diff --git a/ls.c b/ls.c
index 3a29a75..cf22a45 100644
--- a/ls.c
+++ b/ls.c
@@ -3,10 +3,6 @@
 #include "user.h"
 #include "fs.h"
 
-char buf[512];
-struct stat st;
-struct dirent dirent;
-
 void
 pname(char *n)
 {
@@ -22,10 +18,11 @@ pname(char *n)
 int
 main(int argc, char *argv[])
 {
+  char buf[512], *p;
   int fd;
-  uint off;
-  uint sz;
-  char *p;
+  uint off, sz;
+  struct dirent de;
+  struct stat st;
 
   if(argc > 2){
     puts("Usage: ls [dir]\n");
@@ -58,12 +55,12 @@ main(int argc, char *argv[])
     break;
   case T_DIR:
     sz = st.size;
-    for(off = 0; off < sz; off += sizeof(struct dirent)) {
-      if(read(fd, &dirent, sizeof dirent) != sizeof dirent) {
+    for(off = 0; off < sz; off += sizeof(de)) {
+      if(read(fd, &de, sizeof(de)) != sizeof(de)) {
         printf(1, "ls: read error\n");
         break;
       }
-      if(dirent.inum != 0) {
+      if(de.inum != 0) {
         p = buf;
         if(argc == 2) {			  
           strcpy(p, argv[1]);
@@ -71,13 +68,14 @@ main(int argc, char *argv[])
           if(*(p-1) != '/')
             *p++ = '/';
         }
-        strcpy(p, dirent.name);
+        memmove(p, de.name, DIRSIZ);
+        p[DIRSIZ] = 0;
         if(stat(buf, &st) < 0) {
-          printf(1, "stat: failed %s\n", dirent.name);
+          printf(1, "stat: failed %s\n", de.name);
           continue;
         }
-        pname(dirent.name);
-        printf(1, "%d %d %d\n", st.type, dirent.inum, st.size);
+        pname(de.name);
+        printf(1, "%d %d %d\n", st.type, de.inum, st.size);
       }
     }
     break;