Perl script to read a tab delimited text file

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

I have a script which reads a tab delimited text file. The text file looks something like:
11811 NAME1 AGE1 LOCATION1 12156 NAME2 AGE2 LOCATION2 17899 NAME3 AGE3 LOCATION3 ... and so on I don't have problem reading the file, infact I can successfuly read and store it in an array too. My code is:

open(DAT,"C:\\StudyPerl\\Projects\\tab_file.txt") || die "Could not op
+en the file";
my @line;
my @array1;

while(<DAT>){
    @line = split(/\t/,$_);
    $array1[0]=$line[0];
    $array1[1]=$line[1];
    $array1[2]=$line[2];
    $array1[3]=$line[3];
}

foreach $1 (@array1){
    print "The element is: $1\n";
}
[download]

My problem is: I want the script to treat the variable after every 4 words as a new record.
I mean I want to store: 11811, NAME1, AGE1 & LOCATION1 in array1 and
12156, NAME2, AGE2 & LOCATION2 in array2 and so on.
Also, some words can be blank spaces, I need to handle them too. Basically, whenever there is/are any blank space(s), the array should store it as it is.
Can someone help me on that?

Comment on Perl script to read a tab delimited text file Select or Download Code

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Re: Perl script to read a tab delimited text file by maa (Pilgrim) on Apr 01, 2004 at 11:54 UTC
I don't see what your problem is... if the records are "fixed width" (i.e. there are 8 fields per line) then just check for define'dness of $line4 which should be the id of the 2nd part of the record... then save that record however you were going to savr the previous one. You should note, however, that your code is only every going to save the last record you read as you have hard-coded the array/indices in your while loop. :-) Why don't you consider using a hash where the key is the numeric ID and the content is an anon array? `while(<DAT>){ @line = split(/\t/,$_); $myhash{$line[0]} = [$line[1],$line[2],$line[3]]; }` [download] And have you actually tried your split on tab separated nothingness? HTH - Mark	[reply] [d/l]
Re: Perl script to read a tab delimited text file by Happy-the-monk (Canon) on Apr 01, 2004 at 11:55 UTC
I think you might be looking for something similar to this: `while ( <DAT> ) { my @line = split( /\t/, $_ ); while ( @line ) { my @four_records = splice( @line, 0, 4 ); # think "4 x shift( +@line )" push @array_of_arrays, [ @four_records ]; # make this an array + containing an array of four elements in each array slot. } }` [download] Cheerio, Sören	[reply] [d/l]
Re: Re: Perl script to read a tab delimited text file by Happy-the-monk (Canon) on Apr 01, 2004 at 13:30 UTC
Browsing through the nearly-new uploads to CPAN I found across `Array::Each - iterate over one or more arrays, returning one or more`. That's more a FYI, I think using it in this context would just overcomplicate it, I feel it has it's use when things get much more intricate. Cheers, Sören	[reply]
Re: Perl script to read a tab delimited text file by dragonchild (Archbishop) on Apr 01, 2004 at 12:54 UTC
When reading xSV data (x-Separated Values) where x is any single character, it is generally unwise to handle it naively using split. Much better is to use one of the many modules designed for this. The best is Text::xSV, by our own tilly. ------ We are the carpenters and bricklayers of the Information Age. Then there are Damian modules.... sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon.* - flyingmoose	[reply]
Re: Perl script to read a tab delimited text file by borisz (Canon) on Apr 01, 2004 at 11:54 UTC
`my @array; while ( defined ( $_ = <DAT> ) ) { push @array, /\t*((?:[^\t]+\t+){3}(?:[^\t]+))/g; }` [download] Boris	[reply] [d/l]
Re: Perl script to read a tab delimited text file by Crian (Curate) on Apr 01, 2004 at 14:16 UTC
Just a general hint: I think it's a good idea to print the reason ($!) when the opening (or else) of a file fails. Because it gives the user a hint, whats going wrong. Also it's helpful to name the file... If you use q(...) or '...', you don't need to double the backslash. All three tipps together remain in something like `my $file = 'C:\StudyPerl\Projects\tab_file.txt'; open(DAT, $file) or die "Could not open the file '$file': $!";` [download] hth	[reply] [d/l]