APXS(8) OpenBSD System Manager's Manual APXS(8)NAMEapxs - APache eXtenSion tool
SYNOPSISapxs-c [-D variable[=value]] [-I incdir] [-L libdir] [-l libname]
[-o dsofile] [-S variable=value] [-Wc,compiler-flags]
[-Wl,linker-flags] file ...
apxs-e [-Aa] [-n name] [-S variable=value] dsofile ...
apxs-g [-S variable=value] -n name
apxs-i [-Aa] [-n name] [-S variable=value] dsofile ...
apxs-q [-S variable=value] query ...
DESCRIPTIONapxs is a tool for building and installing extension modules for the
Apache HyperText Transfer Protocol (HTTP) server, httpd(8). This is
achieved by building a Dynamic Shared Object (DSO) from one or more
source or object files which can then be loaded into httpd at runtime via
the LoadModule directive from mod_so. To use this extension mechanism,
your platform has to support the DSO feature and the httpd binary has to
be built with the mod_so module. The apxs tool automatically complains
if this is not the case. Check by manually running the following
command:
$ httpd -l
The module mod_so should be part of the displayed list. If these
requirements are fulfilled, httpd's functionality can be extended by
installing modules with the DSO mechanism, with the help of the apxs
tool:
# apxs-i -a -c mod_foo.c
cc -O2 -pipe -DDEV_RANDOM=/dev/arandom -DMOD_SSL=208116 -DEAPI -DUSE_EXPAT -I../lib/expat-lite -DUSE_SETUSERCONTEXT -fPIC -DSHARED_MODULE -I/usr/lib/apache/include -c mod_foo.c
[activating module `foo' in /var/www/conf/httpd.conf]
cp mod_foo.so /usr/lib/apache/modules/mod_foo.so
chmod 755 /usr/lib/apache/modules/mod_foo.so
cp /var/www/conf/httpd.conf /var/www/conf/httpd.conf.bak
cp /var/www/conf/httpd.conf.new /var/www/conf/httpd.conf
rm /var/www/conf/httpd.conf.new
# apachectl restart
/usr/sbin/apachectl restart: httpd not running, trying to start
/usr/sbin/apachectl restart: httpd started
The argument file can be any C source file (.c), an 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, whereas 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 Independent Code (PIC) to be able to use them
for a DSO. For instance, with cc(1) just use -fpic. For other C
compilers, please consult their manual pages 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.
The options are as follows:
-A Same as the -a option but the created LoadModule directive is
prefixed with a hash sign (#), i.e. the module is just prepared
for later activation but initially disabled.
-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.
-c Compile. This option first compiles the C source files (.c) of
file ... 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 file ... If no -o option is
specified, the output file is guessed from the first filename in
file ... and thus usually defaults to mod_name.so
-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.
-e Edit. This option can be used with the -a and -A options to edit
the configuration file, /var/www/conf/httpd.conf, without
attempting to install the module.
-g Template generation. This option generates a subdirectory name
(see the -n option) and 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.
-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.
-i Install. This option installs one or more DSOs into the server's
libexec directory.
-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.
-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, apxs
tries to determine the name from the source or (as a fallback) at
least by guessing it from the filename.
-o dsofile
Explicitly specifies the filename of the created DSO file. If
not specified and the name cannot be guessed from the file ...
list, the fallback name mod_unknown.so is used.
-q Query. This option 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
the following inside your own Makefiles if you need manual access
to Apache's C header files:
INC=-I`apxs -q INCLUDEDIR`
-S variable=value
This option changes the apxs settings described above.
-Wc,compiler-flags
This option passes compiler-flags as additional flags to the
compiler command. Use this to add local compiler-specific
options. This option may be specified multiple times in order to
pass multiple flags.
-Wl,linker-flags
This option passes linker-flags as additional flags to the linker
command. Use this to add local linker-specific options. This
option may be specified multiple times in order to pass multiple
flags.
EXAMPLES
Assume you have a module named ``mod_foo.c'' available which should
extend httpd's functionality. To accomplish this, first compile the C
source into a DSO suitable for loading into httpd at runtime via the
following command:
# apxs-c mod_foo.c
cc -O2 -pipe -DDEV_RANDOM=/dev/arandom -DMOD_SSL=208116 -DEAPI -DUSE_EXPAT -I../lib/expat-lite -DUSE_SETUSERCONTEXT -fPIC -DSHARED_MODULE -I/usr/lib/apache/include -c mod_foo.c
cc -shared -fPIC -DSHARED_MODULE -o mod_foo.so mod_foo.o
Then a LoadModule directive has to be added to httpd's configuration file
to load the DSO. To simplify this step, apxs provides an automatic way
to install the DSO in the ``libexec'' directory and update the httpd.conf
file accordingly. This can be achieved by running the following:
$ apxs-i -a mod_foo.so
[activating module `foo' in /var/www/conf/httpd.conf]
cp mod_foo.so /usr/lib/apache/modules/mod_foo.so
chmod 755 /usr/lib/apache/modules/mod_foo.so
cp /var/www/conf/httpd.conf /var/www/conf/httpd.conf.bak
cp /var/www/conf/httpd.conf.new /var/www/conf/httpd.conf
rm /var/www/conf/httpd.conf.new
This way a line such as the following is added to the configuration file:
LoadModule foo_module /usr/lib/apache/modules/mod_foo.so
If you want the module added to the configuration file without it being
enabled, use the -A option instead:
$ apxs-i -A mod_foo.so
For a quick test of the apxs mechanism, create a sample module template
plus a corresponding Makefile via:
# apxs-g -n foo
Creating [DIR] foo
Creating [FILE] foo/Makefile
Creating [FILE] foo/mod_foo.c
The sample module can then be immediately compiled into a DSO and loaded
into the httpd server:
$ cd foo
$ make all reload
apxs-c mod_foo.c
cc -O2 -pipe -DDEV_RANDOM=/dev/arandom -DMOD_SSL=208116 -DEAPI -DUSE_EXPAT -I../lib/expat-lite -DUSE_SETUSERCONTEXT -fPIC -DSHARED_MODULE -I/usr/lib/apache/include -c mod_foo.c
cc -shared -fPIC -DSHARED_MODULE -o mod_foo.so mod_foo.o
apxs-i -a -n 'foo' mod_foo.so
[activating module `foo' in /var/www/conf/httpd.conf]
cp mod_foo.so /usr/lib/apache/modules/mod_foo.so
chmod 755 /usr/lib/apache/modules/mod_foo.so
cp /var/www/conf/httpd.conf /var/www/conf/httpd.conf.bak
cp /var/www/conf/httpd.conf.new /var/www/conf/httpd.conf
rm /var/www/conf/httpd.conf.new
apachectl restart
/usr/sbin/apachectl restart: httpd not running, trying to start
/usr/sbin/apachectl restart: httpd started
apxs can even be used to compile complex modules outside the httpd source
tree, like PHP3, because apxs automatically recognizes 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 ALSOcc(1), apachectl(8), httpd(8)OpenBSD 4.9 May 31, 2007 OpenBSD 4.9