perl recursive function issue

pritish.sas · June 15, 2010, 11:46am

I am facing some problem in perl recurssive function function

my @array_parent = (Some inegers);
my $outputfile = 'output.txt';
my $master_file = 'master.txt';
open (MASTER,"$>>master.txt");
foreach my $child (@array_parent){
        my $line = `grep "$child" "$outputfile"`;
        chomp($line);
        chomp($child);
        my @match = grep (/$child/i, @array_parent_level1);
        if ($child == 22105201 ){
              Lookup($line,*MASTER,$outputfile);
        }
}
close(OUT);
close(MASTER);
sub Lookup {
        my ($line,$MASTER,$outputfile)= @_;
        my ($parent,$len);
        open (OUT,"<$outputfile") or die "Can't OPen File $outputfile";
        chomp($line);
        $parent = (split /,/,$line)[8];
        print "$parent\n";
        $len = length($parent);
        print "$len\n";
        if ($len == 0) {
                print "Please goto foreach\n";
                return 1;
        }
        else{
                while(<OUT>) {
                        chomp;
                        my $field = (split/,/)[6];
                        if ($field == $parent){
                                my $line = $_;
                                print "ok\n";
                                #print "$parent|$field|$line\n";
                                sleep(2);
                                Lookup($line,*MASTER,$outputfile);
                        }
                }
         }
}

After 3 time of Lookup function call, i am getting 0 is $len variable, it should be satisfied the condition and return 1 should execute, but function is calling infinite time.

Please do the needful expert

zedex · June 15, 2010, 2:05pm

Hi can you explain in short what you are trying to do & sample input & output ??
btw you are calling a the same subroutine from same subroutine are you sure that is right ??

pritish.sas:

I am facing some problem in perl recurssive function function

my @array_parent = (Some inegers);
my $outputfile = 'output.txt';
my $master_file = 'master.txt';
open (MASTER,"$>>master.txt"); # where exactly you are using this file handler ?? you opened the file in append mode but never actually writing on file handler 
foreach my $child (@array_parent){
   chomp ( my $line = `grep "$child" "$outputfile"` ) ;
   # chomp($line);
   chomp($child);
   my @match = grep (/$child/i, @array_parent_level1); # where is this array defined ??
   if ($child == 22105201 ){
   Lookup($line,*MASTER,$outputfile);
   }
}
close(OUT);
close(MASTER);

sub Lookup {
   my ($line,$MASTER,$outputfile)= @_;
   my ($parent,$len);
   open (OUT,"<$outputfile") or die "Can't OPen File $outputfile"; # Read the file in an array before sending it to function and pass the reference of array here .. so even if you call this function 100 times or 1 time you will do file I/O only once 
  
   chomp($line); # you can avoid this you are already chomping the var before sending to subroutine 
   $parent = (split /,/,$line)[8];
   print "$parent\n";
   $len = length($parent);
   print "$len\n";
   # if ( $parent )  will be sufficient to check if its empty or not no need to check its length.
   if ($len == 0) {
   print "Please goto foreach\n";
   return 1;
   }
   else{
   while(<OUT>) {
   chomp;
   my $field = (split/,/)[6];
   # if $field & $parent are string then user "eq" for comparison 
   if ($field == $parent){
   my $line = $_;
   print "ok\n";
   #print "$parent|$field|$line\n";
   sleep(2);
   Lookup($line,*MASTER,$outputfile); # once code is here then this will be infinite loop :) 
   }
   }
   }
}

After 3 time of Lookup function call, i am getting 0 is $len variable, it should be satisfied the condition and return 1 should execute, but function is calling infinite time.

Please do the needful expert