Perl Progress BAR

Shell Programming and Scripting
1

Looking for a solution to why my progress bar not working

My code

print "STARTED:\n ";
my $pdf = CAM::PDF->new('XYZ.pdf') or die $CAM::PDF::errstr;
print STDOUT "Processing File: ";
open (FILE, ">bill_data.txt") || die "Unable to save Bill_data.txt file";
for my $pagenum (1 .. $pdf->numPages) {
...
 DO LOT OF PROCESSING HERE 
...
   }
  print STDOUT "#"; # THIS IS PROGRESS BAR one per page
  &print_it;
}
Close(FILE)
print "\t [ DONE  ]\n"; # Just look nice once done
sub print_it{

print FILE "SOME STUFF ... based on other process..." 
..
Around 20/30 print FILE command
..
}

Now when the program starts I get the message
STARTED:

later it does not show me any progress and then end of program all the #
done etc are printed.

Any thing wrong that I am doing ... I also tried does not work

print STDOUT  "#";
2

Does the bracket I highlighted in red close your for loop too soon?

3

kind of ... below code

i checked with perl -cw ... says ..syntax OK

for my $pagenum (1 .. $pdf->numPages) {
   my $pagetree = $pdf->getPageContentTree($pagenum) or die;
   my @text = $pagetree->traverse('MyRenderer')->getTextBlocks;
   for my $textblock (@text) {
      &create_page($textblock->{str},$textblock->{left},$textblock->{bottom});
   }
  print STDOUT "#";
  &print_it;
}

MyRender is a package defined in same code ...

4

Before your first write to STDOUT and before selecting any other filehandle (if you do 'select' it somewhere) issue the following command:

 
$| = 1;

This sets autoflush to "true" for STDOUT and the output will not be buffered.

This code (stripped down version of yours, without the pdf processing) worked as I think you want yours to work.

#!/usr/bin/perl 
 
$| = 1;
 
print "STARTED:\n";
print STDOUT "Processing file: ";
 
open (FILE, ">bill_data.txt") || die "Can't open bill_data.txt";
for my $pagenum ( 1 .. 10 ) {
 sleep(5);   # for testing only.  replaces other processing and embedded for loop.
 print STDOUT "#";
 &print_it;
}
close (FILE);
print "\t [DONE] \n";
 
sub print_it {
 print FILE "SOME STUFF ... based on other process ...";
 print FILE "SOME STUFF ... based on other process ...";
 print FILE "SOME STUFF ... based on other process ...";
 print FILE "SOME STUFF ... based on other process ...";
 print FILE "SOME STUFF ... based on other process ...";
 print FILE "SOME STUFF ... based on other process ...";
}
5

Yes worked as needed .... Thanks

$|  ----- If set to nonzero, forces a flush of th currently selected stream after every write (Default value = 0)

But usually it was not needed. I could get it working.

Perl is stranger to me ... sometimes :slight_smile: