File: autoconf.info,  Node: Installation Names,  Next: Optional Features,  Prev: Multiple Architectures,  Up: Running configure Scripts

16.4 Installation Names
=======================

By default, ‘make install’ installs the package's commands under
‘/usr/local/bin’, include files under ‘/usr/local/include’, etc.  You
can specify an installation prefix other than ‘/usr/local’ by giving
‘configure’ the option ‘--prefix=PREFIX’, where PREFIX must be an
absolute file name.

   You can specify separate installation prefixes for
architecture-specific files and architecture-independent files.  If you
pass the option ‘--exec-prefix=PREFIX’ to ‘configure’, the package uses
PREFIX as the prefix for installing programs and libraries.
Documentation and other data files still use the regular prefix.

   In addition, if you use an unusual directory layout you can give
options like ‘--bindir=DIR’ to specify different values for particular
kinds of files.  Run ‘configure --help’ for a list of the directories
you can set and what kinds of files go in them.  In general, the default
for these options is expressed in terms of ‘${prefix}’, so that
specifying just ‘--prefix’ will affect all of the other directory
specifications that were not explicitly provided.

   The most portable way to affect installation locations is to pass the
correct locations to ‘configure’; however, many packages provide one or
both of the following shortcuts of passing variable assignments to the
‘make install’ command line to change installation locations without
having to reconfigure or recompile.

   The first method involves providing an override variable for each
affected directory.  For example, ‘make install
prefix=/alternate/directory’ will choose an alternate location for all
directory configuration variables that were expressed in terms of
‘${prefix}’.  Any directories that were specified during ‘configure’,
but not in terms of ‘${prefix}’, must each be overridden at install time
for the entire installation to be relocated.  The approach of makefile
variable overrides for each directory variable is required by the GNU
Coding Standards, and ideally causes no recompilation.  However, some
platforms have known limitations with the semantics of shared libraries
that end up requiring recompilation when using this method, particularly
noticeable in packages that use GNU Libtool.

   The second method involves providing the ‘DESTDIR’ variable.  For
example, ‘make install DESTDIR=/alternate/directory’ will prepend
‘/alternate/directory’ before all installation names.  The approach of
‘DESTDIR’ overrides is not required by the GNU Coding Standards, and
does not work on platforms that have drive letters.  On the other hand,
it does better at avoiding recompilation issues, and works well even
when some directory options were not specified in terms of ‘${prefix}’
at ‘configure’ time.