Find out Apache Version

In order to find out apache version, login to your server. Once logged in type the following command to print the version of httpd :
# httpd -v

Sample output:

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

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.