Cleanest way to get the highest suffix (or prefix) of a certain file type in a set of directories with bash?

Question

I have a set of data files across a number of directories with format

ls lcp01/output/
> dst000.dat dst001.dat ... dst075.dat nn000.dat nn001.dat ... nn036.dat aa000.dat aa001.dat ... aa040.dat

That is to say, there are a set of directories lcp01 through lcp25 with a collection of different data files in their output folders. I want to know what the highest number dstXXX.dat file is in each directory (in the example shown the result would be 75).

I wrote a script which achieves this, but I'm not satisfied with the final step which feels a bit hacky:

#!/bin/bash

for i in `seq -f "%02g" 1 25`; #specify dir extensions 1 through 25
do
    echo " "
    echo $i
    names=($(ls lcp$i/output | grep dst )) #dir containing dst files

    NUMS=()
    for j in "${names[@]}";
    do
            temp="$(echo $j | tr -dc '0-9' && printf " ")" # record suffixes for each dst file
            NUMS+=("$((10#$temp))") #force base 10 interpretation of dst suffixes
    done

    numList="$(echo "${NUMS[*]}" | sort -nr | head -n1)"
    echo ${numList:(-3)} #print out the last 3 characters of the sorted list - the largest file suffix
done

The final two steps organise the list of output indices, then I show the last 3 characters of that list which will be my largest file number (providing the file numbers are smaller than 100).

Is there a cleaner way of doing this? Ideally I would like more control over the output format, but mainly it's the step of reading the last 3 characters out. I would like to be able to just output the largest number, which should be the last element of the list but I cannot figure out how.

Answer 1

You could do something like the following:

for d in lc[0-9][0-9]; do find $d -name 'dst*.dat' -print | sort -u | tail -n1; done

Above command will only work if the numbering has the same number of digits (dst001..999.dat), as it is sorted as a string; if that's not the case:

for d in lc[0-9][0-9]; do echo -n $d: ; find $d -name 'dst*.dat' -print | grep -o '[0-9]*.dat' | sort -n | tail -n1; done