As in Informix? Why do this in C? You can easily do it in FoxPro, dBASE,
Clipper or whatever you used to make the .dbf files. If you don't have
xBASE tools and you really have to read the .dbf blind and make a pipe
delimited text file of it, you have a non trivial task at hand.
Faced with this situation some time ago, I identified the files of
interest to be .dbf, .txt, .sdf, .pip and wrote a suite of C programs to
convert one to another: d2p, p2d, d2t, d2s, etc. If you have some
commercial interest in these conversions I might be hired to do it for
you. If you just want to pick my brain, ask specific questions.