Question

I am trying to write a program that will search through a main directories sub-directories and list the files that have the largest number at the end. ex: filename_100.

find . -name "*_*" | sort -n | tail

Answer 1

sort sorts starting from the beginning of the string, so you can’t use it without first splitting off the leading part of the filename. This loop will do that; it prints out the part of the filename after the _, followed by the full filename.

for fn in `find . -name '*_*'`; do
    echo "${fn##*_} $fn"
done

Then you can pipe the output to sort and tail to get the largest number, and then to cut to pick out only the filename itself.

for fn in `find . -name '*_*'`; do
    echo "${fn##*_} $fn"
done | sort -n | tail -n 1 | cut -d' ' -f 2-

Then you’ll need to extract the part of the filename before the underscore. This is probably best done by storing the result of the last part in a variable,

largest_filename="$(for fn in `find . -name '*_*'`; do
    echo "${fn##*_} $fn"
done | sort -n | tail -n 1 | cut -d' ' -f 2-)"

after which you can use bash’s suffix removal to strip off the part after the underscore, and then list all files that share that prefix.

largest_filename="$(for fn in `find . -name '*_*'`; do
    echo "${fn##*_} $fn"
done | sort -n | tail -n 1 | cut -d' ' -f 2-)"
ls ${largest_filename%_*}_*