grab_packt: A JavaScript repository from RonanCodes

Grab a book a day for free from Packt Pub, https://www.packtpub.com/packt/offers/free-learning.

1. Install prerequisites

Install this script in the cloned directory using the following command:

npm install

2. Add credentials

Copy the .env file into place with

cp .env.example .env

Or on Windows:

copy .env.example .env

And set your packt email and password.

3. Grab on recurrent basis

Using Node

After that run the script with the following command:

watch -n 5000 --differences node server.js

Using Crontab

Or add it to your crontable:

crontab -e

For the crontab all paths in MUST be absolute.

Within the open cron editor window

0 14 * * * /usr/local/bin/node /Users/<USER_NAME>/<PATH_TO>/grab_packt/server.js >> /tmp/cron_output

Using Task Scheduler in Windows

Check the run.bat file in the repo. Correct any path if necessary according to your needs. Try running the script manually to verify that it works as expected.

Then add a scheduled task to execute run.bat every day by running.

add_scheduled_task.bat

OSX Error

If you get the message: crontab: temp file must be edited in place

On a related issue, if you get the message: crontab: temp file must be edited in place

Try:

Add to .bash_profile

alias crontab="VIM_CRONTAB=true crontab"

Add to .vimrc

if $VIM_CRONTAB == "true"
    set nobackup
    set nowritebackup
endif

note: .bash_profile might be called .profile
note: .vimrc and .bash_profile are located in the home directory: ~/
Reference: http://superuser.com/a/750528

Using Launchd (OSX)

launchd is recommended over cron for the OSX system.

This runs on load and from then on every 24 hours (86400 seconds).
Just substitute <username> for your own.

by daemon I am referring to the .plist file

Navigate to directory:

cd $HOME/Library/LaunchAgents

Create file:

touch com.<username>.grab_pkt.plist

Edit file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.<username>.grab_pkt</string>

  <key>ProgramArguments</key>
  <array>
    <string>/usr/local/bin/node</string>
    <string>/Users/<username>/development/misc/grab_packt/server.js</string>
  </array>

  <key>Nice</key>
  <integer>1</integer>

  <key>StartInterval</key>
  <integer>86400</integer>

  <key>RunAtLoad</key>
  <true/>

  <key>StandardErrorPath</key>
  <string>/tmp/GrabPkt.err</string>

  <key>StandardOutPath</key>
  <string>/tmp/GrabPkt.out</string>
</dict>
</plist>

Load this daemon into the system:

launchctl load com.<username>.grab_pkt.plist

to unload just change load to unload

Check output of script:

/tmp/GrabPkt.out

It should be similar to:

----------- Packt Grab Started -----------
Book Title: Learning Libgdx Game Development
Claim URL: https://www.packtpub.com/freelearning-claim/13277/21478
----------- Packt Grab Done --------------

Check for errors:

/tmp/GrabPkt.err

Mine is empty due to having no errors.

In order to test I would:

remove the GrabPkt.out file
unload daemon
load daemon
check output of GrabPkt.out file

reference: http://alvinalexander.com/mac-os-x/mac-osx-startup-crontab-launchd-jobs

RonanCodes/grab_packt