It was at a previous shop so I no longer have access to the code but basically it used a call to Get-Content that limited the rows to "the first one" to get the first line of the file, i.e. the column headers. I would store the first line of each data file to a new file for safe keeping. Then I would compare the new file's first line to the first line from the data file I received before it, and basically that was just doing another Get-Content to get the headers from the last file and an equality check with this-time's headers. If they did not match I would stop the process so someone could manually intervene because it meant the file format changed.