Perl defines three special subroutines that are executed at specific times.
* The BEGIN subroutine, which is called when your program starts.
* The END subroutine, which is called when your program terminates.
* The AUTOLOAD subroutine, which is called when your program can't find a subroutine to executed.
Below is simple perl script which demonstrate the usage of these predefine perl subroutines.
Source: cat predefine_fun.pl
#!/usr/bin/perl
# This will get executed first when your program is started.
BEGIN {
print "Starting the loop ... \n";
print " ------------------------- \n";
}
# This will get executed when your program terminates.
END {
print " ------------------------- \n";
print "End of this perl script \n";
print "Perl is awesome :) \n";
}
# This is called whenever the Perl try to call a subroutine that does not exist.
AUTOLOAD {
print "Oosp, we are not able to find the required function : $AUTOLOAD \n";
print "This is bad \n"
}
for ($i = 0; $i < 5 ;$i++ ) {
print "$i \n";
}
&doesnotexists;
#!/usr/bin/perl
# This will get executed first when your program is started.
BEGIN {
print "Starting the loop ... \n";
print " ------------------------- \n";
}
# This will get executed when your program terminates.
END {
print " ------------------------- \n";
print "End of this perl script \n";
print "Perl is awesome :) \n";
}
# This is called whenever the Perl try to call a subroutine that does not exist.
AUTOLOAD {
print "Oosp, we are not able to find the required function : $AUTOLOAD \n";
print "This is bad \n"
}
for ($i = 0; $i < 5 ;$i++ ) {
print "$i \n";
}
&doesnotexists;
source:http://linuxpoison.blogspot.com/2012/10/135781677518212.html