diff --git a/xdu.c b/xdu.c
index 4cc3dc7..7347dea 100644
--- a/xdu.c
+++ b/xdu.c
@@ -88,12 +88,12 @@ int ncols = NCOLS;
  * internal routines 
  */
 // char *strdup();
-void addtree();
-void parse_file();
-void parse_entry();
+static void addtree();
+static void parse_file();
+static void parse_entry();
 void dumptree();
-void clearrects();
-void sorttree();
+static void clearrects();
+static void sorttree();
 
 /*
  * order to sort paths by 
@@ -139,7 +139,7 @@ long nnodes = 0;
 /*
  * create a new node with the given name and size info
  */
-struct node*
+static struct node*
 makenode(char* name, long long size)
 {
     struct node* np;
@@ -157,7 +157,7 @@ makenode(char* name, long long size)
  * Return the node (if any) which has a draw rectangle containing
  * the given x,y point.
  */
-struct node*
+static struct node*
 findnode(struct node* treep, int x, int y)
 {
     struct node* np;
@@ -188,7 +188,7 @@ findnode(struct node* treep, int x, int y)
 /*
  * return a count of the number of children of a given node
  */
-int numchildren(struct node* nodep)
+static int numchildren(struct node* nodep)
 {
     int n;
 
@@ -207,7 +207,7 @@ int numchildren(struct node* nodep)
  *            had their sizes initialized. [DPT911113]
  *            * * * This function is recursive * * *
  */
-long fix_tree(struct node* top)
+static long fix_tree(struct node* top)
 {
     struct node* nd;
 
@@ -278,7 +278,7 @@ int main(int argc, char** argv)
     exit(0);
 }
 
-void parse_file(char* filename)
+static void parse_file(char* filename)
 {
     char buf[4096];
     char name[4096];
@@ -317,7 +317,7 @@ void parse_file(char* filename)
 /*
  * bust up a path string and link it into the tree 
  */
-void parse_entry(char* name, long long size)
+static void parse_entry(char* name, long long size)
 {
     char* path[MAXDEPTH]; /* break up path into this list */
     char buf[MAXNAME]; /* temp space for path element
@@ -369,7 +369,7 @@ void parse_entry(char* name, long long size)
  *          0 if it is a toss up.
  *          1 if it should go after.
  */
-int compare(struct node* n1, struct node* n2, int order)
+static int compare(struct node* n1, struct node* n2, int order)
 {
     switch (order) {
     case ORD_SIZE:
@@ -424,7 +424,7 @@ int compare(struct node* n1, struct node* n2, int order)
 /*
  * add path as a child of top - recursively 
  */
-void addtree(struct node* top, char* path[], long long size)
+static void addtree(struct node* top, char* path[], long long size)
 {
     struct node* np;
 
@@ -493,7 +493,7 @@ void dumptree(struct node* np, int level)
     }
 }
 
-void sorttree(struct node* np, int order)
+static void sorttree(struct node* np, int order)
 {
     struct node* subnp;
     struct node *np0,
@@ -541,7 +541,7 @@ void sorttree(struct node* np, int order)
  * Draws all children of a node within the given rectangle.
  * Recurses on children.
  */
-void drawchildren(struct node* nodep, struct rect rect)
+static void drawchildren(struct node* nodep, struct rect rect)
 {
     long long totalsize;
     int totalheight;
@@ -618,7 +618,7 @@ void drawchildren(struct node* nodep, struct rect rect)
  * Draws a node in the given rectangle, and all of its children
  * to the "right" of the given rectangle.
  */
-void drawnode(struct node* nodep, struct rect rect)
+static void drawnode(struct node* nodep, struct rect rect)
 {
     struct rect subrect;
 
@@ -651,7 +651,7 @@ void drawnode(struct node* nodep, struct rect rect)
  * clear the rectangle information of a given node
  * and all of its decendents
  */
-void clearrects(struct node* nodep)
+static void clearrects(struct node* nodep)
 {
     struct node* np;
 
