Re: perl regex to match newline followed by number and text

I am having trouble understanding the problem statement. You data was not enclosed in <code>..</code> tags and that is a problem. I don't really understand what removing the newlines in the 4th field means?

This is just a wild guess on my part - I guess that extra new lines meant spacers between these records - but maybe not?:

use strict;
use warnings;

my $line;

while (<DATA>)
{
   chomp;
   if ( (/:$/../^\s*$/) =~ /^\d+$/) #exclude endpoint.
   {
       s/\s,\s/,/;
       $line .= " $_";
   }
   elsif (defined $line)
   {
       $line =~ s/^\s*//;
       print "$line\n";
       $line = undef;
   }
} 
print "$line\n" if defined $line; # just to be sure
                                  # all output is done

=prints
99~Arun~Kumar~Mobilenum: 1234-567,from Earth Human
98~Mahesh~Babu~Mobilenum: 5678-901,from Earth Human
98~Mahesh~Babu~Mobilenbbb: 5678-901,from Earth Human
=cut


__DATA__ 
99~Arun~Kumar~Mobilenum:
1234-567 , from Earth
Human


98~Mahesh~Babu~Mobilenum:
5678-901 , from Earth
Human

98~Mahesh~Babu~Mobilenbbb:
5678-901 , from Earth
Human
[download]

I guess something very, very simple like this is possible? 3 input lines to one output line?

use strict;
use warnings;

my $input = do {local $/; <DATA>};
my @lines = $input =~ m/(.*\n.*\n.*\n)/g;
foreach my $line (@lines)
{
   $line =~ s/\n/ /g;
   $line =~ s/ , /,/g;
   print "$line\n";
}

=Prints
99~Arun~Kumar~Mobilenum: 1234-567,from Earth Human 
98~Mahesh~Babu~Mobilenum: 5678-901,from Earth Human 
98~Mahesh~Babu~Mobilenbbb: 5678-901,from Earth Human 
=cut


__DATA__ 
99~Arun~Kumar~Mobilenum:
1234-567 , from Earth
Human
98~Mahesh~Babu~Mobilenum:
5678-901 , from Earth
Human
98~Mahesh~Babu~Mobilenbbb:
5678-901 , from Earth
Human
[download]

Comment on Re: perl regex to match newline followed by number and text Select or Download Code

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Re^2: perl regex to match newline followed by number and text by holli (Abbot) on Jun 01, 2019 at 11:57 UTC
I guess something very, very simple like this is possible? 3 input lines to one output line? Good idea, but why then still use a regex? `while (<DATA>) { chomp; print; print $. % 3 ? " " : "\n"; } __DATA__ 99~Arun~Kumar~Mobilenum: 1234-567 , from Earth Human 98~Mahesh~Babu~Mobilenum: 5678-901 , from Earth Human` [download] Output `99~Arun~Kumar~Mobilenum: 1234-567 , from Earth Human 98~Mahesh~Babu~Mobilenum: 5678-901 , from Earth Human` [download] holli You can lead your users to water, but alas, you cannot drown them.	[reply] [d/l] [select]
Re^3: perl regex to match newline followed by number and text by arunkumarzz (Novice) on Jun 01, 2019 at 18:07 UTC
The number of newlines is not fixed, it might be one or two or three or more newlines in the last field	[reply]
Re^4: perl regex to match newline followed by number and text by holli (Abbot) on Jun 01, 2019 at 18:29 UTC
it might be one or two or three or more newlines in the last field Well it'd be nice if your sample data would reflect that. Anyhow. I'd solve this using a simple algorithm rather than a complicated regex that backtracks god knows how often with all these .* Consider: `use warnings; use strict; my @record; while (<DATA>) { if (/^\d+\~/ && @record) { print join (" ", @record), "\n"; @record = (); } chomp; push @record, $_; } print join (" ", @record), "\n"; __DATA__ 99~Markus~Holli~Mobilenum: 1234-567 , from Earth Europe White Human 98~Mahesh~Babu~Mobilenum: 5678-901 , from Earth India Brown Human` [download] Output `99~Markus~Holli~Mobilenum: 1234-567 , from Earth Europe White Human 98~Mahesh~Babu~Mobilenum: 5678-901 , from Earth India Brown Human` [download] holli You can lead your users to water, but alas, you cannot drown them.	[reply] [d/l] [select]