apxs

apxs(8)                     System Manager's Manual                    apxs(8)



NAME
       apxs - APache eXtenSion tool

SYNOPSIS
       apxs -g [ -S variable=value ] -n name

       apxs -q [ -S variable=value ] query ...

       apxs -c [ -S variable=value ] [ -o dsofile ] [ -I incdir ] [ -D
       variable[=value] ] [ -L libdir ] [ -l libname ] [ -Wc,compiler-flags ]
       [ -Wl,linker-flags ] files ...

       apxs -i [ -S variable=value ] [ -n name ] [ -a ] [ -A ] dsofile ...

       apxs -e [ -S variable=value ] [ -n name ] [ -a ] [ -A ] dsofile ...

DESCRIPTION
       apxs is a tool for building and installing extension modules for the
       Apache HyperText Transfer Protocol (HTTP) server. This is achieved by
       building a Dynamic Shared Object (DSO) from one or more source or
       object files which then can be loaded into the Apache server under
       runtime via the LoadModule directive from mod_so.

       So to use this extension mechanism, your platform has to support the
       DSO feature and your Apache httpd binary has to be built with the
       mod_so module.  The apxs tool automatically complains if this is not
       the case.  You can check this yourself by manually running the command

         $ httpd -l

       The module mod_so should be part of the displayed list.  If these
       requirements are fulfilled, you can easily extend your Apache server's
       functionality by installing your own modules with the DSO mechanism by
       the help of this apxs tool:

         $ apxs -i -a -c mod_foo.c
         gcc -fpic -DSHARED_MODULE -I/path/to/apache/include -c mod_foo.c
         ld -Bshareable -o mod_foo.so mod_foo.o
         cp mod_foo.so /path/to/apache/libexec/mod_foo.so
         chmod 755 /path/to/apache/libexec/mod_foo.so
         [activating module `foo' in /path/to/apache/etc/httpd.conf]
         $ apachectl restart
         /path/to/apache/sbin/apachectl restart: httpd not running, trying to start
         [Tue Mar 31 11:27:55 1998] [debug] mod_so.c(303): loaded module foo_module
         /path/to/apache/sbin/apachectl restart: httpd started
         $ _

       The arguments files can be any C source file (.c), a object file (.o)
       or even a library archive (.a). The apxs tool automatically recognizes
       these extensions and automatically uses the C source files for
       compilation while it just uses the object and archive files for the
       linking phase. But when using such pre-compiled objects, make sure they
       are compiled for Position Independend Code (PIC) to be able to use them
       for a DSO. For instance with GCC you always just have to use -fpic.
       For other C compilers please consult its manual page or watch for the
       flags apxs uses to compile the object files.

       For more details about DSO support in Apache, first read the background
       information about DSO in htdocs/manual/dso.html, then read the
       documentation of mod_so.


OPTIONS
       Common options:

       -n name     This explicitly sets the module name for the -i (install)
                   and -g (template generation) option. Use this to explicitly
                   specify the module name.  For option -g this is required,
                   for option -i the apxs tool tries to determine the name
                   from the source or (as a fallback) at least by guessing it
                   from the filename.

       Query options:

       -q          Performs a query for apxs's knowledge about certain
                   settings. The query parameters can be one or more of the
                   following variable names:
                     CC              TARGET
                     CFLAGS          SBINDIR
                     CFLAGS_SHLIB    INCLUDEDIR
                     LD_SHLIB        LIBEXECDIR
                     LDFLAGS_SHLIB   SYSCONFDIR
                     LIBS_SHLIB      PREFIX
                   Use this for manually determining settings. For instance
                   use
                     INC=-I`apxs -q INCLUDEDIR`
                   inside your own Makefiles if you need manual access to
                   Apache's C header files.

       Configuration options:

       -S variable=value
                   This option changes the apxs settings described above.

       Template Generation options:

       -g          This generates a subdirectory name (see option -n) and
                   there two files: A sample module source file named
                   mod_name.c which can be used as a template for creating
                   your own modules or as a quick start for playing with the
                   apxs mechanism.  And a corresponding Makefile for even
                   easier building and installing of this module.

       DSO compilation options:

       -c          This indicates the compilation operation. It first compiles
                   the C source files (.c) of files into corresponding object
                   files (.o) and then builds a DSO in dsofile by linking
                   these object files plus the remaining object files (.o and
                   .a) of files If no -o option is specified the output file
                   is guessed from the first filename in files and thus
                   usually defaults to mod_name.so

       -o dsofile  Explicitly specifies the filename of the created DSO file.
                   If not specified and the name cannot be guessed from the
                   files list, the fallback name mod_unknown.so is used.

