APXS(1)                                                                apxs                                                                APXS(1)

NAME

       apxs - APache eXtenSion tool

SYNOPSIS

       apxs -g [ -S name=value ] -n modname

       apxs -q [ -v ] [ -S name=value ] query ...

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

       apxs -i [ -S name=value ] [ -n modname ] [ -a ] [ -A ] dso-file ...

       apxs -e [ -S name=value ] [ -n modname ] [ -a ] [ -A ] dso-file ...

SUMMARY

       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 run-
       time 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/modules/mod_foo.so
             chmod 755 /path/to/apache/modules/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  recog-
       nizes  these  extensions  and  automatically  used the C source files for compilation while just using the object and archive files for the
       linking phase. But when using such pre-compiled objects make sure they are compiled for position independent code (PIC) to be able  to  use
       them  for  a  dynamically  loaded shared object. For instance with GCC you always just have to use -fpic. For other C compilers consult its
       manual page or at watch for the flags apxs uses to compile the object files.

       For more details about DSO support in Apache read the documentation of mod_so or perhaps even read the src/modules/standard/mod_so.c source
       file.

OPTIONS

   Common Options
       -n modname
              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  fall-
              back) at least by guessing it from the filename.

   Query Options
       -q     Performs  a  query  for variables and environment settings used to build httpd. When invoked without query parameters, it prints all
              known variables and their values. The optional -v parameter formats the list output. .PP Use this  to  manually  determine  settings
              used to build the httpd that will load your module. For instance use INC=-I`apxs -q INCLUDEDIR` .PP inside your own Makefiles if you
              need manual access to Apache's C header files.

   Configuration Options
       -S name=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 Make-
              file for even easier build 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 dynamically shared object 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 dynamically shared object. If not specified and the name cannot be guessed from the
              files list, the fallback name mod_unknown.so is used.

       -D name=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 libtool --mode=compile command. Use this to add local compiler-specific
              options.

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

       -p     This option causes apxs to link against the apr/apr-util libraries. This is useful when  compiling  helper  programs  that  use  the
              apr/apr-util libraries.

   DSO Installation and Configuration Options
       -i     This indicates the installation operation and installs one or more dynamically shared objects into the server's modules 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 shared object suitable for loading into the Apache server under runtime via the following command:

             $ apxs -c mod_foo.c
             /path/to/libtool --mode=compile gcc ... -c mod_foo.c
             /path/to/libtool --mode=link gcc ... -o mod_foo.la mod_foo.slo
             $ _

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

             $ apxs -i -a mod_foo.la
             /path/to/instdso.sh mod_foo.la /path/to/apache/modules
             /path/to/libtool --mode=install cp mod_foo.la /path/to/apache/modules
             ...
             chmod 755 /path/to/apache/modules/mod_foo.so
             [activating module `foo' in /path/to/apache/conf/httpd.conf]
             $ _

       This way a line named

             LoadModule foo_module modules/mod_foo.so

       is added to the configuration file if still not present. If you want to have this disabled per default 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/modules.mk
             Creating [FILE] foo/mod_foo.c
             Creating [FILE] foo/.deps
             $ _

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

             $ cd foo
             $ make all reload
             apxs -c mod_foo.c
             /path/to/libtool --mode=compile gcc ... -c mod_foo.c
             /path/to/libtool --mode=link gcc ... -o mod_foo.la mod_foo.slo
             apxs -i -a -n "foo" mod_foo.la
             /path/to/instdso.sh mod_foo.la /path/to/apache/modules
             /path/to/libtool --mode=install cp mod_foo.la /path/to/apache/modules
             ...
             chmod 755 /path/to/apache/modules/mod_foo.so
             [activating module `foo' in /path/to/apache/conf/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
             $ _

Apache HTTP Server                                                  2013-06-20                                                             APXS(1)