Note: these steps are obsolete. In the comments, McDutchy points out a much easier way. This is much less work and also doesn't require any packages to be reinstalled.
Slackware 10.2 doesn't include mod_perl. To install this package while staying as close to the original Slackware installation, we're going to compile mod_perl using the patched Apache that's particular to Slackware.
First we download Slackware's Apache source and mod_perl. Download all the Slackware files from your favorite mirror. Also download mod_perl and put it in the same directory.
Edit the Slackware build script apache.SlackBuild. Add the following line after line 26:
tar xvzf $CWD/mod_perl-1.0-current.tar.gz
Before the comment line that says "# build apache", insert the following lines:
# build mod_perl cd $TMP/mod_perl-1.29 perl Makefile.PL \ APACHE_SRC=../apache_1.3.33/src \ NO_HTTPD=1 \ USE_APACI=1 \ PREP_HTTPD=1 \ EVERYTHING=1 \ make make install
Finally add the following line after the ./configure options of Apache:
--activate-module=src/modules/perl/libperl.a \
As root, execute the Slackware build script. When it's done, install the resulting package:
# sh ./apache.SlackBuild # installpkg /tmp/apache-1.3.33-i486-1.tgz
If any question comes up, accept the default. After installation, you may also need to add the following lines to the file /etc/apache/httpd.conf:
LoadModule perl_module libexec/apache/libperl.so AddModule mod_perl.c