@@ -671,7 +671,7 @@ void clearrects(struct node* nodep)
     }
 }
 
-void pwd(void)
+static void pwd(void)
 {
     struct node* np;
     struct node* stack[MAXDEPTH];
@@ -702,7 +702,7 @@ void pwd(void)
 }
 
 #ifdef NEED_STRDUP
-char* strdup(char* s)
+static char* strdup(char* s)
 {
     int n;
     char* cp;
@@ -874,7 +874,7 @@ XDU Version %s - Keyboard Commands\n\
         XDU_VERSION);
 }
 
-void fprintpsstart(FILE* fp)
+static void fprintpsstart(FILE* fp)
 {
     fprintf(fp,
         "%%!\n"
@@ -901,7 +901,7 @@ void fprintpsstart(FILE* fp)
         "/xduorigctm matrix currentmatrix def\n\n");
 }
 
-void fprintpsend(FILE* fp)
+static void fprintpsend(FILE* fp)
 {
     fprintf(fp,
         "grestore\n"
@@ -914,7 +914,7 @@ void fprintpsend(FILE* fp)
         "%%%%EOF\n");
 }
 
-void fprintpsbox(FILE* fp, int x1, int y1, int x2, int y2)
+static void fprintpsbox(FILE* fp, int x1, int y1, int x2, int y2)
 {
     fprintf(fp,
         "%%BOX\n"
@@ -932,7 +932,7 @@ void fprintpsbox(FILE* fp, int x1, int y1, int x2, int y2)
         x1, y1, x2 + x1, y1, x2 + x1, y2 + y1, x1, y2 + y1);
 }
 
-void fprintpstext(FILE* fp, int x, int y, char* s)
+static void fprintpstext(FILE* fp, int x, int y, char* s)
 {
     fprintf(fp,
         "%%TEXT\n"
@@ -945,7 +945,7 @@ void fprintpstext(FILE* fp, int x, int y, char* s)
         x, y, s);
 }
 
-void savepschildren(FILE* fp, struct node* nodep, struct rect rect, int showsize)
+static void savepschildren(FILE* fp, struct node* nodep, struct rect rect, int showsize)
 {
     long long size, totalsize;
     int totalheight,
@@ -1016,7 +1016,7 @@ void savepschildren(FILE* fp, struct node* nodep, struct rect rect, int showsize
     }
 }
 
-void savepsnode(FILE* fp, struct node* nodep, struct rect rect, int showsize)
+static void savepsnode(FILE* fp, struct node* nodep, struct rect rect, int showsize)
 {
     struct rect subrect;
     char label[1024],
@@ -1081,24 +1081,24 @@ void savetops(char* fname, int showsize)
     }
 }
 
-void fprintsvgstart(FILE* fp, int width, int height)
+static void fprintsvgstart(FILE* fp, int width, int height)
 {
     fprintf(fp, "<?xml version=\"1.0\"?>\n<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"%d\" height=\"%d\">\n", width, height);
 }
 
-void fprintsvgend(FILE* fp)
+static void fprintsvgend(FILE* fp)
 {
     fprintf(fp, "</svg>");
 }
 
-void fprintsvgnode(FILE* fp, struct rect rect)
+static void fprintsvgnode(FILE* fp, struct rect rect)
 {
     fprintf(fp,
         "    <rect x=\"%d\" y=\"%d\" width=\"%d\" height=\"%d\" stroke=\"black\" stroke-width=\"1px\" fill=\"white\"/>\n",
         rect.left, rect.top, rect.width, rect.height);
 }
 
-void fprintsvgnodetext(FILE* fp, int x, int y, long long size, char* name, int showsize)
+static void fprintsvgnodetext(FILE* fp, int x, int y, long long size, char* name, int showsize)
 {
     char buffer[1024],
         *text="n/a";
@@ -1135,7 +1135,7 @@ void fprintsvgnodetext(FILE* fp, int x, int y, long long size, char* name, int s
         x, y, text);
 }
 
-void savesvgnode(FILE* fp, struct node* nodep, int showsize, int depth)
+static void savesvgnode(FILE* fp, struct node* nodep, int showsize, int depth)
 {
     struct node* np;