apxs

APXS(8)                              apxs                              APXS(8)



NAME
       apxs - APache eXtenSion tool


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


       apxs -q [ -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
       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/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 recognizes
       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
              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
              strings: CC, CFLAGS, CFLAGS_SHLIB, INCLUDEDIR, LD_SHLIB,
              LDFLAGS_SHLIB, LIBEXECDIR, LIBS_SHLIB, SBINDIR, SYSCONFDIR,
              TARGET. .PP Use this for manually determining settings. 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
              Makefile 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.


   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
       accordingly. 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                2012-03-21                           APXS(8)