Run a Program in the Background with nohup on Ubuntu Gnome 15.04

This is post is how to run a program from the terminal in the background so that it will continue to run even when the terminal window is closed. I use the nohup command to accomplish this. I have a server that I log into with ssh. I run a rysnc backup command to that copies data to a usb3, 2 GB external hard drive.  This can take several hours to complete. Sometimes I need to close my ssh session, for example to reboot my client computer, yet I don’t want the backup to stop. I am running linux, Ubuntu Gnome 15.04 and all commands are run from the terminal.

Example of no hup command

nohup nice -n20 bkup.offsite.cc.com.py > /dev/null 2>&1 &

I will break down what is happening.

nohup – prevents the commands following from stopping if the terminal window is closed

nice -n20 – runs the program bkup.offsite.cc.com.py at a lower priority for cpu resources to prevent other programs on the computer from slowing down

bkup.offsite.cc.com.py – the python backup program to execute

> /dev/null 2>&1 – This does not show error messages and output, nohup normally writes standard output to a file nohup.txt. When my output was written to nohup.txt, the file size was 1.2 GB!

& – puts the command in the background so that you can use the terminal for other tasks

To see the status of your running application run the following command:

jobs

Output will be:

[1]+  Running   nohup nice -n20 bkup.offsite.cc.com.py &

A good reference for working with jobs: http://linuxcommand.org/lc3_lts0100.php

Reference: http://unix.stackexchange.com/questions/32574/when-do-you-need-nohup-if-youre-already-forking-using?lq=1

Add Owncloud Clients to Iphone IOS and OSX Yosemite

Iphone IOS

Click on this link, http://itunes.apple.com/us/app/owncloud/id543672169?ls=1&mt=8, to open the owncloud client in the App Store. Download and instructions are here https://owncloud.com/products/mobileapps/.

Mac Laptop or Desktop running OSX Yosemite

Click on the following link to install the software https://owncloud.com/download#desktop-clients.

Download and instructions here https://owncloud.com/products/desktop-clients/. “Simply copy a file into the directory and the ownCloud desktop client does the rest. Make a change to the files on one computer, it will flow across the others using these desktop sync clients. Always have your latest files with you wherever you are.”

 

How to See Information about a Installed Debian Package

I needed to see what version of mythtv was installed on my Ubuntu 14.04 server and what dependencies it requires. Here is the solution.

.deb packages are stored at /var/cache/apt/archives

View mythtv package name

#ls -l /var/cache/apt/archives/mythtv*
mythtv_2%3a0.27.4+fixes.20150514.6b73976-0ubuntu0mythbuntu4_all.deb

Display Package Version

# apt-show-versions mythtv
mythtv:all/trusty 2:0.27.4+fixes.20150514.6b73976-0ubuntu0mythbuntu4 uptodate

Reference: http://unix.stackexchange.com/questions/6284/check-package-version-using-apt-get-aptitude

Display Package Information

#dpkg -I mythtv_2%3a0.27.4+fixes.20150514.6b73976-0ubuntu0mythbuntu4_all.deb

new debian package, version 2.0.
size 78060 bytes: control archive=1084 bytes.
1449 bytes, 34 lines control
209 bytes, 3 lines md5sums
Package: mythtv
Version: 2:0.27.4+fixes.20150514.6b73976-0ubuntu0mythbuntu4
Architecture: all
Maintainer: MythTV Ubuntu Maintainers <ubuntu-mythtv@lists.ubuntu.com>
Installed-Size: 101
Depends: mysql-server | mysql-server-5.6, mythtv-database, mythtv-frontend, mythtv-backend, ntp | time-daemon | ntp-simple
Suggests: mythtv-doc
Section: graphics
Priority: optional
Homepage: http://www.mythtv.org
Description: Personal video recorder application (client and server)
MythTV implements the following PVR features, and more, with a
unified graphical interface:
.
- Basic 'live-tv' functionality. Pause/Fast Forward/Rewind "live" TV.
- Video compression using RTjpeg or MPEG-4
- Program listing retrieval using XMLTV
- Themable, semi-transparent on-screen display
- Electronic program guide
- Scheduled recording of TV programs
- Resolution of conflicts between scheduled recordings
- Basic video editing
.
http://www.mythtv.org/
.
This package will install a complete MythTV client/server environment on a
single system. If you are intended on using this as your only MythTV machine,
and this machine is already configured as a desktop, this package will get you
up and running switfly.
.
If you are intended on installing this on a standalone/non-desktop machine,
you should look into the metapackages available:
mythtv-backend-master (backend with a local database)
mythtv-backend (backend needing a remote database)

Reference: http://askubuntu.com/questions/80655/how-can-i-check-dependency-list-for-a-deb-package

2015-05-14