The views expressed on this blog are my own and do not necessarily reflect the views of Oracle.

Thursday, June 4, 2009

Traversing directory structure in perl

Today I started learning a bit of perl and created a small program to search for a particular string in all the xml files in the current directory as well as any sub-directory and printing the count of occurence of string.

Here is the code:
#!/usr/bin/perl --  
use strict;
use warnings;
use diagnostics;
use Fatal qw/:void open close/;
#first find the .xml files in the directory recursively and store in a temp list
  $f=`find . -name "*.xml" > /tmp/fileList`; 
 open TEMPFILE, "/tmp/fileList" ;
 $subflowCount = 0; 
 # traverse throygh each xml file 
 while( ){ 
 $file = $_;  
 #if yes then look for subflow tag           
    $result=`grep -i  "" $file`;   if ( $result=~m//){
print $file."\n";
 $subflowCount = $subflowCount + 1; 
 print "Total subflows are:";
 print $subflowCount; 

I have commented the code to understand what it is doing.
To run go to linux box:
do: chmod 777 
do ./


chorny said...

It would be easier and more readable to use File::Find module.

P.S. Add "use strict;use warnings;use diagnostics;use Fatal qw/:void open close/;" at start of your code, after #!. Later you can drop last two.

Unknown said...

Thankx and i added your suggestions.

Unknown said...

Hi @Vik good shot, but I think you are kidding yourself if you think this is perl;-)

Suggest you try to do the same thing, but without using any backticks or system calls. Like many tasks, this is possible in pure Perl - no O/S calls at all. (Which btw makes it a great language for cross-platform database scripts since perl is installed by default with Oracle -- as long as you steer clear of the O/S calls!)

I spend more time forgetting Perl than learning it, so I always have my trusty O'Reilly 'animal books' near to hand. The Perl Cookbook is always the first I reach for, and it has all the recipes you need for this. If you don't already have a copy, I couldn't recommend it more highly.

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