In function-oriented mode, the functions of CGI.pm are called directly. The Perl CGI module is loaded with use() function; the modifier :standard imports the standard set of funtions into your program.
header(), start_html(), h1(), etc. are all functions of the CGI module that return HTML markup. Note that the arguments passed to the functions may be tags (header()), attributes (-bgcolor=>'white'), or content (h1('Starting CGI scripting')).
#!/usr/local/bin/perl -w
use CGI ':standard';
print header(),
start_html(-title=>'hello',
-bgcolor=>'white'),
h1('Starting CGI scripting'),
p('All the things you need for scripting');
print ol(
li('patience'),
li('endurance')
);
print hr();
print h3('Forms');
print start_form(-method=>'post',
-action=>'http://people.cs.uchicago.edu/~wfreis/cgi-bin/reflector.pl'),
textfield(-name=>'textfield1', -size=>'50', -maxlength=>'50'),
br,
submit('submit', 'Submit'),
endform();
print end_html();