CODEWITHSUNDEEP
perlsubstitution
Steven
Steven

Reputation: 25

perl substitute numbers to alphabet,used with for

Perl substitute all Numbers to Alphabet

abc4xyz5u

to

abcdxyzeu

I try this,but it not work:

echo 'abc4xyz5u' | perl -pe'@n=1..9;@a=a..j;@h{@n}=@a;s#$n[$_]#$h{$&}#g for 0..$#n'

I know y/[1-9]/[a-j]/, but I want to use a substitute.

Upvotes: 2

Views: 379

Answers (2)

Dada
Dada

Reputation: 6626

Your issue is within 

s#$n[$_]#$h{$&}#g for 0..$#n

You expect $_ to be your input (so that s### is applied on it), but also $n[$_] to use the $_ from the for loop (0 to $#n). If you were to add a print, you'd notice that $_'s value within this loop is 0 to $#n, rather than your input.

What you could do instead to fix it is something like:

$r=$_; $r=~s#$n[$_]#$h{$&}#g for 0..$#n; $_=$r

But that's much more complicated that it has to be. I would instead do:

s#([1-9])#$h{$1}#g

Or, without using %h (since, let's face it, an hash with 0 => a, 1 => b etc. should be an array):

perl -pe '@a="a".."j"; s#([1-9])#$a[$1-1]#g'

Or, without requiring an array at all (I'll let you decide if you find it easier or harder to read; personally I'm fine with it), 

perl -pe 's/([1-9])/chr(ord("a")+$1-1)/ge'

Upvotes: 3

rai-gaurav
rai-gaurav

Reputation: 556

I would suggest to write it properly as a perl script. The one liner you mentioned is little hard to understand.

use strict;                                                            
use warnings;

my @alphabets = ("a".."z");

my $input = $ARGV[0];

$input =~ s/(\d)/$alphabets[$1 - 1]/g;

print $input;

Run -

perl substitute.pl abc4xyz5u

Output -

abcdxyzeu

I am serching for the number in the string and replacing it with the alphabet on the same position(remenber array start form 0 index and hence 'position -1') in the 'alphabets' array

Upvotes: 1

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