Extract information between double quotes on .csv

Question

I'm having some problems with a script parsing a .csv file

Information on .csv:

#1,13/8/2020,[email protected],[email protected],,Subject,"Dear Dude,

Information have been updated. Please login to APP to review by 30th August 2020. Thank you.

Best regards,
Mr. Mack",Pending,13/8/2020 12:35

This is how information should be partioned: MsgID,Date,To,CC,BCC,Subject,Body,Status,Timestamp

MsgID=#1
Date=13/8/2020
[email protected]
[email protected]
BCC=
Subject=Subject
Body=Dear Dude,
Information have been updated. Please login to APP to review by 30th August 2020. Thank you.
Best regards,
Mr. Mack
Status=Pending
Timestamp=13/8/2020 12:35

The problems I'm having are with the body part for two reasons, the "," in the text that breaks when I'm trying to run the script and the other reason is the line breaks in the text.

This is the script that I was doing:

#!/bin/bash

export TIMESTAMP="$( date '+%d/%m/%Y %H:%M:%S' )"
INPUT=/tmp/test.csv
OUTPUT=/tmp/test.csv.out
OLDIFS=$IFS
IFS=','
[ ! -f $INPUT ] && { echo "$INPUT file not found"; exit 99; }
while read msgid dat to cc bcc subject body status timesta
do
        echo "MSG ID : $msgid" 
        echo "Date : $dat"
        echo "To : $to"
        echo "CC : $cc"
        echo "BCC : $bcc"
        echo "Subject : $subject"
        echo "Body : $body"
        echo "Status : $status"
        echo "Timestamp : $timesta"
echo $body | mail -s "$subject" $to -c $cc -b $bcc
printf "$msgid,$dat,$to,$cc,$bcc,$subject,$body,Sent,$TIMESTAMP" >> $OUTPUT
done < $INPUT
IFS=$OLDIFS

Answer 1

The shell is just a very bad tool for text parsing. You should only use it for the most simple of tasks, and probably not even then. It is slow, inefficient, its very complicated syntax makes it error prone and it lacks the most basic text processing tools. On top of this, CSV is a complex format that allows nested and multi-line entries. Trying to parse a CSV file in the shell is just asking for trouble.

So, use a proper programming language with support for CSV parsing instead. For example, in python:

#!/bin/python3
import csv
import sys

with open(sys.argv[1], newline='') as csvfile:
    fieldnames = ("MsgID","Date","To","CC","BCC",
                  "Subject","Body","Status","Timestamp")
    reader = csv.reader(csvfile, delimiter=',',
    for row in reader:
        for fieldName, value in zip(fieldnames,row):
            print("%s: %s" % (fieldName,value))

I saved the script above as foo.py and then:

MsgID: #1
Date: 13/8/2020
To: [email protected]
CC: [email protected]
BCC: 
Subject: Subject
Body: Dear Dude,

Information have been updated. Please login to APP to review by 30th August 2020. Thank you.

Best regards,
Mr. Mack
Status: Pending
Timestamp: 13/8/2020 12:35

As you can see, it has correctly recognized all fields. So, in order to also send the mail, you could do something like this (adapted from here):

#!/bin/python3
import csv
import sys
import subprocess
import os

def send_message(to, cc, bcc, subject, body):
    try:
        process = subprocess.Popen(['mail', '-s', subject, '-c', cc, '-b', bcc, to],
                                   stdin=subprocess.PIPE)
    except Exception as error:
      print(error)
    process.communicate(body)


with open(sys.argv[1], newline='') as csvfile:
    reader = csv.reader(csvfile, delimiter=',')
    for row in reader:
        (msgID, date, to, cc, bcc, subj, body, status, timestamp) = row
        send_message(to, cc, bcc, subj, body)

DISCLAIMER: You seem to be using BSD mail based on the options you have. I don't have access to a working system with that tool installed so I could not test the mail sending script above. It should at least serve as a good start though.

Answer 2

You could use a tool as Miller (https://github.com/johnkerl/miller), specialized to work on structured text data.

In example starting from this input.txt file

#1,13/8/2020,[email protected],[email protected],,Subject,"Dear Dude,

Information have been updated. Please login to APP to review by 30th August 2020. Thank you.

Best regards,
Mr. Mack",Pending,13/8/2020 12:35

and running

mlr --implicit-csv-header --c2x cat then label MsgID,Date,To,CC,BCC,Subject,Body,Status,Timestamp input.txt

you will have

MsgID     #1
Date      13/8/2020
To        [email protected]
CC        [email protected]
BCC
Subject   Subject
Body      Dear Dude,

Information have been updated. Please login to APP to review by 30th August 2020. Thank you.

Best regards,
Mr. Mack
Status    Pending
Timestamp 13/8/2020 12:35

If you want to remove carriage return in body field, you can run

mlr --implicit-csv-header --c2x cat then label MsgID,Date,To,CC,BCC,Subject,Body,Status,Timestamp then put '$Body=gsub($Body,"\n"," ")' input.txt

to have

MsgID     #1
Date      13/8/2020
To        [email protected]
CC        [email protected]
BCC
Subject   Subject
Body      Dear Dude,  Information have been updated. Please login to APP to review by 30th August 2020. Thank you.  Best regards, Mr. Mack
Status    Pending
Timestamp 13/8/2020 12:35