A one liner:

perl -F; -anle"$F[0] ne $last and open F, '>', $F[0].'.csv'; print F; 
+$last = $F[0]" junk.dat

C:\test>dir *.csv
30/05/2012  23:17               204 Albani‰.csv
30/05/2012  23:17               194 Andorra.csv
30/05/2012  23:17               325 Belgi‰.csv
30/05/2012  23:17               394 Engeland.csv
30/05/2012  23:17               295 Finland.csv
30/05/2012  23:17               332 Frankrijk.csv

C:\test>type Albani‰.csv
Albanië;Albanië;Berat;Hotel;Berati;40,9999;19,99999;Meer;ok;0;
Albanië;Albanië;Berat;Hotel;Castle Park;45,769969;19,9999;Meer;ok;0;
Albanië;Albanië;Berat;Hotel;Mangalemi;40,709999;19,959999;Meer;ok;0;

C:\test>type Andorra.csv
Andorra;Andorra;El Serrat;Hotel;Subi;43,658607;5,568623;;ok;0;
Andorra;Andorra;El Serrat;Hotel;Tristan;42,618507;1,538923;;ok;0;
Andorra;Andorra;El Tarter;Hotel;Del;42,580340;1,648919;;ok;0;

C:\test>type Belgi‰.csv
België;Antwerpen;Antwerpen;Bezienswaardigheid;Boerentoren (Kbc Toren);
+51,2000;4,399000;;ok;0;
België;Antwerpen;Antwerpen;Bed&Breakfast;Borze;51,2200;4,399000;;ok;0;
België;Antwerpen;Antwerpen;Bed&Breakfast;Boulevard ;51,220000;4,399000
+;;ok;0;
België;Antwerpen;Antwerpen;Appartement;Britselei 37;51,220000;4,399000
+;;ok;0;
[download]

perl -F';' -ane'open F, ">>$F[0].csv" and print F' junk.dat
[download]

Nice golfing :)

You'd have to remember to delete the output files before a re-run; and if the input is big, reopening the output files would likely be a significant factor.

I kept thinking about the one-arg open, but I couldn't make it work with an array element.

---

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?

#!/usr/bin/perl
use strict;
use warnings;

my %countries;
open my $IN, '<:encoding(utf-8)', '1.csv' or die $!;
while (<$IN>) {
    my @columns = split /;/;
    push @{ $countries{$columns[0]} }, $_;
}

for my $country (keys %countries) {
    open my $OUT, '>:encoding(utf-8)', "$country.csv" or die $!;
    for (@{ $countries{$country} }) {
        print {$OUT} $_;
    }
    close $OUT or die $!;
}
[download]

Hi, i'm trying to understand what you created and piece by piece i'm putting it together. But when i run it i get the following error.

utf8 "\xEB" does not map to Unicode at C:\bla\bla\bla line 9, <$IN> line XXXX.

So i'm guessing this has something to do with the encoding. I'm not sure what kind of encoding i use. Is there a way to look this up in my file? Or is it possible to remove the encoding part? , '<:encoding(utf-8)' so it will read it as a normal file perhaps? Because i didn't need it before.

@ BrowserUk / jwkrahn: i dont have enough experience to work with your answers i'm afraid

edit: When i remove the encoding part i get this: No such file or directory at Z:\Data-Content\Data\test\jan\ALL_DATA\ori.pl line 13, <$IN> line 50001. (line 50001 being the end of the input file). What am i doing wrong?

Have you removed the : as well? The open should look like

open my $IN, '<', '1.csv' or die $!;
[download]

awk -F";" '{print >$1 ".csv"}' file.csv
[download]

Depending somewhat on how the file was created it may not be sufficient to simplistically parse each line by splitting on semi-colons. If it is a well formed csv file you should use one of the CSV modules such as Text::CSV to manage parsing the file. Consider:

use strict;
use warnings;
use Text::CSV qw{};

