Found very good link about Memory Management in PERL: http://www.perl.com/pub/2002/08/07/proxyobject.html
if(tell(filehandle) != -1)
{
//file is already opened ! [as tell returns -1]
}
very useful:
awk -v FS='|' -v OFS='|' '{$3=$3"|"4} 1' 1.txt
Input:
1|2|3|5
1|2|3|5
1|2|3|5
1|2|3|5
Output:
1|2|3|4|5
1|2|3|4|5
1|2|3|4|5
1|2|3|4|5
Simple & useful: [Many times i forfot this trick]
[mandy ~]$ echo $v1
75
[mandy ~]$ awk -F "|" ' { print $'"$v1"' } ' file_name
mandar
mpande
mp
[mandy ~]$ sed 's/'"$old_val"'/'"$new_val"'/g' file_name
Found a very good article/link in XML Parsing: Need to check this PullXML Parser thing is available with Perl/Python ? This kind of parsing seems to be really faster, efficient than SAX [Off course faster/better than DOM :)]. XML Pull Parser . http://www.bearcave.com/software/java/xml/xmlpull.html
Simple but very useful:
#-------------------------------
# Validation for 5GB free space.
#-------------------------------
#AIX OS
if [ `uname` = "AIX" ]
then
if [ `df -g $op_path | awk ' { print $2 } ' | tail -1` -lt 5 ]
then
echo "Minimum of 5GB of free space should be presnt at $op_path to run the script"
exit
fi
fi
#HP-UX
if [ `uname` = "HP-UX" ]
then
val=`bdf $op_path | awk ' { print $4 } ' | tail -1`
val_gb1=`echo "scale=2; $val/1024" | bc`
val_gb=`echo "scale=2; $val_gb1/1024" | bc`
#if [ $val_gb \< 5 ]
if [ $val_gb -lt 5 ]
then
echo "Minimum of 5GB of free space should be presnt at $op_path to run the script"
exit
fi
fi
#SunOS
if [ `uname` = "SunOS" ]
then
val=`df -k $op_path | awk ' { print $4 } ' | tail -1`
val_gb1=`echo "scale=2; $val/1024" | bc`
val_gb=`echo "scale=2; $val_gb1/1024" | bc`
#if [ $val_gb \< 5 ]
if [ $val_gb -lt 5 ]
then
echo "Minimum of 5GB of free space should be presnt at $op_path to run the script"
exit
fi
fi
#Linux
if [ `uname` = "Linux" ]
then
val=`df -k $op_path | awk ' { print $4 } ' | tail -1`
val_gb1=`echo "scale=2; $val/1024" | bc`
val_gb=`echo "scale=2; $val_gb1/1024" | bc`
if [ $val_gb \< 5 ]
then
echo "Minimum of 5GB of free space should be presnt at $op_path to run the script"
exit
fi
fi
Base Class:
-----------
#!/usr/bin/perl
use strict;
use Data::Dumper;
#write package name:
package Person;
#write constructor
sub new
{
#declare => hash & bless it and return it.
my($class)=shift;
my($self)={
_name=>shift,
_sname=>shift,
};
bless $self, $class;
return $self;
}
1;
Derived class:
--------------
#!/usr/bin/perl
#define package:
package Employee;
use strict;
use Data::Dumper;
#use parent class
use Person;
#Define ISA
our @ISA = qw(Person);
#Define constructor with child and parent both:
sub new
{
my($class)=@_;
my($self)=$class->SUPER::new($_[1],$_[2]);
$self->{_id} = $_[3];
$self->{_sal} = $_[4];
return ($self);
}
1;
Program:
--------
use strict;
use Data::Dumper;
use Person;
use Employee;
sub main
{
my($obj)=Employee->new("mandar","pande","111515","1");
print "$obj->{_name}\n";
print "$obj->{_sname}\n";
print "$obj->{_id}\n";
print "$obj->{_sal}\n";
}
main();