What is this piesce of code doing ?

[Nilay Puri]

Hi All,

I have samll piece of code in which a subroutine is calles in unusual way .

#/usr/local/bin/perl

BEGIN {
$ENV{ORACLE_HOME} = '/home/oracle/app/oracle/product/8.0.5';
}

my $VENTURA_BASEDIR = '/home/www/highered/mdb';
my $FTP_PATH = 'ftp://ftp.prenhall.com/incoming/booksellers';
use AWL_Ventura_Document;
use DBI;
use Carp;
use strict;

if (scalar(@ARGV) != 1) {
print "Usage: cpm_feed.pl [filename]\n";
exit(0);
}

my $DATALOAD_FILE_NAME = $ARGV[0];
my ($USERNAME, $PASSWORD, $SID);
$USERNAME = 'pinfo';
$PASSWORD = 'pinfo';
$SID = 'hemdaprd';
# Turn I/O buffering off.
$| = 1;

exit &main; # I have never come across such sub routine call ? Is it
combining 2 call ? Namely - &main and then exit with the return value of
main routine ?

# after this I have the definition of the sub routine main
sub main {
----------
-----------
}

Regards,
Nilay

[Andrew Gaffney]

Nilay Puri, Noida wrote:

> Hi All,
>
> I have samll piece of code in which a subroutine is calles in unusual way .
>
> #/usr/local/bin/perl
>
> BEGIN {
> $ENV{ORACLE_HOME} = '/home/oracle/app/oracle/product/8.0.5';
> }
>
> my $VENTURA_BASEDIR = '/home/www/highered/mdb';
> my $FTP_PATH = 'ftp://ftp.prenhall.com/incoming/booksellers';
> use AWL_Ventura_Document;
> use DBI;
> use Carp;
> use strict;
>
> if (scalar(@ARGV) != 1) {
> print "Usage: cpm_feed.pl [filename]\n";
> exit(0);
> }
>
> my $DATALOAD_FILE_NAME = $ARGV[0];
> my ($USERNAME, $PASSWORD, $SID);
> $USERNAME = 'pinfo';
> $PASSWORD = 'pinfo';
> $SID = 'hemdaprd';
> # Turn I/O buffering off.
> $| = 1;
>
> exit &main; # I have never come across such sub routine call ? Is it
> combining 2 call ? Namely - &main and then exit with the return value of
> main routine ?

That's certaintly what it looks like it is doing. This is Perl. TMTOWTDI.

> # after this I have the definition of the sub routine main
> sub main {
> ----------
> -----------
> }
>
> Regards,
> Nilay
>

--
Andrew Gaffney
Network Administrator
Skyline Aeronautics, LLC.
636-357-1548

[Eternius]

Nilay Puri wrote:

> Hi All,
>
> I have samll piece of code in which a subroutine is calles in unusual way .
>
> #/usr/local/bin/perl
>
> BEGIN {
> $ENV{ORACLE_HOME} = '/home/oracle/app/oracle/product/8.0.5';
> }
>
> my $VENTURA_BASEDIR = '/home/www/highered/mdb';
> my $FTP_PATH = 'ftp://ftp.prenhall.com/incoming/booksellers';
> use AWL_Ventura_Document;
> use DBI;
> use Carp;
> use strict;
>
> if (scalar(@ARGV) != 1) {
> print "Usage: cpm_feed.pl [filename]\n";
> exit(0);
> }
>
> my $DATALOAD_FILE_NAME = $ARGV[0];
> my ($USERNAME, $PASSWORD, $SID);
> $USERNAME = 'pinfo';
> $PASSWORD = 'pinfo';
> $SID = 'hemdaprd';
> # Turn I/O buffering off.
> $| = 1;
>
> exit &main; # I have never come across such sub routine call ? Is it
> combining 2 call ? Namely - &main and then exit with the return value of
> main routine ?
>
> # after this I have the definition of the sub routine main
> sub main {
> ----------
> -----------
> }
>
> Regards,
> Nilay

I suggest writing a simple one:
#simple.pl
#!/usr/bin/perl -w
sub main{
return 1;
}
exit &main;
#end

and then try it:
xg04123@oppo:~> ./simple.pl && echo error
error

cheers

Eternius