Re: I want to write a function, you call it ,it will return one matched record each time!

Welcome to the monastery.

I read your post which looked like this:

----- OP's original post starts ----------------------------

Hi there, I want to write a function that can return one record from a file ervery time, for example, the records in input.txt are like this:

_________________________
12 dd
DH: mm struct{
  int a;
  char b;
  m1 struct {
  int c;
  int d;
  };
  m2 struct {
  int e;
  int f;
  };
}
2 dfdkk
df
dd

}
1
    LOCAL_PARAM: ssi_struct {
ref = 0;
header = {
req = 0xa;
};
}



DH: mm struct{
  int a;
  char b;
  m1 struct {
  int c;
  int d;
  };
}
____________________________________
[download]

I want to use a function to extract the records starting with "DH:" each time I call it,like this $record = get_record("input.txt"); So I must remember the position of the file last read, and continue to extract the record. I use the seek and tell, but it didn't work. Here is the script:

sub get_record_from_file {
 my $filein = shift;
 my $regex = shift;
 my $pos = shift
 open FILEIN, "<$filein" or die "!$\n";
 seek(FILEIN, $pos, 0);
 my $in_block = 0;
 my $last = "}";
 my @array = {};
 
 foreach my $line (<FILEIN>) {
   if ($line =~ /$regex/) {
     $in_block = 1;
   }
   if ($in_block) {
     push @array, $line;
   }
   if ($line =~ m/$last$/) {
     $in_block = 0;
   }
  }
  $pos = tell FILEIN;
  return (\@array, $pos);
}

$record = get_record_from_file("input.txt","DH:",0);
[download]

Can anyone help? Thanks:)

----- OP's original post ends ------------------------------

I came up with a solution and clicked on the "Comment on" link to post it. I then found your posting had completely changed to this:

Please do not do this. If you want to cancel something you've posted, put <strike>...</strike> tags around the whole block of markup; add replacement text if that's appropriate; then add an Update: section which explains the changes you've made.

Here's my solution to your original problem:

#!/usr/bin/env perl

use strict;
use warnings;

my $sep = '=' x 60 . "\n";
(my $dh_file = $0) =~ s/pl$/dat/;
open_dh($dh_file);

while (1) {
    print 'Get next DH record (y/n): ';
    my $reply = <>;
    if ($reply =~ /^y/i) {
        print "Next DH record:\n";
        my $dh_record = read_dh();
        print "$sep$dh_record\n$sep";

        if (eof_dh()) {
            print "No more DH records!\n";
            last;
        } 
    }
    else {
        print "Stopped reading DH records.\n";
        last;
    }
}

close_dh();

{
    my $dh_fh;

    sub open_dh {
        my $dh_file = shift;
        open $dh_fh, '<', $dh_file or die "Can't read $dh_file: $!";
        my $discard = read_dh(); 
        return;
    }

    sub read_dh {
        local $/ = 'DH: ';
        my $dh_trim_re = qr{\A \s* (.*?) \s* (?: DH: \s )? \z}msx;
        my $dh_record = <$dh_fh>;
        $dh_record =~ s/$dh_trim_re/$1/;
        return $dh_record;
    }

    sub close_dh {
        close $dh_fh;
        return;
    }

    sub eof_dh {
        return eof $dh_fh;
    } 
}
[download]

Here's a sample run:

$ pm_get_multi_rec.pl
Get next DH record (y/n): y
Next DH record:
============================================================
mm struct{
  int a;
  char b;
  m1 struct {
  int c;
  int d;
  };
  m2 struct {
  int e;
  int f;
  };
}
2 dfdkk
df
dd

}
1
    LOCAL_PARAM: ssi_struct {
ref = 0;
header = {
req = 0xa;
};
}
============================================================
Get next DH record (y/n): y
Next DH record:
============================================================
mm struct{
  int a;
  char b;
  m1 struct {
  int c;
  int d;
  };
}
============================================================
No more DH records!
[download]

-- Ken

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