Beginnings of a simple shell.

ueforth/posix/shell.fs

@@ -0,0 +1,11 @@
+( Shell like words )
+vocabulary shell   shell definitions also posix
+512 constant max-path
+create cwd max-path allot   0 value cwd#
+: +cwd ( a n -- ) dup >r cwd cwd# + swap cmove r> cwd# + to cwd# ;
+: /+   s" /" +cwd ;  : /? cwd cwd# 1- + c@ [char] / = ;
+/+
+
+: pwd   cwd cwd# type cr ;
+: cd..   begin /? cwd# 1- to cwd# until ;
+: cd ( "name" ) bl parse /? 0= if /+ then +cwd ;