add a printenv implementation
diff --git a/coreutils/Config.in b/coreutils/Config.in
index a299506..466e8b8 100644
--- a/coreutils/Config.in
+++ b/coreutils/Config.in
@@ -164,6 +164,12 @@
 	  a command; without options it displays the current
 	  environment.
 
+config CONFIG_PRINTENV
+	bool "printenv"
+	default n
+	help
+	  printenv is used to print all or part of environment.
+
 config CONFIG_EXPR
 	bool "expr"
 	default n