使用libcurl检索的标头信息来确定文件名

I am trying to parse the header information with libcurl in order to keep the original file name that I am downloading in tact. I am currently looking for the sub-string "Content-Disposition" in each line of the header in order to find the file name. I wrote the following code with the mindset of expanding the amount of sub-string I am looking for in the header data by editing an lookup table (explained below). The issue I am having is that no matter what urls I test my code against the header information NEVER contains the sub-string I am looking for (currently only "Content-Disposition: "). Why would I not be seeing this in the header info?I am trying to parse the header information wit