perl substitue till found pattern in aline

Vijay81 has asked for the wisdom of the Perl Monks concerning the following question:

Hi All, Am trying to substitute a comma in place of space in a line but till find the pattern. First part able to do but don't know how to do the part 2. Any help please

Script reads files(*.bat) from a perticular directory and read the content and substutite space with comma. bat file will have the pattern "-1". now i need subsutitue comma till find this pattern

bat file content :

01 fines name 2222 -P sws -1 reee.tee rrt
02 fi si 2232 -P sqww -1 re.wqw ttf
[download]

Main script content :

#!/usr/bin/perl
use warnings; 
use strict;
use Class::CSV;
my ($csv, $inputfilename, $resultfile, $fh, $line, $dir, $fp, $count);
$dir = 'C:\TestData';
open $resultfile, '>>', 'input.csv' or die "Can't open file: $!";
foreach $fp (glob("$dir/*.bat")) {
  #printf "%s\n", $fp;
  open ($fh, "<", $fp) or die "can't read open '$fp':";
    
  while ($line = <$fh>) {
  #$line=~s/-l//;
    $line=~ s/ /,/g;
    print $resultfile $line;
    print $resultfile "\n";
    print $line;
  }
}
  close $fh or die "can't read close '$fp':";
[download]

output file should look like :

01,fines,name,2222,-P,sws -1 reee.tee rrt
02,fi,si,2232,-P,sqww,-1 re.wqw ttf
[download]

Comment on perl substitue till found pattern in aline Select or Download Code

Replies are listed 'Best First'.
Re: perl substitue till found pattern in aline by rjt (Curate) on Dec 02, 2012 at 18:33 UTC
`while (<DATA>) { s/ (?=.*\s?-1 )/,/g; print; } __DATA__ 01 fines name 2222 -P sws -1 reee.tee rrt 02 fi si 2232 -P sqww -1 re.wqw ttf 02 fi si-1 2232 -P sqww -1 re.wqw ttf` [download] This will replace spaces with commas before the last -1 in the file.	[reply] [d/l]
Re^2: perl substitue till found pattern in aline by pushtaev (Sexton) on Dec 03, 2012 at 06:26 UTC
This variant is a little bit more easy to read and should be executed faster. `while (<DATA>) { my ( $left, $right ) = split /-1/, $_, 2; $left =~ s/ /,/g; print join '-1', $left, $right; } __DATA__ 01 fines name 2222 -P sws -1 reee.tee rrt 02 fi si 2232 -P sqww -1 re.wqw ttf 02 fi si-1 2232 -P sqww -1 re.wqw ttf` [download]	[reply] [d/l]
Re^3: perl substitue till found pattern in aline by rjt (Curate) on Dec 03, 2012 at 08:57 UTC
Hi! Your code is slower by about a factor of 3: `use Benchmark qw/:all :hireswallclock/; my $DATA = '01 fines name 2222 -P sws -1 reee.tee rrt'; cmpthese(-10, { 'rjt' => q{ $_ = $DATA; s/ (?=.*\s?-1 )/,/g; }, 'pushtaev' => q{ $_ = $DATA; my ( $left, $right ) = split /-1/, $_, 2; $left =~ s/ /,/g; join '-1', $left, $right; }, });` [download] `Rate pushtaev rjt pushtaev 1875006/s -- -75% rjt 7582716/s 304% --` [download] Regarding readability, it will depend who you ask in this case. In my experience, I tend to find a simple regex easier to read than tearing apart and piecing a solution back together with `split, s///, and join`. Lastly, in your code, replacing this: `print join '-1', $left, $right;` ... with this: `print $left, '-1', $right;` ... resulted in a 32% speed improvement before I/O on your solution (still ~2.2x slower than the straight regex) and puts the terms in their natural order, which is probably more readable than the strange use of `join` with a delimiter to concatenate three strings. I hope this is useful feedback to your feedback!	[reply] [d/l] [select]
Re: perl substitue till found pattern in aline by johngg (Canon) on Dec 02, 2012 at 19:24 UTC
Your example output seems to be inconsistent. In the first line the space before the '-1' is not substituted with a comma but in the second it is. Please could you clarify your requirement. Cheers, JohnGG	[reply]
Re^2: perl substitue till found pattern in aline by Vijay81 (Acolyte) on Dec 03, 2012 at 08:36 UTC
Sorry it was typo mistake `01,fines,name,2222,-P,sws,-1 reee.tee rrt 02,fi,si,2232,-P,sqww,-1 re.wqw ttf` [download]	[reply] [d/l]