Fix small bugs which didn't appear in tux but in local machine

hw3/dshlib.c

@@ -32,14 +32,6 @@
  *  Standard Library Functions You Might Want To Consider Using
  *      memset(), strcmp(), strcpy(), strtok(), strlen(), strchr()
  */
-int build_cmd_list(char *cmd_line, command_list_t *clist)
-{
-    char *pointer = cmd_line;
-    char* pipe = strchr(pointer, PIPE_CHAR);
-
-    clist->num = 0;
-
-    command_t new_command;
 
 void make_command(command_t new_command, char *pointer, command_list_t *clist, size_t sub_length){
     while (*pointer == ' '){
@@ -55,7 +47,10 @@ int build_cmd_list(char *cmd_line, command_list_t *clist)
         memset(new_command.args, 0, sizeof(new_command.args));
         new_command.args[0] = '\0';
 
+        if (clist->num < CMD_MAX){
             clist->commands[clist->num] = new_command;
+        
+        }
         clist->num = clist->num+1;
     } else{
         while (*space==' '){
@@ -70,12 +65,23 @@ int build_cmd_list(char *cmd_line, command_list_t *clist)
         memset(new_command.args, 0, sizeof(new_command.args));
         strncpy(new_command.args, space, arg_length);
         new_command.args[arg_length] = '\0';
+        if (clist->num < CMD_MAX){
             clist->commands[clist->num] = new_command;
+        
+        }
         clist->num = clist->num+1;
     }
 }
 
+int build_cmd_list(char *cmd_line, command_list_t *clist)
+{
+    char *pointer = cmd_line;
+    char* pipe = strchr(pointer, PIPE_CHAR);
+
+    clist->num = 0;
+
     while(pointer != NULL){
+        command_t new_command;
 
         pipe = strchr(pointer, PIPE_CHAR);