cmake(1) . -DCMAKE_INSTALL_PREFIX=/home/user/my_directory
Cross-Platform Makefile Generator
-D <var>:<type>=<value>
       Create a cmake cache entry.

       When cmake is first run in an empty build tree, it creates a CMakeCache.txt file and populates  it
       with  customizable  settings  for  the project.  This option may be used to specify a setting that
       takes priority over the project's default value.  The option may be repeated  for  as  many  cache
       entries as desired.
-C <initial-cache>
       Pre-load a script to populate the cache.

       When cmake is first run in an empty build tree, it creates a CMakeCache.txt file and populates  it
       with  customizable settings for the project.  This option may be used to specify a file from which
       to load cache entries before the first pass through the project's  cmake  listfiles.   The  loaded
       entries  take priority over the project's default values.  The given file should be a CMake script
       containing SET commands that use the CACHE option, not a cache-format file.
source manpages: cmake