Basic. Simple example using CGI module:
#!/usr/bin/perl
use CGI qw(:standard);
print "Content-type: text/html\n\n";
print "<html>\n";
$name = param("name");
print "<body>$name</body>\n";
print "</html>";
Showing posts with label Perl. Show all posts
Showing posts with label Perl. Show all posts
Thursday, February 21, 2008
Wednesday, September 19, 2007
Using CPAN Modules
FAQ: Here are some of my frequently used commands for CPAN
# Interactive mode
% sudo perl -MCPAN -e shell
# Installing a module
% sudo perl -MCPAN -e "install Some::Module"
# List of versions of installed and available modules
% sudo perl -MCPAN -e 'CPAN::Shell->r'
# Upgrade all modules
% sudo perl -MCPAN -e \
'CPAN::Shell->install(CPAN::Shell->r)'
Configuration: If you are getting this error
CPAN.pm needs either the external programs
tar, gzip and bzip2 installed. Can’t continue.
Try this:shell> sudo perl -MCPAN -eshell
cpan> o conf tar /bin/tar
cpan> o conf bzip2 /bin/bzip2
cpan> o conf gzip /bin/gzip
cpan> o conf commit
Thursday, September 13, 2007
Parsing XML using XML::Simple
Installing XML::Simple:
shell> perl -MCPAN -e shell
cpan> install XML::Simple
Reading XML: You can use XMLin and XMLout to read and write XML file or string.
my $ref = XMLin('/dir/to/file.xml'); # it takes file
my $ref2 = XMLin('<xml> .... '); # or string
Example of reading a podcast feed:
#!/usr/bin/perl -w
use strict;
use warnings;
use LWP::Simple;
use XML::Simple;
use Data::Dumper;
my $url = 'http://url/feed.xml';
my $content = get $url;
die "Couldn\'t get $url" unless $content;
my $ref = XMLin($content);
my @items = @{$ref->{'channel'}->{'item'}};
# grabbing link
for my $i ( 0 .. $#items ) {
print ${$items[$i]}{'link'} . "\n";
}
Wednesday, August 22, 2007
Perl LWP
Installing: LWP
username@ubuntu:~$ sudo perl \
-MCPAN -e 'install Bundle::LWP'
Once you install Bundle::LWP, you can test it out the code by
#!/usr/bin/perl -w
use strict;
use warnings;
use LWP::Simple;
my $url = 'http://www.google.com/';
my $content = get $url;
die "Couldn't get $url" unless defined $content;
print $content;
Update: Probably you might want to do this first
sudo perl -MCPAN -e shell
cpan> install Bundle::CPAN
cpan> reload cpan
Wednesday, April 18, 2007
Perl data structures
Arrays of Arrays.
#!/usr/bin/perl -w
use strict;
my @AoA = (
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
);
# accessing arrays of arrays using index
for my $i ( 0 .. $#AoA ) {
for my $j ( 0 .. $#{$AoA[$i]} ) {
print $AoA[$i][$j] . "\t";
}
print "\n";
}
# accessing arrays of arrays
for my $row ( @AoA ) {
for my $col ( @{$row} ) {
print $col . "\t";
}
print "\n";
}
Arrays of Hashes.
#!/usr/bin/perl -w
use strict;
my @AoH;
push @AoH, { a => 1, b => 2 };
push @AoH, { c => 3, d => 4 };
for my $i ( 0 .. $#AoH ) {
for my $k ( keys %{$AoH[$i]} ) {
print $k . ":" . ${$AoH[$i]}{$k} . " ";
}
print "\n";
}
Hashes of Hashes.
#!/usr/bin/perl -w
use strict;
my %HoH;
$HoH{"keyA"} = { a => 1, b => 2 };
$HoH{"keyB"} = { c => 3, d => 4 };
for my $kA ( keys %HoH ) {
print $kA . ":\n";
for my $kB ( keys %{$HoH{$kA}} ) {
print $kB . ":" . $HoH{$kA}{$kB} . " ";
}
print "\n";
}
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