The precess program is given a right ascension and declination for the year 2000, and a year to precess these positions to, and it prints the precessed right ascension and declination.
I wrote the program.
The precess program is run like this:
Usage: precess right_ascension declination year
right_ascension and declination are in decimal hours and degrees, respectively
Note that you can't use minutes and seconds, just decimal hours and degrees.
Example:
precess 3.789 -23.331 1492
and it tells you
R.A. = 3.424 hours Dec = -24.984 degrees