Separating sections of a text file with a bash script - bash

Question

I have a list:
### To Read:
One Hundred Years of Solitude | Gabriel García Márquez
Moby-Dick | Herman Melville
Frankenstein | Mary Shelley
On the Road | Jack Kerouac
Eyeless in Gaza | Aldous Huxley
### Read:
The Name of the Wind (The Kingkiller Chronicles: Day One) | Patrick Rothfuss | 6-27-2013
The Wise Man’s Fear (The Kingkiller Chronicles: Day Two) | Patrick Rothfuss | 8-4-2013
Vampires in the Lemon Grove | Karen Russell | 12-25-2013
Brave New World | Aldous Huxley | 2-2014
I'd like to use something like python's string.split(' | ') to separate the various fields into separate strings, but since the two sections have different numbers of fields, I think I need to treat them differently. How do I go about selecting the lines in between '### To Read:' and '### Read:' and after '### Read:' and splitting them? Should I use awk or sed?

Answer 1

You have not specified any desired output. So, as I interpret your question, you want to read certain lines from a file, split the lines on '|' and, analogous to python lists, put the results in bash arrays. The specified lines include all lines after ### To Read: except for the line that reads ### Read:. The script below does this and then, to demonstrate success, displays the arrays (using declare):
active=
while read line
do
if [ "$line" = '### To Read:' ]
then
active=1
elif [ "$line" = '### Read:' ]
then
active=1
elif [ "$active" ]
then
IFS='|' my_array=($line)
declare -p my_array
fi
done <mylist
The output from your sample input is:
declare -a my_array='([0]="One Hundred Years of Solitude " [1]=" Gabriel García Márquez")'
declare -a my_array='([0]="Moby-Dick " [1]=" Herman Melville")'
declare -a my_array='([0]="Frankenstein " [1]=" Mary Shelley")'
declare -a my_array='([0]="On the Road " [1]=" Jack Kerouac")'
declare -a my_array='([0]="Eyeless in Gaza " [1]=" Aldous Huxley")'
declare -a my_array='([0]="The Name of the Wind (The Kingkiller Chronicles: Day One) " [1]=" Patrick Rothfuss " [2]=" 6-27-2013")'
declare -a my_array='([0]="The Wise Man’s Fear (The Kingkiller Chronicles: Day Two) " [1]=" Patrick Rothfuss " [2]=" 8-4-2013")'
declare -a my_array='([0]="Vampires in the Lemon Grove " [1]=" Karen Russell " [2]=" 12-25-2013")'
declare -a my_array='([0]="Brave New World " [1]=" Aldous Huxley " [2]=" 2-2014")'
Note that this approach easily handles the input even though the lines have different numbers of fields.

Answer 2

You are not telling us how to deliver the final output, but here is a skeleton for an Awk solution.
awk -F ' \| ' '/^### To read:/ { s=1; next }
/^### Read:/ { s=2; next }
s==1 { print $1 "," $2 ",\"\"" }
s == 2 { print $1 "," $2 "," $3 }' file
This will simply print an empty third field from the first subsection. You can obviously adapt the actions to be anything you like, or rewrite this in Python if you are more familiar with that.