This document is intended to help you quickly start writing C programs to read and write FITS files using the CFITSIO library. It covers the most important CFITSIO routines that are needed to perform most types of operations on FITS files. For more complete information about these and all the other available routines in the library please refer to the ``CFITSIO User's Reference Guide'', which is available from the CFITSIO Web site at http://heasarc.gsfc.nasa.gov/fitsio.
For more general information about the FITS data format, refer to the
following web page:
http://heasarc.gsfc.nasa.gov/docs/heasarc/fits.html