Site search using Perl + CGI

Tossed license and automake cruft. Just cc -O3 main.c -o matrix now. Don’t need the ceremony.

Runs at 2-3% CPU on OpenBSD (T490). No cause to measure performance more -precisely. No regressions. Fans are quiet.

SITE SEARCH USING PERL + CGI

29 DECEMBER 2025

+
+

Need a way to search site–number of articles are growing.

+ +

Searching site client-side using the RSS feed and JavaScript is not an option– +bloats the feed and breaks the site for Lynx and other text browsers.

+ +

Perl’s great for text processing–especially regex work. Few lines of Perl +could do a regex search and send the result back via CGI. OpenBSD httpd speaks +CGI, Perl and slowcgi are in the base systems. No dependencies. Works on every +conceivable browser.

+ +

Perl: traverse the directory with File::Find recursively. If search text is +found grab the file name, title and up to 50 chars of the first paragraph to +include in the search result.

+ +

find(sub {
+    if (open my $fh, '<', $_) {
+        my $content = do { local $/; <$fh> };
+        close $fh;
+            
+    if ($content =~ /\Q$search_text\E/i) {
+        my ($title) = $content =~ /<title>(.*?)<\/title>/is;
+        $title ||= $File::Find::name;
+        my ($p_content) = $content =~ /<p[^>]*>(.*?)<\/p>/is;
+        my $snippet = $p_content || "";
+        $snippet =~ s/<[^>]*>//g; 
+        $snippet =~ s/\s+/ /g;
+        $snippet = substr($snippet, 0, 50);
+        $snippet .= "..." if length($p_content || "") > 50;
+
+        push @results, { 
+            path    => $File::Find::name, 
+            title   => $title, 
+            snippet => $snippet 
+        };
+    }
+  }
+}, $dir);
+

+ +

Don’t need the Perl CGI module, httpd sets QUERY_STRING for the slowcgi script:

+ +

my %params;
+if ($ENV{QUERY_STRING}) {
+    foreach my $pair (split /&/, $ENV{QUERY_STRING}) {
+        my ($key, $value) = split /=/, $pair;
+        $value =~ tr/+/ /;
+        $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
+        $params{$key} = $value;
+    }
+}
+

+ +

Run the script as www user. Permissions: 554 (read + execute).

+ +

Running in OpenBSD chroot: Check Perl’s dynamic object dependencies:

+ +

$ ldd $(which perl)
+/usr/bin/perl:
+        Start            End              Type  Open Ref GrpRef Name
+        000008797e8e6000 000008797e8eb000 exe   1    0   0      /usr/bin/perl
+        0000087c1ffe5000 0000087c20396000 rlib  0    1   0      /usr/lib/libperl.so.26.0
+        0000087bf4508000 0000087bf4539000 rlib  0    2   0      /usr/lib/libm.so.10.1
+        0000087b9e801000 0000087b9e907000 rlib  0    2   0      /usr/lib/libc.so.102.0
+        0000087bba182000 0000087bba182000 ld.so 0    1   0      /usr/libexec/ld.so
+

+ +

Copy them over to chroot. Now should have /var/www/usr/bin/perl, +/usr/lib/libperl.so.26.0, and so on.

+ +

Troubleshooting: look for issues in logs or try executing the script in chroot:

+ +

$ cat /var/log/messages | grep slowcgi
+# chroot /var/www/ htdocs/path/to/script/script.cgi
+

The last command exposes any missing Perl modules in chroot and where to find +them. Copy them over as well.

+ +

location "/cgi-bin/*" {
+    fastcgi socket "/run/slowcgi.sock"
+}
+

+ +

in httpd.conf routes queries to slowcgi.

+ +

by W. D. Sadeep Madurange