* make these variables configurable from environment on Windows:

PEAR_INSTALLDIR           PHP_BINDIR      PHP_CONFIG_FILE_PATH
  PHP_CONFIG_FILE_SCAN_DIR  PHP_DATADIR     PHP_EXTENSION_DIR
  PHP_INCLUDE_PATH          PHP_LIBDIR      PHP_LOCALSTATEDIR
  PHP_PREFIX                PHP_SYSCONFDIR

main/config.w32.h.in

@@ -6,18 +6,20 @@
 */
 
 /* Default PHP / PEAR directories */
+#define CONDENV(ev,def) (getenv(ev)!=NULL?getenv(ev):def)
+
 #define CONFIGURATION_FILE_PATH "php.ini"
-#define PEAR_INSTALLDIR "c:\\php4\\pear"
-#define PHP_BINDIR "c:\\php4"
-#define PHP_CONFIG_FILE_PATH (getenv("SystemRoot"))?getenv("SystemRoot"):""
-#define PHP_CONFIG_FILE_SCAN_DIR ""
-#define PHP_DATADIR "c:\\php4"
-#define PHP_EXTENSION_DIR "c:\\php4"
-#define PHP_INCLUDE_PATH	".;c:\\php4\\pear"
-#define PHP_LIBDIR "c:\\php4"
-#define PHP_LOCALSTATEDIR "c:\\php4"
-#define PHP_PREFIX "c:\\php4"
-#define PHP_SYSCONFDIR "c:\\php4"
+#define PEAR_INSTALLDIR          CONDENV("PEAR_INSTALLDIR", "c:\\php4\\pear")
+#define PHP_BINDIR               CONDENV("PHP_BINDIR", "c:\\php4")
+#define PHP_CONFIG_FILE_PATH     CONDENV("SystemRoot", "")
+#define PHP_CONFIG_FILE_SCAN_DIR CONDENV("PHP_CONFIG_FILE_SCAN_DIR", "")
+#define PHP_DATADIR              CONDENV("PHP_DATADIR", "c:\\php4")
+#define PHP_EXTENSION_DIR        CONDENV("PHP_EXTENSION_DIR", "c:\\php4")
+#define PHP_INCLUDE_PATH         CONDENV("PHP_INCLUDE_PATH", ".;c:\\php4\\pear")
+#define PHP_LIBDIR               CONDENV("PHP_LIBDIR", "c:\\php4")
+#define PHP_LOCALSTATEDIR        CONDENV("PHP_LOCALSTATEDIR", "c:\\php4")
+#define PHP_PREFIX               CONDENV("PHP_PREFIX", "c:\\php4")
+#define PHP_SYSCONFDIR           CONDENV("PHP_SYSCONFDIR", "c:\\php4")
 
 /* Enable / Disable BCMATH extension (default: enabled) */
 #define WITH_BCMATH 1