20090420-1743

3 files changed, 27 insertions, 1 deletions

diff --git a/appl/cmd/m4.b b/appl/cmd/m4.b
index 9315bf55..f24427b6 100644
--- a/appl/cmd/m4.b
+++ b/appl/cmd/m4.b
@@ -65,6 +65,7 @@ init(nil: ref Draw->Context, args: list of string)
 
 	builtin("changecom", dochangecom);
 	builtin("changequote", dochangequote);
+	builtin("copydef", docopydef);
 	builtin("define", dodefine);
 	builtin("divert", dodivert);
 	builtin("divnum", dodivnum);
@@ -457,6 +458,20 @@ doundefine(args: array of string)
 		undefine(args[i]);
 }
 
+docopydef(args: array of string)
+{
+	if(len args > 2 && args[1] != args[2]){
+		undefine(args[2]);
+		if((n := lookup(args[1])) != nil){
+			if(n.impl == nil)
+				define(args[2], n.repl);
+			else
+				builtin(args[2], n.impl);
+		}else
+			define(args[2], "");
+	}
+}
+
 doeval(args: array of string)
 {
 	if(len args > 1)
@@ -683,6 +698,7 @@ dosyscmd(args: array of string)
 				if(sh == nil)
 					raise sys->sprint("load: can't load %s: %r", Sh->PATH);
 			}
+			bout.flush();
 			sh->system(nil, args[1]);
 		}exception e{
 		"load:*" =>
diff --git a/dis/m4.dis b/dis/m4.dis
index 0d9e9606..6911a452 100644
--- a/dis/m4.dis
+++ b/dis/m4.dis
diff --git a/man/1/m4 b/man/1/m4
index fcfb3e2d..dfab4fb0 100644
--- a/man/1/m4
+++ b/man/1/m4
@@ -77,9 +77,19 @@ Change quote characters to the first and second arguments.
 without arguments restores the original values of
 .BR `\|' .
 .TP
+copydef
+The second argument is installed with the value of the macro
+named by the first argument,
+which may be a built-in macro.
+Typically both arguments are quoted to prevent too early expansion.
+A macro can be renamed using
+.B copydef
+followed by
+.BR undefine .
+.TP
 define
 The second argument is installed as the value of the macro
-whose name is the first argument.
+named by the first argument.
 When the macro is later called (expanded),
 each occurrence in the replacement text of
 .BI $ n,