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Re: replace all but first
by BrowserUk (Patriarch) on Sep 03, 2004 at 13:41 UTC
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my $s='aAaAaAaAaAaAAAAaaa';
substr( $s, 1+index( $s, 'A' ) ) =~ s[A][a]g;
print $s;
aAaaaaaaaaaaaaaaaa
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon
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[d/l] |
Re: replace all but first
by Roy Johnson (Monsignor) on Sep 03, 2004 at 14:30 UTC
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/A/g;
s/\G(.*?)A/$1a/g;
Another way:
s{(?<=A)(.*)}{my $rest=$1; $rest=~tr/A/a/; $rest}e;
Without regex:
substr($_, index($_, 'A')+1) =~ tr/A/a/;
And, combining techniques:
/A/g;
substr($_, ++pos) =~ tr/A/a/;
Caution: Contents may have been coded under pressure.
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[d/l]
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Re: replace all but first
by QM (Parson) on Sep 03, 2004 at 16:00 UTC
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[d/l] |
Re: replace all but first
by terra incognita (Pilgrim) on Sep 03, 2004 at 16:46 UTC
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Here is my solution. It is no where as elegant and short as the previous ones. Comments on where I can improve this code and what practices I should stay away from are appreciated.
use strict;
#OPEN FILE A.txt for READING (CHECK FOR FAILURES)
open (INFILE, "<","A.txt" ) or die "Could not open file A.txt: $!";
#OPEN FILE B.txt for WRITING (CHECK FOR FAILURES)
open (OUTFILE, ">","B.txt" ) or die "Could not open file B.txt: $!";
my $prev_country = "";
my $line;
my @myarray;
my $country;
my $company;
while ($line = <INFILE>) {
# SPLIT THE FILE BETWEEN COUNTRY AND COMPANY
@myarray = split /></,$line;
$country = $myarray[0];
# CHECK TO SEE IF THE CURRENT COUNTRY MATCHS THE PREVIOUS COUNTRY
if ($prev_country ne $country) {
#IF NEW COUNTRY PRINT WHOLE LINE
print OUTFILE "$line";
$prev_country = ($country);
next;
}
# IF SAME COUNTRY PRINT ONLY COMPANY
$company = $myarray[1];
print OUTFILE "\t<$company";
}
close OUTFILE;
close INFILE;
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[d/l] |
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Not bad, but to keep it a little more re-usable and flexible (suppose, for instance, more tags/values are added later), you can do away with the $company and $country variables altogether, and do:
...
@myarray = split /></,$line;
if ( $prev ne $myarray[0] ) {
$prev = $myarray[0];
} else {
$myarray[0] = "<TAB";
}
$line = join '><', @myarray;
print OUTFILE, $line;
...
This also takes care of the fact that I think the original author meant <TAB> literally. If I'm wrong, insert this after the join:
$line =~ s/<TAB>/\t/;
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Re: replace all but first
by DigitalKitty (Parson) on Sep 04, 2004 at 08:39 UTC
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Re: replace all but first
by Grygonos (Chaplain) on Sep 03, 2004 at 13:43 UTC
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Firstly, there isn't much information you've given us. The layout of the file may be helpful. Secondly, I would reccomend using tr rather than s (see perlop). Since you are not replacing, but rather transliterating. However, if you wanted to replace a with ABBA (haha) then you would want to use the s operator.
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[d/l]
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This is what i am trying to do
my text file has
<cnt>Germany</cnt><cmp>ALLIANZ INSURANCE</cmp>
<cnt>Germany</cnt><cmp>ALLIANZ PARKWAY</cmp>
<cnt>Germany</cnt><cmp>ALLIED DOMECQ</cmp>
i want to replace it as
<cnt>Germany</cnt><cmp>ALLIANZ INSURANCE</cmp>
<TAB><cmp>ALLIANZ PARKWAY</cmp>
<TAB><cmp>ALLIED DOMECQ</cmp>
i.e. i want to replace "<cnt>Germany</cnt>" to "<TAB>" from its second occurance
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use strict;
use warnings;
my %seen;
while ( <DATA> ) {
next unless /^(<cnt>([^<]+)<\/cnt>)(.*)$/;
print $seen{$2}++ ? "<TAB>$3\n" : "$1$3\n";
}
__DATA__
<cnt>France</cnt><cmp>ACCOR</cmp>
<cnt>France</cnt><cmp>AGF</cmp>
<cnt>France</cnt><cmp>AIR LIQUIDE</cmp>
<cnt>Germany</cnt><cmp>ALLIANZ INSURANCE</cmp>
<cnt>Germany</cnt><cmp>ALLIANZ PARKWAY</cmp>
<cnt>Germany</cnt><cmp>ALLIED DOMECQ</cmp>
<cnt>United Kingdom</cnt><cmp>LEICESTER CITY FOOTBALL CLUB</cmp>
<cnt>United Kingdom</cnt><cmp>SPENCER GEARS</cmp>
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[d/l] |
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If it's not going to appear twice on the same line:
my $seen=0;
while(<DATA>) {
if ($seen) { s{<cnt>Germany</cnt>}{<TAB>} }
else { $seen ||= m{<cnt>Germany</cnt>} }
print;
}
__DATA__
<cnt>Germany</cnt><cmp>ALLIANZ INSURANCE</cmp>
<cnt>Germany</cnt><cmp>ALLIANZ PARKWAY</cmp>
<cnt>Germany</cnt><cmp>ALLIED DOMECQ</cmp>
Caution: Contents may have been coded under pressure.
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[d/l] |
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$data =~ s{(<cnt>Germany</cnt>)}{$seen++?'<TAB>':$1}ge;
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[d/l] |