#! /bin/bash

## This shell scripts searches all .dat files in the present directory, and then append 
## the content of each .dat file into a target file called targetfile.

#mydir="$(echo $(pwd))"

numfiles=1000 #number to process
find -name "*.dat" -printf "%T@\t%p\n" |

sort -k1,1n |
tail -$numfiles |
cut -f2- |
while read file; do
echo processing $file

cat $file >> targetfile

done