cron question

[shantiq]

starting to use cron

using this guide here (http://www.scrounge.org/linux/cron.html)

so i have my file called mousepad.cron


which contains this line


0,3,6,9,12,15 **** /usr/bin/mousepad


just for testing :KS


then i run


crontab mousepad.cron



and get this



new crontab file is missing newline before EOF, can't install.






what does this mean?

[Lisiano]

EOF - End Of File. Seems it just wants you to make a newline right after /usr/bin/mousepad.
Btw. You can always just edit your own crontab instead of making a new one. Just type crontab -e. Before that you need to export a editor you wish to use to edit cron. For example nano.
export EDITOR=nano
crontab -e

EDIT: To make it permanent you can always add it to the end of your ~/.bashrc

echo "export EDITOR=nano" >> ~/.bashrc
Don't accidentally type a single > . Or else you will overwrite your .bashrc to contain only that line. You can get a copy of the old one from /etc/skel/.bashrc if you do overwrite it.

[papibe]

Not related to your error, but I think this (https://help.ubuntu.com/community/CronHowto) community guide is very good.

Regards.

[shantiq]

thanx for replies Lisiano it may seem a dumb question but how to do that


EOF - End Of File. Seems it just wants you to make a newline right after /usr/bin/mousepad.
what have i got to change to



0,3,6,9,12,15 **** /usr/bin/mousepad



to do that sorry i do not understand :KS



ok got it

just hit return before saving

[shantiq]

ok next question :KS


if i enter


1 20 * * * /usr/bin/gnome-text-editor

gnome-text-editor should open at 20:01 right


but it does not


what am i not seeing? what could possibly be wrong?

[papibe]

Cron runs in a very limited environment. In order to open graphical applications you need to set the 'display' variable. Check the section 'GUI Applications' on the guide that I linked in my previous post.

Regards.

[shantiq]

thank you papibe for pointers will investigate


ok and with all your help guys finally got there


This will record a World Music Program on Radio 3 in 320kbps every sunday at 22:00 for an hour every week every month; which is what i wanted to do in the first place. so thank you.


0 22 * * 0 get_iplayer --get --force --type=liveradio --stop 3600 "http://www.bbc.co.uk/mediaselector/4/gtis/?server=cp60703.live.edgefcs.net&identifier=Special_Event1_UK@s6485&kind=akamai&application=live" && sudo shutdown -h +15

with shutdown set so it does not require a password


sudo gedit /etc/sudoers

and add


#includedir /etc/sudoers.d
username ALL=NOPASSWD: /sbin/shutdown

at bottom of file then save

[Lisiano]

I recommend you use
shutdown -h now instead. You can use
sudo crontab -e to add a entry as root and point to do
0 23 * * 0 shutdown -h now or
0 22 * * 0 shutdown -h 23:00
Also you shouldn't edit /etc/sudoers manually. Use this instead
sudo visudo
(The EDITOR variable also makes you use nano here instead of vi)

[shantiq]

hi again Lisiano 2 questions

=======================
I have heard this before




Also you shouldn't edit /etc/sudoers manually. Use this instead
Code:
sudo visudo



could you please explain why not and why it is better to use visudo i found its layout confusing why i chose gedit instead or even mousepad what is the difference?

==================

also


is
shutdown -h now different from
sudo halt and how exactly?


Thanx for all info

[Lisiano]

visudo does a syntax check so your edits don't break sudo, since it obeys the EDITOR varibale you can export nano, gedit or mousepad and make edits with them but I don't know if using graphical applications work well as EDITOR variables.
As for shutdown against halt. As you noticed you can specify when to turn off the PC, while halt was modified to call shutdown instead (I think), it's better to call shutdown directly for the added functionality of being less brutal and letting users know that the system will turn off in N minutes. Also to scare users with the -k switch ('Fake' shutdown). You can actually cancel a shutdown if for example you are doing something and remember that you still need to do stuff, you can issue a
shutdown -c and continue working without interruptions.
Also adding either one of those in the root crontab let's you use both of them without sudo. While under normal circumstances you need to call sudo either way. Also having them in the root crontab instead of being "sudo usable without a pass by anyone" makes sure that the system can be turned off only by using sudo AND a password or waiting (in your case) until it's 23:00.

[shantiq]

thank you Lisiano for very helpful clarifications ):P