sandy105 has asked for the wisdom of the Perl Monks concerning the following question:

i have a script which just reads a file and depending upon a keyword i just write selected line to an output file

however i am not getting the expected output

use warnings;

my @lines;
my $mess;

open(hanr,"splitin.pl")or die"error $!\n";
open hanw, ">", "output.csv" or die $!;

@lines = <hanr>;

  foreach my $line (@lines) {
            chomp($line);
              $line =~ /^\$outcome /x or next; 
              my $Length = -2;
              my $mess = substr $line , 10 ,$Length;
              print hanw "$mess , \n";
              }
             
              
close hanr;
close hanw;

[download]

upon checking even after chomp i am getting lines such as these 

  if ( $prevseg ne "Iaw" ) 
  { 
    $outcome="alT - spi - Script $0 aborted. new Error Code: 022.  ";

[download]

because of indentation the regex fails , but i am puzzled as to why chomp doesnt work ?? ; why it does'nt remove the white spaces

Replies are listed 'Best First'.
Re: Chomp not working
by Athanasius (Archbishop) on Sep 24, 2014 at 08:47 UTC

    Hello sandy105,

    chomp removes the trailing newline from a string, if there is one; otherwise, it does nothing (unlike chop, which removes the final character from a string). To remove initial whitespace, you need something like this:

    $line =~ s/^\s+//;

    [download]

    Hope that helps,

    Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

[reply]
[d/l]
Re: Chomp not working (Path::Tiny lines spew)
by Anonymous Monk on Sep 24, 2014 at 09:15 UTC
    Path::Tiny has chomp option :) also "or dies" on error ... here is pretty much the same code 
    #!/usr/bin/perl --
use strict; use warnings;
use Path::Tiny qw/ path /;
my @lines = path( "splitin.pl" )->lines( { chomp => 1 } );
s/\s+$// for @lines; ## extra "chomp", trim trailing whitespace
s/^\s+// for @lines; ## trim leading whitespace
@lines = grep /^\$outcome /x, @lines;
@lines = map { substr( $_, 10, -2 )."\n" } @lines;
path( "output.csv" )->spew( @lines );
undef @lines;

    [download]
[reply]
[d/l]
Re: Chomp not working
by misterperl (Friar) on Sep 24, 2014 at 14:59 UTC
    # consider some changes to make your life easier 
    
# process the input and be done with it...
die"error $!\n" unless open hanr,"splitin.pl";
my @lines = <hanr>;
close hanr;

my $r = ''; # its easier to debug when you have a scalar you can print
+ later, rather than printing line by line...

  for my $line ( @lines ) {
# odd since $outcome is undef .. ?
      next unless $line =~ /^\$outcome /x;
      $line =~ s/.{9,9}(.+)../$1/; # get the middle chars
      $r .= $line; #append

     # print hanw "$mess , \n" # why chomp then add \n back in? Just l
+eave it there....;
     }
     

# process the output here
die $! unless open hanw, ">output.csv";
print hanw $r;
close hanw;

    [download]
[reply]
[d/l]
      $outcome is a literal "$outcome that i want to check for ; see i have escaped $ /^\$outcome/
[reply]
Re: Chomp not working
by codiac (Beadle) on Sep 29, 2014 at 01:03 UTC
    If you want to remove leading and trailing white space, that is trim. https://metacpan.org/pod/String::Util#trim-string

    If you want to trim and flatten internal white space, that is crunch. https://metacpan.org/pod/String::Util#crunch-string

[reply]

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