I just used your example filenames.
Code:
# this line was file="20080501000001.dat"
ls -rt part1_*`date "+%Y%m%d`*.dat | tail -1 read file
This find the last occurrence of the file - ie. the highest sequence number for a file received today. the variable "file" is just the filename with the newsest sequence embedded in it.
Assuming I got your requirements.