       -D variable[=value]
                   This option is directly passed through to the compilation
                   command(s).  Use this to add your own defines to the build
                   process.

       -I incdir   This option is directly passed through to the compilation
                   command(s).  Use this to add your own include directories
                   to search to the build process.

       -L libdir   This option is directly passed through to the linker
                   command.  Use this to add your own library directories to
                   search to the build process.

       -l libname  This option is directly passed through to the linker
                   command.  Use this to add your own libraries to search to
                   the build process.

       -Wc,compiler-flags
                   This option passes compiler-flags as additional flags to
                   the compiler command.  Use this to add local compiler-
                   specific options.

       -Wl,linker-flags
                   This option passes linker-flags as additional flags to the
                   linker command.  Use this to add local linker-specific
                   options.

       DSO installation and configuration options:

       -i          This indicates the installation operation and installs one
                   or more DSOs into the server's libexec directory.

       -a          This activates the module by automatically adding a
                   corresponding LoadModule line to Apache's httpd.conf
                   configuration file, or by enabling it if it already exists.

       -A          Same as option -a but the created LoadModule directive is
                   prefixed with a hash sign (#), i.e. the module is just
                   prepared for later activation but initially disabled.

       -e          This indicates the editing operation, which can be used
                   with the -a and -A options similarly to the -i operation to
                   edit Apache's httpd.conf configuration file without
                   attempting to install the module.

EXAMPLES
       Assume you have an Apache module named mod_foo.c available which should
       extend Apache's server functionality. To accomplish this you first have
       to compile the C source into a DSO suitable for loading into the Apache
       server under runtime via the following command:

         $ apxs -c mod_foo.c
         gcc -fpic -DSHARED_MODULE -I/path/to/apache/include -c mod_foo.c
         ld -Bshareable -o mod_foo.so mod_foo.o
         $ _

       Then you have to update the Apache configuration by making sure a
       LoadModule directive is present to load this DSO. To simplify this step
       apxs provides an automatic way to install the DSO in the "libexec"
       directory and updating the httpd.conf file accordingly. This can be
       achieved by running:

         $ apxs -i -a mod_foo.c
         cp mod_foo.so /path/to/apache/libexec/mod_foo.so
         chmod 755 /path/to/apache/libexec/mod_foo.so
         [activating module `foo' in /path/to/apache/etc/httpd.conf]
         $ _

       This way a line named

         LoadModule foo_module libexec/mod_foo.so

       is added to the configuration file if still not present.  If you want
       to have this operation to be disabled, use the -A option, i.e.

         $ apxs -i -A mod_foo.c

       For a quick test of the apxs mechanism you can create a sample Apache
       module template plus a corresponding Makefile via:

         $ apxs -g -n foo
         Creating [DIR]  foo
         Creating [FILE] foo/Makefile
         Creating [FILE] foo/mod_foo.c
         $ _

       Then you can immediately compile this sample module into a DSO and load
       it into the Apache server:

         $ cd foo
         $ make all reload
         apxs -c mod_foo.c
         gcc -fpic -DSHARED_MODULE -I/path/to/apache/include -c mod_foo.c
         ld -Bshareable -o mod_foo.so mod_foo.o
         apxs -i -a -n "foo" mod_foo.so
         cp mod_foo.so /path/to/apache/libexec/mod_foo.so
         chmod 755 /path/to/apache/libexec/mod_foo.so
         [activating module `foo' in /path/to/apache/etc/httpd.conf]
         apachectl restart
         /path/to/apache/sbin/apachectl restart: httpd not running, trying to start
         [Tue Mar 31 11:27:55 1998] [debug] mod_so.c(303): loaded module foo_module
         /path/to/apache/sbin/apachectl restart: httpd started
         $ _

       You can even use apxs to compile complex modules outside the Apache
       source tree, like PHP3, because apxs automatically recognized C source
       files and object files.

         $ cd php3
         $ ./configure --with-shared-apache=../apache-1.3
         $ apxs -c -o libphp3.so mod_php3.c libmodphp3-so.a
         gcc -fpic -DSHARED_MODULE -I/tmp/apache/include  -c mod_php3.c
         ld -Bshareable -o libphp3.so mod_php3.o libmodphp3-so.a
         $ _

       Only C source files are compiled while remaining object files are used
       for the linking phase.


SEE ALSO
       apachectl(1), httpd(8).



                                  April 1998                           apxs(8)