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Splitting Multiple files into arrays.

by devbond (Novice)
on Jul 20, 2013 at 20:42 UTC ( #1045467=perlquestion: print w/ replies, xml ) Need Help??
devbond has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to read a file and split(by space) into an array called values and finally puttin it into a array table.I am able to do it for a single file but i want to split 8 files in a loop one after the other into 8 different arrays..table1 table2....table 8.

But the following code below is not working. Please advise.

for (my $i = 1 ;$i <=8; $i++) { open (MYFILE,"server$i"); while (<MYFILE>) { chomp; my @values = split " ",$_; push @{ "table$i"},\@values; } }

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Re: Splitting Multiple files into arrays.
by mtmcc (Hermit) on Jul 20, 2013 at 20:55 UTC
    What does the data in your files look like, and what outcome do you expect to get?
      Date Value1 value2 value3 value 4 Date Value1 value2 value3 value 4 .. .. .. .. .. upto 25 times. i want to extract each value into an array element
Re: Splitting Multiple files into arrays.
by rjt (Deacon) on Jul 20, 2013 at 21:24 UTC
    But the following code below is not working.
        push @{ "table$i"}

    That's because you're trying to build a string and use it as an array ref. I strongly urge you to re-think your need to put everything into @array1, @array2, ...; this sort of logic is almost never a good idea. Use an array of array refs instead:

    use 5.012; use warnings; use autodie; my @array; for (glob 'file*.txt') { local $/; # Slurp my ($num) = /(\d+)\.txt$/g; open my $fh, '<', $_; $array[$num] = [ split /\s/m, <$fh> ]; } $" = '> <'; say "\$array[$_] = <@{$array[$_]}>" for 1..$#array;

    Output:

    $array[1] = <foo> <bar> <baz> $array[2] = <one> <two> <three> <four> <five> <six> $array[3] = <apple> <pear> <mango>

    But even at that, you may want to consider a hash of filenames, instead, as a more general solution:

    my %hash; for my $file (glob 'file*.txt') { local $/; # Slurp open my $fh, '<', $file; $hash{$file} = [ split /\s/m, <$fh> ]; } $" = '> <'; say "\$hash[$_] = <@{$hash{$_}}>" for keys %hash;

    Input files used

      I have a 2D File like the following and i have 8 such files which i have to put into 8 Arrays. 00:00 2453 10319 0 0 01:00 1565 626 0 0 02:00 1171 4195 0 0 03:00 1117 3597 4 0 04:00 1494 569 0 0 05:00 2873 0900 0 0 06:00 4899 2368 0 0 07:00 4251 9664 0 0 08:00 5791 8910 0 0 09:00 7068 0138 0 0 10:00 8464 3881 0 0 11:00 9610 5291 0 0 12:00 1017 8634 0 0 13:00 1090 8203 0 0 14:00 1322 9165 0 0

        That data is tab-delimited, not space-delimited. I'd use Text::CSV for this.

        use Text::CSV; my $csv = Text::CSV->new({ sep_char = "\t" }); my $array_ref = $csv->getline_all($fh); # OR... my @array = @{ $csv->getline_all($fh) };

        You can easily adapt the loop constructs I suggested, above, or many of the other suggestions given by others, with this approach. Good luck.

Re: Splitting Multiple files into arrays.
by jwkrahn (Monsignor) on Jul 20, 2013 at 21:49 UTC
    I am trying to read a file and split(by space) into an array called values and finally puttin it into a array table.I am able to do it for a single file but i want to split 8 files in a loop one after the other into 8 different arrays..table1 table2....table 8. But the following code below is not working. Please advise. for (my $i = 1 ;$i <=8; $i++) { open (MYFILE,"server$i"); while (<MYFILE>) { chomp; my @values = split " ",$_; push @{ "table$i"},\@values; } }
    use warnings; use strict; @ARGV = map "server$_", 1 .. 8; my %data; while ( <> ) { push @{ $data{ $ARGV } }, [ split ]; }
Re: Splitting Multiple files into arrays.
by mtmcc (Hermit) on Jul 20, 2013 at 21:50 UTC
    Maybe something like this?:

    #! /usr/bin/perl use strict; use warnings; my $x = 0; my %values; my @lines; my $lineNumber =0; my %parentHash; my @values; for ($x=1; $x<=6; $x += 1) { open (OUT, "<", "server$x"); while (<OUT>) { chomp; @lines = split(" ", $_); push (@{$parentHash{"server$x"}[$lineNumber]}, @lines) +; $lineNumber += 1; } $lineNumber = 0; close OUT; } #file line my @derefencedArray = @{$parentHash{"server2"}[2]}; print STDERR "@derefencedArray\n";

Re: Splitting Multiple files into arrays.
by Laurent_R (Parson) on Jul 20, 2013 at 23:03 UTC

    Please format your code to make it readable. This is your code correctly reformatted.

    for (my $i = 1 ;$i <=8; $i++) { open (MYFILE,"server$i"); while (<MYFILE>) { chomp; my @values = split " ",$_; push @{ "table$i"},\@values; } }
    In short, you are using symbolic references, which was right 15 years ago, but is deprecated and probably wrong today.

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