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Perl

Apache and Perl are a powerful combination in the world of server-side scripting. Perl, with its flexibility and power in text processing and server automation, remains a relevant language today, especially for legacy applications and system scripting. In this guide, we will cover the step-by-step installation of Perl on an Apache web server running AlmaLinux 8, a stable Linux distribution compatible with Red Hat Enterprise Linux (RHEL). This guide is designed for system administrators, web developers, and server service providers who want to maximize the potential of their servers using open-source technologies.

Prerequisite​

  • Full root access
  • Apache/HTTPD installed
  • Basic Linux Command Line
  • Security

Perl Installation​

Before installing, make sure your system is updated to the latest version to avoid potential package conflicts.

dnf update -y

The Apache web server is a key component of this environment. If Apache isn't installed, run the following command:

dnf install httpd -y
systemctl enable --now httpd

Make sure the firewall allows both HTTP and HTTPS traffic:

firewall-cmd --permanent --add-service={http,https}
firewall-cmd --reload

By default, Perl is available in the official AlmaLinux repositories. We just need to run one simple command to install it:

dnf install perl -y

After the installation is complete, verify the Perl version:

perl -v

Here is an example of the output:

This is perl 5, version 26, subversion 3 (v5.26.3) built for x86_64-linux-thread-multi

To allow Apache to execute Perl scripts, we need to enable mod_cgi. On AlmaLinux 8, this module is available within the Apache package:

httpd -M | grep cgi

Example output:

cgid_module (shared)

If the output does not appear, please install the following package:

dnf install httpd-tools -y

Setting Up Directories for Perl Scripts in Apache​

Open the relevant Apache (or virtual host) configuration file. If you don't have a virtual host yet, create one:

nano /etc/httpd/conf.d/focusnic.biz.id.conf

Fill in the following parameters:

/etc/httpd/conf.d/focusnic.biz.id.conf
<VirtualHost *:80>
    ServerAdmin webmaster@focusnic.biz.id
    ServerName focusnic.biz.id
    ServerAlias www.focusnic.biz.id
    DocumentRoot /var/www/focusnic.biz.id/public_html

    <Directory "/var/www/focusnic.biz.id/public_html/perl-app">
        AllowOverride All
        Options +ExecCGI
        AddHandler cgi-script .cgi .pl
        Require all granted
    </Directory>

    ScriptAlias /perl-app/ "/var/www/focusnic.biz.id/public_html/perl-app/"
    ErrorLog /var/log/httpd/focusnic.biz.id-error.log
    CustomLog /var/log/httpd/focusnic.biz.id-access.log combined
</VirtualHost>

Create a directory:

mkdir -p /var/www/focusnic.biz.id/public_html/perl-app/

Next is to create a simple Perl script:

nano /var/www/focusnic.biz.id/public_html/perl-app/hello.pl

Fill in the following script:

/var/www/focusnic.biz.id/public_html/perl-app/hello.pl
#!/usr/bin/perl
print "Content-type: text/html\n\n";
print "<html><head><title>Perl Apache</title></head><body><h1>Perl on Apache!</h1></body></html>";

Adjust the following permissions:

chmod 755 /var/www/focusnic.biz.id/public_html/perl-app/hello.pl

Then, if you use SELinux, please allow the following file to execute:

chcon -t httpd_sys_script_exec_t /var/www/*/public_html/perl-app/ -R

Then restart Apache:

apachectl configtest
systemctl restart httpd

Open in browser http://$DOMAIN_NAME/perl-app/hello.pl

Troubleshooting​

  1. Internal Server Error (500) when opening Perl script

Make sure the file has execute rights:

chmod 755 /var/www/focusnic.biz.id/public_html/perl-app/hello.pl

Make sure the first line of the file is:

#!/usr/bin/perl

Then also check SELinux, please allow execute script:

chcon -t httpd_sys_script_exec_t /var/www/*/public_html/perl-app/ -R

Check Apache error log:

tail -f /var/log/httpd/$NAMA_DOMAIN-error.log
  1. Perl files are not executed, instead they are displayed as text

This is usually caused by mod_cgi not being enabled, or the AddHandler cgi-script .pl parameter not being added. Please enable the .pl handler.

/etc/httpd/conf.d/focusnic.biz.id.conf
AddHandler cgi-script .pl .cgi
Options +ExecCGI
  1. Forbidden or 403 Access Denied

This is usually caused by overly restrictive directory/file permissions and the Require all granted parameter not being set. Please add the following configuration:

/etc/httpd/conf.d/focusnic.biz.id.conf
<Directory "/var/www/focusnic.biz.id/public_html/perl-app">
    Require all granted
</Directory>
  1. perl command not found

Perl is not installed correctly. Please reinstall Perl with the following command:

dnf reinstall perl

Then verify:

which perl

Conclusion​

Perl remains highly relevant for certain server-side applications, and integrating it with Apache provides great flexibility for automation, monitoring, and dynamic web-based data processing.

If you need professional assistance in server installation or optimal cloud hosting configuration, visit Focusnic immediately.

Q: Is Perl installed by default on AlmaLinux 8?
A: Not always. Some minimal versions of AlmaLinux 8 don't include Perl, but you can install it via dnf.

Q: Can I use extensions other than .pl for Perl scripts?
A: Yes. You can use .cgi and configure Apache to recognize it using AddHandler.

Q: Do I have to use mod_cgi?
A: Yes, if you want to execute Perl scripts via Apache. This module is responsible for connecting HTTP requests to the Perl interpreter.

Q: Can I run Perl in specific subdirectories only?
A: Yes. Use the <Directory> configuration to restrict execution to specific folders.

Q: Is it safe to use Perl in a production environment?
A: It is safe, as long as you implement best practices such as: restricting access rights, avoiding unvalidated input, and regularly monitoring logs.

Q: What if I want to develop a Perl-based web application like CGI.pm or Dancer?
A: Install additional modules using CPAN:

dnf install perl-CPAN -y
cpan Dancer