Sorting Books

I wrote a little program to sort lists of books.

Over the weekend I was tidying up my note on books to read. I try to track what I want to read, who recommended it, and when they recommended it. I used to just try to manually keep stuff in alphabetical order but that always eventually got messed up. I finally decided that I wanted to sort the lines properly (after organizing the list into tables instead of nested lists.)

I’m pleased with what I came up with. First I made a tool called book-sorter, which prepends each line with a normalized version; here it is:

#!/usr/bin/perl

use strict;
use warnings;

no warnings 'uninitialized';

use feature 'fc';

while (<STDIN>) {
   my $v = $_;
   $v =~ s/^\W+//;
   $v =~ s/^(the|a|an)\b//i;
   $v =~ s/^\W+//;
   $v = fc $v;

   chomp $v;
   print "$v\0$_"
}

So this transforms each line in a streaming fashion, stripping non-word characters, then articles (a, an, or the), and finally any more non-word characters. Finally it case-folds the string so comparisons will be case-insensitive. I could have lowercased, but this will work better with non-ascii.

Next I build a script called book-sort that uses book-sorter:

#!/bin/sh

bin/book-sorter |
   sort |
   cut -d "$(printf "\0")" -f2

Pretty neat!

(The following includes affiliate links.)

If you’re interested in diving deeper than is probably wise in writing shell scripts, you should check out From Bash to Z Shell. The book has in depth coverage of all of the major POSIX shells and their non-POSIX features.

On a completely different note, I recently read Spy the Lie, suggested by Jess Frazelle. It was fascinating! I am a little nervous to put any such skills to use, but it’s better to know if someone is lying than to incorrectly assume they are being honest.

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