在字符串中寻找子字符串

c语言代码，实现在一字符串中查询子字符串，如果找到，返回子字符串位置WritethefollowingfunctioninC.stripos—Findpositionoffirstoccurrenceofacase-insensitivestringintstripos(char*haystack,char*needle,intoffset)Returnsthenumericpositionofthefirstoccurrenceofneedleinthehaystackstring.Notethattheneedlemaybeastringofone