I am trying to learn how tr really works, and I think I still don't get it. I remember, reading the manual...it said that the character following tr is a separator character, and everything between the separators are characters that will get replaced with a new set of characters defined in the second group. Anyway, I am trying to write a little program that replaces the first 52 bytes of a character map with letters. In other words, in this programming exercise, I am trying to replace binary codes with tr, but tr is not handling these codes very well. For example, it gives an error when I try to convert chr(8) to "I"

Here is my sample code: 


#!/usr/bin/perl

use strict;
use warnings;

for (my $i = 0; $i < 52; $i++)
{
  $a = chr($i);
  $a =~ tr|\0\1\2\3\4\5\6\7\8\t\n\0x0B\r\0x0D\0x0E\0x0F\0x10\0x11\0x12
+\0x13\0x14\0x15\0x16\0x17\0x18\0x19\0x1A\0x1B\0x1C\0x1D\0x1E\0x1F !"#
+$%&'()*+,-./0123456789|ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrst
+uvwxyz|;
  print "chr $i -> $a \n";
}

exit;

[download]

In reply to Question about tr by harangzsolt33

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.