1 files changed, 140 insertions, 0 deletions
diff --git a/utils/rcsh/tree.c b/utils/rcsh/tree.c
new file mode 100644
index 00000000..145f9c77
--- /dev/null
+++ b/utils/rcsh/tree.c
@@ -0,0 +1,140 @@
+#include "rc.h"
+#include "y.tab.h"
+
+Tree *Treenodes;
+
+/*
+ * create and clear a new Tree node, and add it
+ * to the node list.
+ */
+Tree *
+newtree(void)
+{
+	Tree *t=new(Tree);
+	t->iskw=0;
+	t->str=0;
+	t->child[0]=t->child[1]=t->child[2]=0;
+	t->next=Treenodes;
+	Treenodes=t;
+	return t;
+}
+
+void
+freenodes(void)
+{
+	Tree *t, *u;
+	for(t=Treenodes;t;t=u){
+		u=t->next;
+		if(t->str)
+			free(t->str);
+		free(t);
+	}
+	Treenodes=0;
+}
+
+Tree *
+tree1(int type, Tree *c0)
+{
+	return tree3(type, c0, 0, 0);
+}
+
+Tree *
+tree2(int type, Tree *c0, Tree *c1)
+{
+	return tree3(type, c0, c1, 0);
+}
+
+Tree *
+tree3(int type, Tree *c0, Tree *c1, Tree *c2)
+{
+	Tree *t;
+	if(type==';'){
+		if(c0==0) return c1;
+		if(c1==0) return c0;
+	}
+	t=newtree();
+	t->type=type;
+	t->child[0]=c0;
+	t->child[1]=c1;
+	t->child[2]=c2;
+	return t;
+}
+
+Tree *
+mung1(Tree *t, Tree *c0)
+{
+	t->child[0]=c0;
+	return t;
+}
+
+Tree *
+mung2(Tree *t, Tree *c0, Tree *c1)
+{
+	t->child[0]=c0;
+	t->child[1]=c1;
+	return t;
+}
+
+Tree *
+mung3(Tree *t, Tree *c0, Tree *c1, Tree *c2)
+{
+	t->child[0]=c0;
+	t->child[1]=c1;
+	t->child[2]=c2;
+	return t;
+}
+
+Tree *
+epimung(Tree *comp, Tree *epi)
+{
+	Tree *p;
+	if(epi==0) return comp;
+	for(p=epi;p->child[1];p=p->child[1]);
+	p->child[1]=comp;
+	return epi;
+}
+
+/*
+ * Add a SIMPLE node at the root of t and percolate all the redirections
+ * up to the root.
+ */
+Tree *
+simplemung(Tree *t)
+{
+	Tree *u;
+	Io *s;
+	t=tree1(SIMPLE, t);
+	s=openstr();
+	pfmt(s, "%t", t);
+	t->str=strdup(s->strp);
+	closeio(s);
+	for(u=t->child[0];u->type==ARGLIST;u=u->child[0]){
+		if(u->child[1]->type==DUP
+		|| u->child[1]->type==REDIR){
+			u->child[1]->child[1]=t;
+			t=u->child[1];
+			u->child[1]=0;
+		}
+	}
+	return t;
+}
+
+Tree *
+token(char *str, int type)
+{
+	Tree *t=newtree();
+	t->type=type;
+	t->str=strdup(str);
+	return t;
+}
+
+void
+freetree(Tree *p)
+{
+	if(p==0) return;	
+	freetree(p->child[0]);
+	freetree(p->child[1]);
+	freetree(p->child[2]);
+	if(p->str) free(p->str);
+	free((char *)p);
+}