sas429s has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I have a file which looks like this: 
maps_c7    190_520        3195927 00    40     0K8632
maps_c7    210_520        3195928 00    41     0K8701
maps_c7    210_620       3195929 00    42     0K8702
maps_c7    230_560        3195930 00    43     0K8635
maps_c7    230_620        3195931 00    44     0K8703
maps_c7    230_660        3195932 00    45     0K8704
maps_c7    250_660        3195933 00    46     0K8638
maps_c7    250_800        3195934 00    47     0K8705
maps_c7    275_800        3195935 00    48     0K8640
maps_c7    300_860        3195936 00    49     0K8706
maps_c7    300_860_ER     3195937 00    50     0K8642
maps_c7    330_860_ER     3195938 00    51     0K8643
maps_c7    350_860_ER     3195939 00    52     0K8707
maps_c7    300_860_RV     3195940 00    53     0K8645
maps_c7    330_860_RV     3195941 00    54     0K8646
maps_c7    350_860_RV    3195942 00    55     0K8647
maps_c7 360_925_RV    3195943    00    56     0K9048

[download]
My program has a problem..Why Can't I loop through each line of the file, I get to print only the first line. It might sound silly asking this question but whats problem with my foreach loop? 
#!/usr/bin/perl

use strict;
use warnings;
use Tie::File;
use Fcntl;

$ENV{HOME}='C:\Documents and Settings\kompeS\Desktop\PERL SCRIPTS';
my $file= "$ENV{HOME}/partno_C7_5.03.4_prod";
my @array;
my $line="";
my @data;
my $map_dir=""; 
my $dir=""; 
my $part_no="";
my $chg_lvl="";
my $int_lock="";
my $t_spec="";
my @list="";
my $formatted_list="";

open (FILE,"$file");
close(FILE);
tie (@data,'Tie::File',$file, mode=>O_RDWR) or die "Can't tie to $file
+:$^E\n";

(tied @data)->defer;
foreach (@data)
{
    ($map_dir,$dir,$part_no,$chg_lvl,$int_lock,$t_spec) = split /\s+/;
    print "@list";
    print "$formatted_list";
    print "    $map_dir,$dir,$part_no,$chg_lvl,$int_lock,$t_spec";
}

(tied @data)->flush;

[download]
Thanks

Replies are listed 'Best First'.
Re: Problem with foreach loop
by ikegami (Patriarch) on Jan 25, 2008 at 16:06 UTC

    I can't duplicate your problem.

    You're not changing @data, so (tied @data)->defer; and (tied @data)->flush; are useless. So is Tie::File, for that matter. 

    #!/usr/bin/perl

use strict;
use warnings;

$ENV{HOME} = 'C:\Documents and Settings\kompeS\Desktop\PERL SCRIPTS';
my $file = "$ENV{HOME}/partno_C7_5.03.4_prod";

open(my $fh, '<', $file)
   or die("Unable to open input file \"$file\": $!\n");

while (<$fh>) {
    my ($map_dir,$dir,$part_no,$chg_lvl,$int_lock,$t_spec) = split /\s
++/;
    print "    $map_dir,$dir,$part_no,$chg_lvl,$int_lock,$t_spec";
}

    [download]
[reply]
[d/l]
[select]
Re: Problem with foreach loop
by wfsp (Abbot) on Jan 25, 2008 at 16:11 UTC
    There are a few problems with your code. What was wrong with the advice you've already been given?
[reply]
      Hi all, I made those changes here...actually copied from the old file and made changes to it. I did follow your advice and changed it but didn't upload the file with those changes.:) Ok..I struggled with it and found that if i read the file as an array as shown below in the code I was able to read each line in the file but not with Tie::File. Can some one tell me the reason? 
      
#!/usr/bin/perl 

use strict; 
use warnings; 
use Tie::File; 
use Fcntl; 

#Variable Declaration
my @array; 
my $line=""; 
my @data; 
my $map_dir=""; 
my $dir=""; 
my $part_no=""; 
my $chg_lvl=""; 
my $int_lock=""; 
my $t_spec=""; 
my @list=""; 
my $formatted_list=""; 
my $i;

#Program Main 
if ($#ARGV == -1)
{ 
    print "\n";
    print "Enter a file containing part number, <R> to Quit: ";
    chomp($file_name=<>);
}
else
{
    $file_name=$ARGV[1];    
}


open (FILE,"$file_name"); 
########## 

These two lines are commented out 

################### 

#tie (@data,'Tie::File',$file, mode=>O_RDWR) or die "Can't tie to $fil
+e:$^E\n"; 

#(tied @data)->defer; 

############## 

##I am reading the file as an array here 

################ 
@data=<FILE>; 
foreach (@data) 
{ 

($map_dir,$dir,$part_no,$chg_lvl,$int_lock,$t_spec) = split /\s+/; 
print "@list"; 
print "$formatted_list"; 
print " $map_dir,$dir,$part_no,$chg_lvl,$int_lock,$t_spec"; 

} 

#(tied @data)->flush;

      [download]
      So is there a problem using Tie::File? Thanks
[reply]
[d/l]
        Since you're just beginning with perl, it might be better to forget about Tie::File for now and concentrate on the basics. Don't try to run before you can walk!

        ...roboticus

[reply]

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