shell中的wget问题

#!/bin/bash
base_url="http://192.168.100.18:10068/writereport/"
wget -t 1 ${base_url}index.php?action=fill_user_info   -O /dev/null
wget -t 1 ${base_url}index.php?action=fill_track_info   -O /dev/null
以上是shell代码
总是出现以下错误
[root@bogon tool]# sh -x wget_proc.sh 
+ base_url=$'http://192.168.100.18:10068/writereport/\r'
index.php?action=fill_user_info' -O $'/dev/null\r'rt/
--11:13:35--  http://192.168.100.18:10068/writereport/%0Dindex.php?action=fill_user_info
Connecting to 192.168.100.18:10068... 宸茶繛鎺ャ€?
                                                   宸插彂鍑?HTTP 璇锋眰锛屾鍦ㄧ瓑寰呭洖搴?.. 404 Not Found
11:13:35 閿欒 404锛歂ot Found銆?index.php?action=fill_track_info' -O $'/dev/null\r't/
--11:13:35--  http://192.168.100.18:10068/writereport/%0Dindex.php?action=fill_track_info
Connecting to 192.168.100.18:10068... 宸茶繛鎺ャ€?
                                                   宸插彂鍑?HTTP 璇锋眰锛屾鍦ㄧ瓑寰呭洖搴?.. 404 Not Found
11:13:35 閿欒 404锛歂ot Found銆?[root@bogon tool]# 
为什么变量后面总是有个\r  到URL中就变成了%0D