Script for managing ~/Downloads. Works relatively well, though it sometimes misses things.

tmpclean-mac.sh

#!/bin/bash

# Keep Downloads folder clean on a mac using xattr to track age.
# Normally, stick something like this in your crontab. It's pretty quick
# and not I/O intentisve, so I run every hour on some random time.
#
# Example crontab:
#  37 * * * * LOGME=1 /Users/james/bin/tmpclean-mac.sh /Users/james/Downloads 7

dir="$1"
age="$2"
if [ -z "$dir" ] || [ -z "$age" ]; then
  exec 1>&2
  echo
  echo "Usage: $0 DIR AGE"
  echo
  echo "  Delete things in DIR that are older than AGE days, unless:"
  echo "  - They have been accessed AGE days ago [if they're a file]"
  echo "  - Files inside them have been accessed <AGE days ago [if they're a dir]"
  echo
  exit 1
fi

if [ -n "$QUIET" ]; then
  exec 1>/dev/null
  exec 2>/dev/null
fi

if [ -n "$LOGME" ]; then
  logfile="$dir/.clean-log.$(date +%Y%m%d.%H%M)"
  exec 1>>$logfile
  exec 2>>$logfile
fi

ATTR=org.grickle.tmpclean.first-seen
NOW=$(date +%s)
CUTOFF=$(( $NOW - $age * 3600 * 24 ))

set -e
cd "$dir"
ls -A | while read file; do
  if xattr -l "$file" | grep -q "$ATTR"; then
    first_seen=$(xattr -p "$ATTR" "$file")
    recent=$(find "$file" -type f -atime +"$age"d)

    if [ "$first_seen" -lt "$CUTOFF" -a -n "$recent" ]; then
      echo "Deleting: $file"
      rm -fr "$file"
    else
      reason=""
      [ "$first_seen" -ge "$CUTOFF" ] && reason="xattr $reason"
      [ -z "$recent" ] && reason="atime $reason"

      echo "Not stale: $file. Reason $reason"
    fi
  else
    echo "New file: $file"
    xattr -w "$ATTR" "$NOW" "$file"
  fi
done