1#!/usr/local/bin/perl
2
3use CGI;
4$query = new CGI;
5
6print $query->header;
7print $query->start_html("Save and Restore Example");
8print "<H1>Save and Restore Example</H1>\n";
9
10# Here's where we take action on the previous request
11&save_parameters($query)              if $query->param('action') eq 'SAVE';
12$query = &restore_parameters($query)  if $query->param('action') eq 'RESTORE';
13
14# Here's where we create the form
15print $query->start_multipart_form;
16print "Popup 1: ",$query->popup_menu('popup1',[qw{red green purple magenta orange chartreuse brown}]),"\n";
17print "Popup 2: ",$query->popup_menu('popup2',[qw{lion tiger bear zebra potto wildebeest frog emu gazelle}]),"\n";
18print "<P>";
19$default_name = $query->remote_addr . '.sav';
20print "Save/restore state from file: ",$query->textfield('savefile',$default_name),"\n";
21print "<P>";
22print $query->submit('action','SAVE'),$query->submit('action','RESTORE');
23print "<P>",$query->defaults;
24print $query->endform;
25
26# Here we print out a bit at the end
27print $query->end_html;
28
29sub save_parameters {
30    local($query) = @_;
31    local($filename) = &clean_name($query->param('savefile'));
32    if (open(FILE,">$filename")) {
33	$query->save(FILE);
34	close FILE;
35	print "<STRONG>State has been saved to file $filename</STRONG>\n";
36	print "<P>If you remember this name you can restore the state later.\n";
37    } else {
38	print "<STRONG>Error:</STRONG> couldn't write to file $filename: $!\n";
39    }
40}
41
42sub restore_parameters {
43    local($query) = @_;
44    local($filename) = &clean_name($query->param('savefile'));
45    if (open(FILE,$filename)) {
46	$query = new CGI(FILE);  # Throw out the old query, replace it with a new one
47	close FILE;
48	print "<STRONG>State has been restored from file $filename</STRONG>\n";
49    } else {
50	print "<STRONG>Error:</STRONG> couldn't restore file $filename: $!\n";
51    }
52    return $query;
53}
54
55
56# Very important subroutine -- get rid of all the naughty
57# metacharacters from the file name. If there are, we
58# complain bitterly and die.
59sub clean_name {
60   local($name) = @_;
61   unless ($name=~/^[\w\._\-]+$/) {
62      print "<STRONG>$name has naughty characters.  Only ";
63      print "alphanumerics are allowed.  You can't use absolute names.</STRONG>";
64      die "Attempt to use naughty characters";
65   }
66   return "WORLD_WRITABLE/$name";
67}
68