I am surprised no one mentioned using %d.

You can list all nested subfolders, and sort them by depth, using:

find . -type d -printf '%d:%p\n' | sort -t: -k1 -g -r > /tmp/foo.txt

where

• . can be replaced with the root folder;
• -type d finds nested subfolders (replace with -type f for files instead);
• %d:%p prints the depth, followed by the path;
• -t: means the separator is :;
• -k1 means we want to sort by the first key/column;
• -g means that we want to sort numbers;
• -r means that we want the deepest folders to show first.

The result of this command are streamed into file /tmp/foo.txt (replace as desired, you can also use mktemp if needed).

The deepest level can then be determined automatically with:

D=$(head -n 1 /tmp/foo.txt | awk -F ":" '{print $1}')

If you want to filter only those folders or files at depth D, you can use:

awk -F ":" '{ if ($1 == D) print $2 }' /tmp/foo.txt 

Finally, to select a line randomly amongst the results, pipe with | shuf -n 1.

HTH

I am surprised no one mentioned using %d.

You can list all nested subfolders, and sort them by depth, using:

find . -type d -printf '%d:%p\n' | sort -t: -k1 -g -r > /tmp/foo.txt

where

• . can be replaced with the root folder;
• -type d finds nested subfolders (replace with -type f for files instead);
• %d:%p prints the depth, followed by the path;
• -t: means the separator is :;
• -k1 means we want to sort by the first key/column;
• -g means that we want to sort numbers;
• -r means that we want the deepest folders to show first.

The result of this command are streamed into file /tmp/foo.txt (replace as desired, you can also use mktemp if needed).

The deepest level can then be determined automatically with:

D=$(head -n 1 /tmp/foo.txt | awk -F ":" '{print $1}')

If you want to filter only those folders or files at depth D, you can use:

awk -F ":" '{ if ($1 == D) print $2 }' /tmp/foo.txt 

Finally, to select a line randomly amongst the results, pipe with | shuf -n 1.

Putting this into a script random_deep_file <Folder> <Depth>:

Folder=$1

# Sort files by depth into temporary file
Temp=$(mktemp)
find "$Folder" -type f -printf '%d:%p\n' | sort -t: -k1 -g -r >| "$Temp"

# Determine deepest level if not specified
[ $# -lt 2 ] && { D=$(head -n 1 "$Temp" | awk -F ":" '{print $1}'); } || D=$2

# Select a random file at that depth
awk -F ":" "{ if (\$1 == $D) print \$2 }" "$Temp" | shuf -n 1

Note: If you are on OSX, you need to install (with Homebrew) and use gfind and gshuf instead.

I am surprised no one mentioned using %d.

You can list all nested subfolders, and sort them by depth, using:

find . -type d -printf '%d:%p\n' | sort -t: -k1 -g -r

where

• . can be replaced with the root folder;
• -type d finds nested subfolders (not files);
• %d:%p prints the depth, followed by the path;
• -t: means the separator is :;
• -k1 means we want to sort by the first key/column;
• -g means that we want to sort numbers;
• -r means that we want the deepest folders to show first.

The result of this command can be streamed into a file using > /tmp/foo.txt for example.

If you want to filter only those folders at depth D, you can then use (piping the previous command, or processing the previous file /tmp/foo.txt):

awk -F ":" '{ if ($1 == D) print $2 }'

HTH

I am surprised no one mentioned using %d.

You can list all nested subfolders, and sort them by depth, using:

find . -type d -printf '%d:%p\n' | sort -t: -k1 -g -r > /tmp/foo.txt

where

• . can be replaced with the root folder;
• -type d finds nested subfolders (replace with -type f for files instead);
• %d:%p prints the depth, followed by the path;
• -t: means the separator is :;
• -k1 means we want to sort by the first key/column;
• -g means that we want to sort numbers;
• -r means that we want the deepest folders to show first.

The result of this command are streamed into file /tmp/foo.txt (replace as desired, you can also use mktemp if needed).

The deepest level can then be determined automatically with:

D=$(head -n 1 /tmp/foo.txt | awk -F ":" '{print $1}')

If you want to filter only those folders or files at depth D, you can use:

awk -F ":" '{ if ($1 == D) print $2 }' /tmp/foo.txt 

Finally, to select a line randomly amongst the results, pipe with | shuf -n 1.

HTH