+ Environment Variables
+ ---------------------
+
+ A number of environment variables can be used to provide additional control
+ over the build process. Typically these should be defined prior to running
+ config or Configure. Not all environment variables are relevant to all
+ platforms.
+
+ AR
+ The name of the ar executable to use.
+
+ BUILDFILE
+ Use a different build file name than the platform default
+ ("Makefile" on Unixly platforms, "makefile" on native Windows,
+ "descrip.mms" on OpenVMS). This requires that there is a
+ corresponding build file template. See Configurations/README
+ for further information.
+
+ CC
+ The compiler to use. Configure will attempt to pick a default
+ compiler for your platform but this choice can be overridden
+ using this variable. Set it to the compiler executable you wish
+ to use, e.g. "gcc" or "clang".
+
+ CROSS_COMPILE
+ This environment variable has the same meaning as for the
+ "--cross-compile-prefix" Configure flag described above. If both
+ are set then the Configure flag takes precedence.
+
+ NM
+ The name of the nm executable to use.
+
+ OPENSSL_LOCAL_CONFIG_DIR
+ OpenSSL comes with a database of information about how it
+ should be built on different platforms as well as build file
+ templates for those platforms. The database is comprised of
+ ".conf" files in the Configurations directory. The build
+ file templates reside there as well as ".tmpl" files. See the
+ file Configurations/README for further information about the
+ format of ".conf" files as well as information on the ".tmpl"
+ files.
+ In addition to the standard ".conf" and ".tmpl" files, it is
+ possible to create your own ".conf" and ".tmpl" files and store
+ them locally, outside the OpenSSL source tree. This environment
+ variable can be set to the directory where these files are held
+ and will have Configure to consider them in addition to the
+ standard ones.
+
+ PERL
+ The name of the Perl executable to use when building OpenSSL.
+
+ HASHBANGPERL
+ The command string for the Perl executable to insert in the
+ #! line of perl scripts that will be publically installed.
+ Default: /usr/bin/env perl
+ Note: the value of this variable is added to the same scripts
+ on all platforms, but it's only relevant on Unix-like platforms.
+
+ RC
+ The name of the rc executable to use. The default will be as
+ defined for the target platform in the ".conf" file. If not
+ defined then "windres" will be used. The WINDRES environment
+ variable is synonymous to this. If both are defined then RC
+ takes precedence.
+
+ RANLIB
+ The name of the ranlib executable to use.
+
+ WINDRES
+ See RC.
+
+ Makefile targets
+ ----------------
+
+ The Configure script generates a Makefile in a format relevant to the specific
+ platform. The Makefiles provide a number of targets that can be used. Not all
+ targets may be available on all platforms. Only the most common targets are
+ described here. Examine the Makefiles themselves for the full list.
+
+ all
+ The default target to build all the software components.
+
+ clean
+ Remove all build artefacts and return the directory to a "clean"
+ state.
+
+ depend
+ Rebuild the dependencies in the Makefiles. This is a legacy
+ option that no longer needs to be used in OpenSSL 1.1.0.
+
+ install
+ Install all OpenSSL components.
+
+ install_sw
+ Only install the OpenSSL software components.
+
+ install_docs
+ Only install the OpenSSL documentation components.
+
+ install_man_docs
+ Only install the OpenSSL man pages (Unix only).
+
+ install_html_docs
+ Only install the OpenSSL html documentation.
+
+ list-tests
+ Prints a list of all the self test names.
+
+ test
+ Build and run the OpenSSL self tests.
+
+ uninstall
+ Uninstall all OpenSSL components.
+
+ update
+ This is a developer option. If you are developing a patch for
+ OpenSSL you may need to use this if you want to update
+ automatically generated files; add new error codes or add new
+ (or change the visibility of) public API functions. (Unix only).