File: autoconf.info,  Node: Default Prefix,  Prev: Subdirectories,  Up: Setup

4.13 Default Prefix
===================

By default, ‘configure’ sets the prefix for files it installs to
‘/usr/local’.  The user of ‘configure’ can select a different prefix
using the ‘--prefix’ and ‘--exec-prefix’ options.  There are two ways to
change the default: when creating ‘configure’, and when running it.

   Some software packages might want to install in a directory other
than ‘/usr/local’ by default.  To accomplish that, use the
‘AC_PREFIX_DEFAULT’ macro.

 -- Macro: AC_PREFIX_DEFAULT (PREFIX)
     Set the default installation prefix to PREFIX instead of
     ‘/usr/local’.

   It may be convenient for users to have ‘configure’ guess the
installation prefix from the location of a related program that they
have already installed.  If you wish to do that, you can call
‘AC_PREFIX_PROGRAM’.

 -- Macro: AC_PREFIX_PROGRAM (PROGRAM)
     If the user did not specify an installation prefix (using the
     ‘--prefix’ option), guess a value for it by looking for PROGRAM in
     ‘PATH’, the way the shell does.  If PROGRAM is found, set the
     prefix to the parent of the directory containing PROGRAM, else
     default the prefix as described above (‘/usr/local’ or
     ‘AC_PREFIX_DEFAULT’).  For example, if PROGRAM is ‘gcc’ and the
     ‘PATH’ contains ‘/usr/local/gnu/bin/gcc’, set the prefix to
     ‘/usr/local/gnu’.