title: C++ - Reading Columns of a CSV files and only keeping ones that start with a specific string
body: <p>so I am trying to figure out how to sort CSV files to help organize data that I need for an economics paper. The files are massive and there are a lot of them (about 587 mb of zipper files). The files are organized by columns in that all the variable names are in the first line and all the data for that variable is all below it. My goal is to be able to only take the columns that start with the an indicated string (ex input: "MC1", Get: MC10RT2,MC1WE02,...) and then save them into a separate file. Does anyone have any advice as to what the form that the code should take?</p>