fbquestion.bash

# You have a proprietary file system type (myfs) with a custom set of command line tools.
# You need to clean up all files with a modification time older than 24 hours.
# Any directories left empty as a result of this cleanup should also be removed as well.
#
# The command to list a directory is 'myfs ls'
# The command to list a directory recursively is 'myfs lr'
# The command to delete a file or directory is 'myfs rm'
#
# The root uri of the filesystem is 'myfs://myserver/'
#
# For example, the output from running 'myfs lr myfs://myserver/' might result
# in the following output:
#
# drwxr-xr-x root root 0 2010-07-01 07:40 /mydirectory1
# -rw-r--r-- root root 1352 2010-07-09 08:42 /mydirectory1/myfile1.txt
# -rw-r--r-- root root 129772 2010-07-09 09:31 /mydirectory1/myfile2.txt
# drwxr-xr-x root root 0 2010-07-01 07:46 /mydirectory2
# -rw-r--r-- root root 1032 2010-07-09 10:42 /mydirectory2/myfile3.txt
# -rw-r--r-- root root 103522 2010-07-09 11:21 /mydirectory2/myfile4.txt
# -rw-r--r-- root root 103522 2010-07-09 11:21 /mydirectory2/a longer file name.txt
# drwxr-xr-x root root 0 2010-07-01 07:48 /mydirectory2/mydirectory3
# -rw-r--r-- root root 1032 2014-07-13 10:46 /mydirectory2/mydirectory3/myfile5.txt
# -rw-r--r-- root root 103522 2010-07-09 11:00 /mydirectory2/mydirectory3/myfile6.txt
# drwxr-xr-x root root 0 2010-07-01 07:46 /mydirectory4
# -rw-r--r-- root root 1032 2010-07-09 10:42 /mydirectory4/myfile7.txt
# -rw-r--r-- root root 103522 2010-07-09 11:21 /mydirectory4/myfile8.txt
# ...
#
# Write a script which cleans these old files from the myfs filesystem, and delete
# the directory if it's now empty (but not if the directory was already empty before cleanup).

#!/usr/bin/env bash

# /a/b/c/d.txt
# ...../a
# ...../a/b
# ...../a/b/c
# ...../a/b/c/d.txt

function empty_the_dir() {
    notpreviouslyempty=''
    fp=$(echo $1 | awk '{print $7}')
    if [ $(myfs lr $fp | wc -l) -le 1 ] then
        return
    fi
    for i in $(myfs lr $fp | tail --afterline 1)
        ago=$(echo $i | awk '{print $5 $6}')
        agoseconds=$(date +%s $ago)
        now=$(date +%s)
        fp=$(echo $i | awk '{print $7}')
        if [ $i ~= /^-/ ] && [ $(expr now - agoseconds) -gt 86400 ] then
            myfs rm fp
            notpreviouslyempty='true'
        fi
        if [ $i ~= /^d/ ] then
            empty_the_dir($i)
        fi
    ago=$(echo $1 | awk '{print $5 $6}')
    agoseconds=$(date +%s $ago)
    now=$(date +%s)
    if [ $(expr now - agoseconds) -gt 86400 ] && [ -n $notpreviouslyempty ] then
        myfs rm fp
    fi
}
    
for i in $(myfs lr myfs://mysever)
    empty_the_dir($i)

This took me almost 50 minutes to write. FML.