TED Talks

#!/bin/bash
# Filename: ted-talks.sh
# Version: 040716
# Author: robz
# A raspi script for downloading TED talks video using off peak bandwidth.
# Used as part of the interactive motd.sh script or just run in a terminal.
# You may need to "apt-get install at" this will also install heirloom-mailx
# packages but these can be removed afterwards if you wish without affecting
# the operation of the "at" utility.
#
dwn="$HOME/Downloads"
ted="$dwn/ted"                                      # Downloaded media here.
rss="$dwn/scripts/ted-rss.txt"                      # Feed location.
don="$dwn/scripts/ted-donelist.txt"                 # Shows already downloaded.
num="29"                                            # Number of choices in list.
# Get rss feed, refresh weekly.
if [[ ! -e "$rss" || $(find "$rss" -mtime +7) ]]; then
    echo "please wait - downloading new feed."
    wget -q -O - "https://www.ted.com/talks/rss" > "$rss"
fi
# Display choices list. (suits an 80 column terminal) 
lst=$(grep "<title" "$rss" | sed -e 's/<[^>]*>//g;1,2d;s/^[ \t]*//' | \
grep -v "$(sed 's/|.*//' < "$don")")                # Make list, exclude done.
top=$(sed q <<< "$lst")                             # Extract newest not viewed.
lst=$(grep -v "$top" <<< "$lst")                    # Remove duplicate entry.
lst=$(shuf -n"$num" <<< "$lst")                     # Shuffle the rest of list.
lst=$(echo -e "$top\n$lst")                         # Put newest talk at top.
echo " Popular TED talks."
echo -e "\n$lst\n" | nl -w3 -s ') ' | cut -c -79    # Number and trim to width.
echo
# Choose your TED talk.
read -p " Type in number - Enter, or just enter to cancel: " ans
# Reject nonsense inputs.
if [[ "$ans" -gt "$(( num+1 ))" || "$ans" -lt "1" ]]; then
    echo " Incorrect input, Hit enter."
    exit
fi
# Parse information for donelist and download.
tlk=$(echo "$lst" | sed "${ans}q;d")
echo -n "$tlk| " >> "$don"                          # Add title to donelist.
echo -e "\n $tlk"
tlk=$(grep -A4 "$tlk" "$rss" | grep "<enclosure" | \
sed 's/<.*url=\"//;s/\".*>//;s/^[ \t]*//')          # Parse url to download.
# Set job content and time to download.
echo "wget --content-disposition -P "$ted" "$tlk"" | at 01:11 > /dev/null 2>&1
echo " $tlk" | tee -a "$don"                        # Echo url & add to done.
echo -e "$(atq)\n Pending @ 01:11"                  # Query "at" to check job.
exit