0` in the called program) independently of the program's actual filename (using the indirect object syntax). The easiest way to take advantage of a `$0`-aware script from the command line, however, is to make it accessible via appropriate different filenames. Just link (or copy) your `pul.pl` file to `aul.pl` and see what happens if you call that (N.B. without a pattern argument).	[reply]
Re^3: Plaintext underlining tool by chanio (Priest) on Jan 31, 2006 at 00:27 UTC
`{qw(a - b = c ~ d ^)}->{substr($0, 0, 1)} \|\| shift;` [download] It is amazing! Linux & Perl always have a new surprise for me! Thank you! Landlords production is only eaten by landlords... Wherever I lay my KNOPPIX disk, a new FREE LINUX nation could be established	[reply] [d/l]