![[APACHE DOCUMENTATION]](images/sub.gif) 
 New features with this release, as extensions of the Apache functionality. Because the core code has changed so significantly, there are certain liberties that earlier versions of Apache (and the NCSA daemon) took that recent Apache versions are pickier about - please check the compatibility notes if you have any problems.
If you're upgrading from Apache 1.2, you may wish to read the upgrade notes.
Enhancements: Core | Performance | Configuration | Modules | API | Misc
Configuration have been replaced with "AddModule"
    with a slightly different syntax.  For module authors there are
    some changes designed to make it easier for users to add their
    module.
ProxyReceiveBufferSize directive gives
     mod_proxy's outgoing connections larger network
     buffers, for increased throughput.
 writev (where
     available) to issue multiple writes with a single system call.
     They also avoid copying memory into buffers as much as
     possible.  The result is less CPU time spent on transferring
     large files.
 mmap, which
     means bytes are only copied from the disk buffer to the
     network buffer directly by the kernel.  The program never
     copies bytes around, which reduces CPU time.  (Only where
     available/tested.)
 mod_log_config can
     be compile-time configured to buffer writes.
 strncpy() with
     ap_cpystrn(), a routine which doesn't have to
     zero-fill the entire result.  This has dramatic effects on
     mod_include speed.
 See the new performance documentation for more information.
configure script and a corresponding top-level
    Makefile.tmpl file. The goal is to provide a GNU
    Autoconf-style frontend which is capable to both drive the old
    src/Configure stuff in batch and additionally
    installs the package with a GNU-conforming directory layout.  Any
    options from the old configuration scheme are available plus a lot
    of new options for flexibly customizing Apache.README.configure and
    INSTALL for more information.
apxs was created which provides off-source building,
    installing and activating of those DSO-based modules. It
    completely hides the platform-dependent DSO-build commands from
    the user and provides an easy way to build modules outside the
    Apache source tree. To achieve this APACI installs the Apache C
    header files together with the apxs tool.
 
/usr/local/apache//usr/local/etc/httpd/ to
    /usr/local/apache/.  This change covers only the
    default setting (and the documentation); it is of course possible
    to override it using the  -d
    ServerRoot and -f httpd.conf switches when
    starting apache.
NameVirtualHost
    directive is used to list IP address:port pairs on which
    HTTP/1.1-style virtual hosting occurs.  This is vhosting based on
    the Host: header from the client.  Previously this
    address was implicitly the same as the "main address" of the
    machine, and this caused no end of problems for users, and was not
    powerful enough.  Please see the Apache Virtual Host documentation for
    further details on configuration.
Include directive
Include
    directive includes other config files immediately at that point in
    parsing.
-S command line option
    it will dump out information regarding how it parsed the
    VirtualHost sections.  This is useful for folks
    trying to debug their virtual host configuration.
SetEnvIf and
    
