I have a rented dedicated LAMP solution stack server. I need to know what version of Apache I am running. How do I find out my Apache server version? How do I find out what modules loaded using command line option on Linux or Unix like operating systems?

The acronym LAMP refers the components of the solution stack composed entirely of free and open-source software as follows:

1. L for Linux operating systems
2. A for Apache http web server
3. M for MySQL or MariaDB database management server
4. P for PHP, Perl, or Python scripting languages

Task: Show Apache httpd web server version command

httpd is the Apache HyperText Transfer Protocol (HTTP) server program. In order to find out apache version login to server using ssh or console. Once logged in type the following command to print the version of httpd, and then exit:
# httpd -v
Sample output:

Server version: Apache/2.2.3
Server built:   Oct 28 2008 07:22:45

Task: Output a list of modules compiled into the server:

# httpd -l
This will not list dynamically loaded modules included using the LoadModule directive. To dump a list of loaded Static and Shared Modules:
# httpd -M
Sample output:

Loaded Modules:
 core_module (static)
 mpm_prefork_module (static)
 http_module (static)
 so_module (static)
 auth_basic_module (shared)
 auth_digest_module (shared)
 authn_file_module (shared)
 authn_alias_module (shared)
 authn_anon_module (shared)
 authn_dbm_module (shared)
 authn_default_module (shared)
 authz_host_module (shared)
 authz_user_module (shared)
 authz_owner_module (shared)
 authz_groupfile_module (shared)
 authz_dbm_module (shared)
 authz_default_module (shared)
 ldap_module (shared)
 authnz_ldap_module (shared)
 include_module (shared)
 log_config_module (shared)
 logio_module (shared)
 env_module (shared)
 ext_filter_module (shared)
 mime_magic_module (shared)
 expires_module (shared)
 deflate_module (shared)
 headers_module (shared)
 usertrack_module (shared)
 setenvif_module (shared)
 mime_module (shared)
 dav_module (shared)
 status_module (shared)
 autoindex_module (shared)
 info_module (shared)
 dav_fs_module (shared)
 vhost_alias_module (shared)
 negotiation_module (shared)
 dir_module (shared)
 actions_module (shared)
 speling_module (shared)
 userdir_module (shared)
 alias_module (shared)
 rewrite_module (shared)
 proxy_module (shared)
 proxy_balancer_module (shared)
 proxy_ftp_module (shared)
 proxy_http_module (shared)
 proxy_connect_module (shared)
 cache_module (shared)
 suexec_module (shared)
 disk_cache_module (shared)
 file_cache_module (shared)
 mem_cache_module (shared)
 cgi_module (shared)
 version_module (shared)
 chroot_module (shared)
 perl_module (shared)
 php5_module (shared)
 proxy_ajp_module (shared)
 python_module (shared)
Syntax OK

Print the version and build parameters of httpd, and then exit

Type the command:
# httpd -V
Sample output:

Server version: Apache/2.2.3
Server built:   Oct 28 2008 07:22:45
Server's Module Magic Number: 20051115:3
Server loaded:  APR 1.2.7, APR-Util 1.2.7
Compiled using: APR 1.2.7, APR-Util 1.2.7
Architecture:   64-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_PIDLOG="logs/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="logs/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

To view other configuration settings open httpd.conf file (usually located in /etc/httpd directory). Red hat, CentOS and Fedora stores httpd at the following location:
# vi /etc/httpd/conf/httpd.conf
Debian and Ubuntu stores httpd.conf in apache2.conf file at the following location:
# vi /etc/apache2/apache2.conf
FreeBSD stores apache2.2 configuration at the following location:
# vi /usr/local/etc/apache22/httpd.conf
If you made any changes to httpd.conf, check httpd syntax for error using the -t option:
# httpd -t
If there are no errors, simply restart Apache web server.