# Create a test file
my $fname = 'delme.csv';

open my $fOut, '>', $fname or die "Can't create $fname: $!\n";
print $fOut <<'TESTDATA';
country_name;region;city;type;area;lat;long;etc
Albanië;Albanië;Berat;Hotel;Berati;40,9999;19,99999;Meer;ok;0;
Albanië;Albanië;Berat;Hotel;Castle Park;45,769969;19,9999;Meer;ok;0;
Albanië;Albanië;Berat;Hotel;Mangalemi;40,709999;19,959999;Meer;ok;0;
Andorra;Andorra;El Serrat;Hotel;Subi;43,658607;5,568623;;ok;0;
Andorra;Andorra;El Serrat;Hotel;Tristan;42,618507;1,538923;;ok;0;
Andorra;Andorra;El Tarter;Hotel;Del;42,580340;1,648919;;ok;0;
België;Antwerpen;Antwerpen;Bezienswaardigheid;Boerentoren (Kbc Toren);
+51,2000;4,399000;;ok;0;
België;Antwerpen;Antwerpen;Bed&Breakfast;Borze;51,2200;4,399000;;ok;0;
België;Antwerpen;Antwerpen;Bed&Breakfast;Boulevard ;51,220000;4,399000
+;;ok;0;
België;Antwerpen;Antwerpen;Appartement;Britselei 37;51,220000;4,399000
+;;ok;0;
Engeland;Groot Londen;Londen;Museum;Tate Britain;51,5200;-0,126236;;ok
+;0;
Engeland;Groot Londen;Londen;Museum;Tate Modern;51,500200;-0,126236;;o
+k;0;
Engeland;Groot Londen;Londen;Hotel;Testing;51,500200;-0,126236;;ok;0;
Engeland;Groot Londen;Londen;Bezienswaardigheid;Thames (rivier);51,020
+0;-0,126236;;ok;0;
Engeland;Groot Londen;Londen;Hotel;The Archery London;51,500200;-0,126
+236;;ok;0;
Finland;Finland;Ylläsjärvi;Hotel;Yllasrinne;67,526750;24,275630;;ok;0;
Finland;Finland;Ypäjä;Bezienswaardigheid;Loimijoki Golf;0,805300;23,27
+1400;;ok;0
Finland;Finland;Ytteresse;Vakantiepark;Solhaga;0,630700;22,962500;;ok;
+0
Finland;Lapland;Hetta;Hotel;Hetan Majatalo;6,34700;23,633800;;ok;0
Frankrijk;Alsace (Elzas);Rouffach;Hotel;Au Relais D'Alsace;7,959680;7,
+29970;;ok;0
Frankrijk;Alsace (Elzas);Rouffach;Hotel;Château d Isenbourg;7,959680;7
+,29970;;ok;0
Frankrijk;Alsace (Elzas);Ruederbach;Vakantiehuis;Au Cheval Blanc;47,56
+1440;7,26840;;ok;0
Frankrijk;Alsace (Elzas);Sausheim;Camping;Le fary;4,787300;7,36390;;ok
+;0;
TESTDATA
close $fOut;

# Now for the sample interesting code
open my $fIn, '<', $fname or die "Can't open $fname: $!\n";

my $csv = Text::CSV->new({binary => 1, sep_char => ';'});
my %byCountry;
my @columns = @{$csv->getline($fIn)};

push @{$byCountry{$_->[0]}}, $_ while $_ = $csv->getline($fIn);
close $fIn;

for my $country (sort keys %byCountry) {
    print "--- $country.csv---\n";
    $csv->print (*STDOUT, \@columns);
    print "\n";

    for my $row (@{$byCountry{$country}}) {
        $csv->print (*STDOUT, $row);
        print "\n";
    }
}
[download]

Prints (in part):

--- Albanië.csv---
country_name;region;city;type;area;lat;long;etc
Albanië;Albanië;Berat;Hotel;Berati;40,9999;19,99999;Meer;ok;0;
Albanië;Albanië;Berat;Hotel;"Castle Park";45,769969;19,9999;Meer;ok;0;
Albanië;Albanië;Berat;Hotel;Mangalemi;40,709999;19,959999;Meer;ok;0;
--- Andorra.csv---
country_name;region;city;type;area;lat;long;etc
Andorra;Andorra;"El Serrat";Hotel;Subi;43,658607;5,568623;;ok;0;
...
Finland;Finland;Ypäjä;Bezienswaardigheid;"Loimijoki Golf";0,805300;23,
+271400;;ok;0
Finland;Finland;Ytteresse;Vakantiepark;Solhaga;0,630700;22,962500;;ok;
+0
Finland;Lapland;Hetta;Hotel;"Hetan Majatalo";6,34700;23,633800;;ok;0
--- Frankrijk.csv---
country_name;region;city;type;area;lat;long;etc
Frankrijk;"Alsace (Elzas)";Rouffach;Hotel;"Au Relais D'Alsace";7,95968
+0;7,29970;;ok;0
Frankrijk;"Alsace (Elzas)";Rouffach;Hotel;"Château d Isenbourg";7,9596
+80;7,29970;;ok;0
Frankrijk;"Alsace (Elzas)";Ruederbach;Vakantiehuis;"Au Cheval Blanc";4
+7,561440;7,26840;;ok;0
Frankrijk;"Alsace (Elzas)";Sausheim;Camping;"Le fary";4,787300;7,36390
+;;ok;0;
[download]

Also see part - split up files according to column value, which could handle the heavy lifting. It has no provisions for handling UTF-8 data or other encodings, so you might want to modify it to open the input file with the appropriate encoding:

binmode ARGV, ':utf8'; # if your input is encoded as UTF-8
[download]

For generating the output filenames, I prefer ASCII filenames, so I'd use Text::CleanFragment or the underlying Text::Unidecode to generate filesystem-clean filenames from values.