Based on a mapping file, i need to search for a string and if found append the replace string to the end of line.
I'm traversing through the mapping file line by line and using the below perl one-liner, appending the strings.
Issues:
1.Huge find & replace Entries: But the issues is the mapping file has huge number of entries (~7000 entries) and perl one-liners takes ~1 seconds for each entries which boils down to ~1 Hour to complete the entire replacement.
2.Not Simple Find and Replace: Its not a simple Find & Replace. It is - if found string, append the replace string to EOL.
If there is no efficient way to process this, i would even consider replacing rather than appending.
Mine is on Windows 7 64-Bit environment and im using active perl. No *unix support.
File Samples
Map.csv
findStr1,RplStr1
findStr2,RplStr2
findStr3,RplStr3
.....
findStr7000,RplStr7000
input.csv
col1,col2,col3,findStr1,....col-N
col1,col2,col3,findStr2,....col-N
col1,col2,col3,FIND-STR-NOT-EXIST,....col-N
output.csv (Expected Output)
col1,col2,col3,findStr1,....col-N,**RplStr1**
col1,col2,col3,findStr1,....col-N,**RplStr2**
col1,col2,col3,FIND-STR-NOT-EXIST,....col-N
Perl Code Snippet
One-Liner
perl -pe '/findStr/ && s/$/RplStr/' file.csv
open( INFILE, $MarketMapFile ) or die "Error occured: $!";
my @data = <INFILE>;
my $cnt=1;
foreach $line (@data) {
eval {
# Remove end of line character.
$line =~ s/\n//g;
my ( $eNodeBID, $MarketName ) = split( ',', $line );
my $exeCmd = 'perl -i.bak -p -e "/'.$eNodeBID.'\(M\)/ && s/$/,'.$MarketName.'/;" '.$CSVFile;
print "\n $cnt Repelacing $eNodeBID with $MarketName and cmd is $exeCmd";
system($exeCmd);
$cnt++;
}
}
close(INFILE);
To do this in a single pass through your input CSV, it's easiest to store your mapping in a hash. 7000 entries is not particularly huge, but if you're worried about storing all of that in memory you can use Tie::File::AsHash.
#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV;
use Tie::File::AsHash;
tie my %replace, 'Tie::File::AsHash', 'map.csv', split => ',' or die $!;
my $csv = Text::CSV->new({ binary => 1, auto_diag => 1, eol => $/ })
or die Text::CSV->error_diag;
open my $in_fh, '<', 'input.csv' or die $!;
open my $out_fh, '>', 'output.csv' or die $!;
while (my $row = $csv->getline($in_fh)) {
push @$row, $replace{$row->[3]};
$csv->print($out_fh, $row);
}
untie %replace;
close $in_fh;
close $out_fh;
map.csv
foo,bar
apple,orange
pony,unicorn
input.csv
field1,field2,field3,pony,field5,field6
field1,field2,field3,banana,field5,field6
field1,field2,field3,apple,field5,field6
output.csv
field1,field2,field3,pony,field5,field6,unicorn
field1,field2,field3,banana,field5,field6,
field1,field2,field3,apple,field5,field6,orange
I don't recommend screwing up your CSV format by only appending fields to matching lines, so I add an empty field if a match isn't found.
To use a regular hash instead of Tie::File::AsHash, simply replace the tie statement with
open my $map_fh, '<', 'map.csv' or die $!;
my %replace = map { chomp; split /,/ } <$map_fh>;
close $map_fh;
This is untested code / pseudo-Perl you'll need to polish it (strict, warnings, etc.):
# load the search and replace sreings into memeory
open($mapfh, "<", mapfile);
%maplines;
while ( $mapline = <fh> ) {
($findstr, $replstr) = split(/,/, $mapline);
%maplines{$findstr} = $replstr;
}
close $mapfh;
open($ifh, "<", inputfile);
while ($inputline = <$ifh>) { # read an input line
@input = split(/,/, $inputline); # split it into a list
if (exists $maplines{$input[3]}) { # does this line match
chomp $input[-1]; # remove the new line
push @input, $maplines{$input[3]}; # add the replace str to the end
last; # done processing this line
}
print join(',', @input); # or print or an output file
}
close($ihf)
