# HG changeset patch
# Parent 256a83a960ce84da47c9cbb4113a26fdf25da428
Implement the echo command in forth and an example of a built-in
command in forth.

diff -r 256a83a960ce sys/boot/forth/loader.4th
--- a/sys/boot/forth/loader.4th
+++ b/sys/boot/forth/loader.4th
@@ -120,10 +120,28 @@ only forth also support-functions also b
   ?dup 0= if 0 1 autoboot then
 ;
 
+\ ***** echo4th
+\
+\	Echo the command arguments back.
+\ NB: Not too useful, except as an example of argument parsing in FORTH
+\ for new built-in comands.
+: echo4th
+  \ First argument is 0 when we're interprated.  See support.4th
+  \ for get_arguments reading the rest of the line and parsing it
+  0= if ( interpreted ) get_arguments then
+  \ stack: argN lenN ... arg1 len1 N
+  0 do		\ loop 0 to N - 1
+    type	\ Pop length and address off and print it.
+    32 emit	\ followed by a space
+  loop
+  cr
+;
+
 also forth definitions also builtins
 
 builtin: boot
 builtin: boot-conf
+builtin: echo4th
 
 only forth definitions also support-functions
 
@@ -245,4 +263,3 @@ include /boot/check-password.4th
 ; immediate \ interpret immediately for access to `source' (aka tib)
 
 only forth also
-