Warning: file_get_contents(url): failed to open stream: No error in,该怎么解决

Warning: file_get_contents(url): failed to open stream: No error in
 Warning: file_get_contents(www.baidu.com/s?q1=&q2=able+able&q3=&q4=&rn=50&lm=0&ct=0&ft=&q5=&q6=&tn=baiduadv): failed to open stream: No error in 
问题描述：file_get_contents('www.baidu.com/s?q1=&q2='.$fw.'+'.$sw.'&q3=&q4=&rn=50&lm=0&ct=0&ft=&q5=&q6=&tn=baiduadv')会自动转义为上面的内容？导致出错？？怎样解决？？
------解决思路----------------------
file_get_contents('http://www.baidu.com/s?q1=&q2='.$fw.'+'.$sw.'&q3=&q4=&rn=50&lm=0&ct=0&ft=&q5=&q6=&tn=baiduadv')
------解决思路----------------------