Use latitude longitude coordinates to build shapefile for GIS

I need at least a makeshift way to create a shapefile (and shx/dbf too). I’ve found some information on Google, but I know very little about shapefiles and none of it seems to work for what I need.

I am using PHP, so I would like to build it in PHP, but if anyone knows anything out there that I could use then please provide details! The data I have is simply 2 coordinates, one being a top-right coordinate and a bottom-left coordinate of a rectangle. Of course I can make the top-left and bottom-right corners with those; the coordinates won’t match up 100% with the section corners, but it’s close enough for my purposes.

Well I did stumble on BytesFall ShapeFiles which looks quite promising. I haven’t had time to test it, but it looks good.