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

im a newbie and i want to replace https://abc.net/cm/one into https://abcde.net/dm/two in a text file im able to open and read the text file...for a single string im using $line =~ s/ABC/CDE/g; which works fine...but how do to the same for the path mentioned above..

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Re: Replace Strings
by NetWallah (Canon) on Feb 14, 2012 at 05:53 UTC
    Assuming you want some flexibility about your substitutions, you can use something like this: 
    use strict;
use warnings;

my @replace_by_level =(
  # Level 0 ----
  { "abc.net"        => "abcde.net",
    "something.else" => "Other.thing"},
  # Level 1 ---
  { cm  => "dm",
    dn  => "xx",
    ef  => "yy"},
  # Level 2 --
  { zero  => "one",
    one   => "two",
    two   => "three"},
  # Other levels as required ...
 );

my $orig_url = "https://abc.net/cm/one";

my ($transformed_url, $temp) = $orig_url =~m|(\w+://)(.+)|;

my $level=0;
$transformed_url .= join "/", map { $replace_by_level[$level++]{$_} } 
+split /\//, $temp;

print qq|$transformed_url\n|;     # https://abcde.net/dm/two

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    Checking whether the transformation exists, before applying it is left as an exercise.

                “PHP is a minor evil perpetrated and created by incompetent amateurs, whereas Perl is a great and insidious evil perpetrated by skilled but perverted professionals.”
            ― Jon Ribbens

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Re: Replace Strings
by kcott (Archbishop) on Feb 14, 2012 at 05:42 UTC

    Based on what you've provided, you can simply put your old and new URLs into variables and do the substitution the same way as you did with s/ABC/CDE/g. Here it is on the commandline: 

    ken@ganymede: ~/tmp
$ perl -Mstrict -Mwarnings -E '
> my $line = q{blah blah https://abc.net/cm/one blah blah};
> my $old_url = q{https://abc.net/cm/one};
> my $new_url = q{https://abcde.net/dm/two};
> $line =~ s/$old_url/$new_url/g;
> say $line;
> '
blah blah https://abcde.net/dm/two blah blah

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    -- Ken

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