Perl Form Parse

# perl0002.lib
# Written:  1999-06-03  James Alarie
#   Base from "Perl and CGI for the world wide web" by Elizabeth Castro.
#   I changed it to add localization of variables,
#     retrieve QUERY_STRING information for POST,
#     output into @formdata as well as %formdata,
#     return values for fields named by $ENV or date_time variables,
#     not separate multi-values of matching-name fields,
#     break on either "&" or ";".
#
# FormParse Subroutine:
#   call with:
#     $_[0]: (add values as needed)
#       0  no expansion
#       1  expand %ENV variables
#       2  expand %date_time variables
#   returns:
#     %formdata, @formdata

sub form_parse{
  local($buffer, @cookies, $countw, $countg);
  local($pair, $key, $value, @pairs);
  @formdata=(); %formdata=(); @pairs=();

  if ($ENV{'REQUEST_METHOD'} eq 'GET') {            # get from URL
    @pairs = split(/[&;]/, $ENV{'QUERY_STRING'});   # split on "&" and ";"
  } elsif ($ENV{'REQUEST_METHOD'} eq 'POST') {
    read (STDIN, $buffer, $ENV{'CONTENT_LENGTH'});  # read STDIN
    if ($ENV{'QUERY_STRING'} ne "") {               # something on URL
      $buffer = $ENV{'QUERY_STRING'}."&".$buffer;   # ...use as prefix
    }
    @pairs = split(/[&;]/, $buffer);                # split on "&" and ";"
  } else {
    print "Content-type: text/html\n\n";            # error!
    print "<p>You must use Post or Get</p>";
  }

  foreach $pair (@pairs) {                          # one at a time
    ($key, $value) = split (/=/, $pair);            # split on "="
    $key =~ tr/+/ /;                                # trans "+" to space
    $key =~ s/%([a-fA-F0-9]{2})/pack("C", hex($1))/eg;  # Hex to ASCII

    $value =~ tr/+/ /;
    $value =~ s/%([a-fA-F0-9]{2})/pack("C", hex($1))/eg;
    $value =~ s/<!--(.|\n)*-->//g;                  # no server side includes

    $exp = $_[0];
    $exp2 = $exp % 2;                               # rightmost bit
    if ($value eq '') {
      if ($exp2 == 1) { $value = $ENV{$key}; }
    }
    $exp = int($exp / 2);                           # strip rightmost bit
    $exp2 = $exp % 2;
    if ($value eq '') {
      if ($exp2 == 1) { $value = $date_time{$key}; }
    }

    push(@formdata, $key, $value);
    if ($formdata{$key}) {                         # already known key
      $formdata{$key} .= "$value";                 # add another value
    } else {
      $formdata{$key} = $value;
    }
  }

}


#***** Accessed correctly:
1;