CODEWITHSUNDEEP
perlparsingtext-processing
prabhu
prabhu

Reputation: 929

Perl record separator -

I'm stuck on a seemingly trivial problem but not sure what is it that I'm missing. Need help.

I have a file that is delimited by the standard field separator (0x1f) and record separator (0x1e) characters. (https://en.wikipedia.org/wiki/Delimiter#ASCII_delimited_text)

I don't need to parse out the fields but interested in getting the records.

I read about Perl's record separator special variable and tried using that to parse the file.

The file looks like this. ^ represents the field separator and ^^ represents the record separator (in vim). On sublime these will show up as the relevant hex codes.

ID^_NAME^_PARENTID^_Prov ID^_Pat_ID^_Another ID^_Program1^_Program2^_Status^_Date^_Reason^_Added^_Sn Length^_ze Reason^_StAge^_EnAge^_Notes^^NUMBER^_VARCHAR^_NUMBER^_    NUMBER^_NUMBER^_NUMBER^_VARCHAR^_VARCHAR^_VARCHAR^_DATE^_VARCHAR^_VARCHAR^_VARCHAR^_VARCHAR^_VARCHAR^_VARCHAR^_VARCHAR^^12^_40^_12^_^_12^_12^_200^_200^_12^_^_200^_1^_    4000^_4000^_2000^_2000^_4000^^0^_^_0^_^_0^_0^_^_^_^_^_^_^_^_^_^_^_^^

Following is the code that I wrote to parse the records out. Issue is, whatever I do, the entire file is read into the $row scalar.

I initially assumed that perl expects the $/ to be set to a string type. Doing that also doesn't seem to work and I'm stuck.

Appreciate any help. Thanks.

#local $/ = sprintf("%s",chr("0xa"));
local $/ = chr(0xa);

open my $fh, "<", $file or die "$file: $!";

print("reading records\n");

while (my $row = <$fh>) {
    print("Record:", $row, "\n");
}

Upvotes: 0

Views: 555

Answers (1)

Schwern
Schwern

Reputation: 165208

You can use chr(0xNN), but it's simpler to write a hex character as "\xNN". A string containing record separator is "\x1e".

#!/usr/bin/env perl

use strict;
use warnings;
use v5.10;

my $file = shift;
open my $fh, "<", $file or die "$file: $!";

say "reading records";

local $/ = "\x1e";
while (my $row = <$fh>) {
    say("Record:", join ",", split /\x1f/, $row);
}

Upvotes: 3

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