    SetEnvIfNoCase.  These allow you to set
    environment variables for server and CGI use based upon attributes
    of the request.
mod_mime_magic has been
    added. It uses "magic numbers" and other hints from a file's
    contents to figure out what the contents are. It then uses this
    information to set the file's media type, if it cannot be
    determined by the file's extension.
UNIQUE_ID.
ProxyVia
    directive allows switching "Via:" support off or on, or
    suppressing outgoing "Via:" header lines altogether for privacy
    reasons.
NoProxy and ProxyDomain
    directives added to proxy, useful for intranets.
    ProxyPassReverse directive.  It lets Apache adjust the
    URL in the Location header on HTTP redirect
    responses. 
mod_include string comparisonsmod_dir module has
        been split in two, with mod_dir handling directory index
        files, and mod_autoindex
        creating directory listings.  Thus allowing folks to remove the
        indexing function from critical servers.
    SuppressColumnSorting IndexOptions
        keyword.
    SuppressHTMLPreamble can be used if
        your README.html file includes its own HTML header.
    IndexOptions directive now allows
        the use of incremental prefixes (+/- to add/remove the respective
        keyword feature, as was already possible for the
        Options directive) to its
        keyword arguments. Multiple IndexOptions directives applying
        to the same directory will now be merged.
    IconHeight and
	IconWidth
        let you set height and width attributes to the
        <IMG> tag in directory listings.
    NameWidth keyword to the
        IndexOptions
	directive lets you set the number of columns for
	"fancy"
	directory listings. If set to an '*' asterisk, the name width
	will be adjusted automatically.
    Alias and Redirect
AliasMatch,
    ScriptAliasMatch, and
    RedirectMatch
    directives allow for the use of regular expression matching.
    Additionally, new
    <DirectoryMatch>,
    <LocationMatch>,
    and
    <FilesMatch>
    sections provide a new syntax for regular expression sectioning.
AddModuleInfo
    directive added to mod_info
TransferLog disables 
    logging
TransferLog directive is given then no log is
    written.  This supports co-existence with other logging modules.
LogFormat
    directive has been enhanced to allow you to give nicknames to
    specific logging formats.  You can then use these nicknames in
    other LogFormat and CustomLog directives, rather than having to
    spell out the complete log format string each time.
RewriteMap
    directive
RewriteMap directive of
    mod_rewrite.  They provide two new features: First, you now can
    randomly choose a sub-value from a value which was looked-up in a
    rewriting map (which is useful when choosing between backend
    servers in a Reverse Proxy situation). Second, you now can
    translate URL parts to fixed (upper or lower) case (which is
    useful when doing mass virtual hosting by the help of
    mod_rewrite).
For all those module writers and code hackers:
child_init
child_exit
child_init and
    child_exit functions are passed a pool whose lifetime is
    the same as the lifetime of the child (modulo completely fatal
    events in which apache has no hope of recovering).  In contrast,
    the module init function is passed a pool whose lifetime
    ends when the parent exits or restarts.
child_terminate
register_other_child
http_main.h.  This is used in the parent to register
    a child for monitoring.  The parent will report status to a supplied
    callback function.  This allows modules to create their own children
    which are monitored along with the httpd children.
piped_log
http_log.h.  This API provides the common code for
    implementing piped logs.  In particular it implements a reliable piped
    log on architectures supporting it (i.e., Unix at the moment).
set_last_modified split into three
set_last_modified performed multiple
    jobs including the setting of the Last-Modified header, the
    ETag header, and processing conditional requests (such as
    IMS).  These functions have been split into three functions:
    set_last_modified, set_etag, and
    meets_conditions.  The field mtime has been
    added to request_rec to facilitate
    meets_conditions.
ap_log_error
ap_log_error.
    This is still a work in progress.
set_file_slot for config parsing
set_file_slot routine provides a standard routine that
    prepends ServerRoot to non-absolute paths.
post_read_request module API
psocket, and popendir
psocket and pclosesocket functions allow
    for race-condition free socket creation with resource tracking.
    Similarly popendir and pclosedir protect
    directory reading.
is_initial_req
kill_only_once
ap_spawn_child functions which prevents Apache
    from aggressively trying to kill off the child.
alloc debugging code
ALLOC_DEBUG provides a rudimentary memory
    debugger which can be used on live servers with low impact --
    it sets all allocated and freed memory bytes to 0xa5.  Defining
    ALLOC_USE_MALLOC will cause the alloc code to use
    malloc() and free() for each object.  This
    is far more expensive and should only be used for testing with tools
    such as Electric Fence and Purify.  See main/alloc.c
    for more details.
ap_cpystrn
strncpy "lookalike", with slightly different
    semantics is much faster than strncpy because it
    doesn't have to zero-fill the entire buffer.
table_addn, table_setn,
    table_mergen
pstrdup
    on their arguments.  This provides for big speedups.  There is
    also some debugging support to ensure code uses them properly.
    See src/CHANGES for more information.
construct_url
server_rec * to taking a request_rec *.
get_server_name, get_server_port
ap_bspawn_child and
    ap_call_exec
child_info * to spawn function 
    (as passed to ap_bspawn_child) and to 
    ap_call_exec to allow children to work correctly on Win32.
    We also cleaned up the nomenclature a bit, replacing
    spawn_child_err with simply
    ap_spawn_child and spawn_child_err_buff
    with simply ap_bspawn_child.
ap_add_version_component()
Server:
    header line. Previous 1.3beta versions had used a
    SERVER_SUBVERSION compile-time #define
    to perform this function. Whether the tokens are actually displayed
    is controlled by the new ServerTokens directive.
AccessFileName
    Enhancement
AccessFileName directive can now take more than
    one filename. This lets sites serving pages from network file
    systems and more than one Apache web server, configure access
    based on the server through which shared pages are being served.
HostNameLookups now defaults to "Off"
HostNameLookups
    directive now defaults to "Off". This means that, unless explicitly
    turned on, the server will not resolve IP addresses into names. This
    was done to spare the Internet from unnecessary DNS traffic.
HostnameLookups
    directive now supports double-reverse DNS.  (Known as
    PARANOID in the terminology of tcp_wrappers.)  An IP
    address passes a double-reverse DNS test if the forward map of the
    reverse map includes the original IP.  Regardless of the
    HostnameLookups setting, mod_access access lists using DNS
    names require all names to pass a double-reverse
    DNS test.  (Prior versions of Apache required a compile-time
    switch to enable double-reverse DNS.)
timefmt string used by mod_include has been
    modified to display the year using four digits rather than the
    two-digit format used previously.  The mod_autoindex
    module has also been modified to display years using four digits
    in FancyIndexed directory listings.
htdigest), and these other applications would fail to
    build because the routines were built only into the server.  These
    routines are now being migrated to a separate subdirectory and
    library so they can be used by other applications than just the
    server.  See the src/ap/ subdirectory.
    ServerSignature directive
    UseCanonicalName directive
UseCanonicalName
    off Apache will use the hostname and port supplied by the
    client, if available.
SERVER_VERSION definition abstracted, and server
    build date added 
#defined value for
    SERVER_VERSION.  In order to keep this value
    consistent when modules and the core server are compiled at
    different times, this information is now available through the
    core API routine ap_get_server_version().  The use of
    the SERVER_VERSION symbol is deprecated.  Also,
    ap_get_server_built() returns a string representing
    the time the core server was linked.
 
ServerTokens, allows the Webmaster
    to change the value of the Server response header
    field which is sent back to clients.  The ServerTokens
    directive controls whether the server will include a non-specific
    note in the server identity about the type of operating system on
    which the server is running as well as included module information.
    As of Apache 1.3, this additional information is included by default.
{SHA1} are taken
    as Base64 encoded SHA1 passwords. More information and
    some utilities to convert Netscape ldap/ldif entries can be
    found in support/SHA1. 
