WebOS Internals - User contributions [en]

Application talk:Govnah

2010-05-04T23:09:29Z

Irwinr: New page: Question: Does the 'governor' select in Govnah (IE: Screenstate for example) keep governing the CPU even after 'Govnah' is closed? --irwinr

Question: Does the 'governor' select in Govnah (IE: Screenstate for example) keep governing the CPU even after 'Govnah' is closed? --irwinr

Talk:Uber Calendar

2010-05-04T22:59:29Z

Irwinr: New page: So what exactly does this do?

So what exactly does this do?

Talk:Colorful Bash Prompt

2010-02-21T15:26:04Z

Irwinr: New section: Read only file system

--[[User:Cooknn|Cooknn]] 15:05, 21 February 2010 (UTC) Even though I'm root I get "read only filesystem" when I try to create /etc/bash or even modify /etc/profile. Suggestion would be greatly appreciated!

== Read only file system ==

The file system on the WebOS is *mounted* read-only, so no process (superuser or not) may modify the file system.

To make changes, you have to 'remount' the file system in read-write mode:

mount -o rw,remount /

This command must be run as with sudo (or as root).

Crond

2009-08-24T15:26:54Z

Irwinr: /* Alternative (ipkg-opt) Method */

== Enabling Stock Cron==

The [[Patch webOS GPS Tracking]] guide had a nice bit about enabling crond on the Pre. It looks like its already pre-installed, just not set up to start. You will need to edit /etc/event.d/mod-crond (don't modify the existing crond startup-script) to enable cron to start. The settings should look like this:

<pre><nowiki>
# -*- mode: conf; -*-

# jobfile for busybox crond, with pre-start commands to create the
# directory and files it wants by default. That there's not 'start
# on' stanza is intentional: it's for development use only. We can
# turn it on later if we need it, e.g. to keep the clock synced. It
# does work.

start on stopped configure
stop on started start_update

respawn

exec /usr/sbin/crond -f -L /var/log/crond

pre-start script
mkdir -p /var/spool/cron/crontabs
ln -sf /etc/cron/crontabs/root /var/spool/cron/crontabs/root
end script
</nowiki></pre>

A few notes here. Unlike the Dropbear and other scripts I make my upstart scripts so that essential services don't stop when the device exists runlevel 2. This seems to shutdown these services whenever the device locks. I prefer that my upstart services stop only when the updater runs. Also I have made cron log to a separate file under /var/log so that it can be monitored better.

One thing to note about the standard script for cron on the Pre is that the /var/spool/cron/crontabs directory is created every time the process runs and a symlink to /etc/cron/crontabs/root is created. To my surprise this file does not exist. So we need to create it:

<pre><nowiki>
sudo mkdir -p /etc/cron/crontabs
sudo sh -c 'echo > /etc/cron/crontabs/root'
</nowiki></pre>

Now to start up crond:

<pre><nowiki>sudo -i initctl start crond</nowiki></pre>

*Note for clarification: I attempted this and it all works OK, but I can't figure out how to actually schedule jobs. I modified /etc/cron/crontabs/root, but nothing seems to happen. I also tried crontab -e, and that doesn't seem to do anything either. I suggest adding a note here clarifying what needs to be done to actually add a cron job. -irwinr

==Alternative (ipkg-opt) Method==

* Another request for clarification: It's not clear which of these two methods are preferred. This method appears to not work when the screen is off (rendering cron pretty useless), the above method appears to delete the cron entries every time the cron daemon starts. Has anyone worked out either of these issues? -irwinr.

crond is a system that allows command to be run at specified intervals.

Do not use the built in crontab -e as it is overwritten on each boot.

Optware has cron available as an installable package, and using /opt/etc/cron.d/ for cron files will not conflict with any Palm files.

<pre><nowiki>
sudo -i
mount -o remount,rw /
ipkg-opt update
ipkg-opt install cron
/opt/bin/crontab -e
# Add script and intervals here
mount -o remount,ro /
</nowiki></pre>

This does not seem to work when the phone's screen turns off. I tried it plugged in for two minutes then unplugged, and turned the screen off for two minutes. I ran
<pre><nowiki>echo `date` >> sleep.log</nowiki></pre>

And got...

<pre><nowiki>
# cat sleep.log
Wed Jul 1 18:27:01 CDT 2009
Wed Jul 1 18:28:01 CDT 2009
Wed Jul 1 18:30:16 CDT 2009 ## Turned the screen back on. It seems to play catch up.
Wed Jul 1 18:30:16 CDT 2009
</nowiki></pre>

Crond

2009-08-24T15:26:16Z

Irwinr: /* Alternative (ipkg-opt) Method */

== Enabling Stock Cron==

The [[Patch webOS GPS Tracking]] guide had a nice bit about enabling crond on the Pre. It looks like its already pre-installed, just not set up to start. You will need to edit /etc/event.d/mod-crond (don't modify the existing crond startup-script) to enable cron to start. The settings should look like this:

<pre><nowiki>
# -*- mode: conf; -*-

# jobfile for busybox crond, with pre-start commands to create the
# directory and files it wants by default. That there's not 'start
# on' stanza is intentional: it's for development use only. We can
# turn it on later if we need it, e.g. to keep the clock synced. It
# does work.

start on stopped configure
stop on started start_update

respawn

exec /usr/sbin/crond -f -L /var/log/crond

pre-start script
mkdir -p /var/spool/cron/crontabs
ln -sf /etc/cron/crontabs/root /var/spool/cron/crontabs/root
end script
</nowiki></pre>

A few notes here. Unlike the Dropbear and other scripts I make my upstart scripts so that essential services don't stop when the device exists runlevel 2. This seems to shutdown these services whenever the device locks. I prefer that my upstart services stop only when the updater runs. Also I have made cron log to a separate file under /var/log so that it can be monitored better.

One thing to note about the standard script for cron on the Pre is that the /var/spool/cron/crontabs directory is created every time the process runs and a symlink to /etc/cron/crontabs/root is created. To my surprise this file does not exist. So we need to create it:

<pre><nowiki>
sudo mkdir -p /etc/cron/crontabs
sudo sh -c 'echo > /etc/cron/crontabs/root'
</nowiki></pre>

Now to start up crond:

<pre><nowiki>sudo -i initctl start crond</nowiki></pre>

*Note for clarification: I attempted this and it all works OK, but I can't figure out how to actually schedule jobs. I modified /etc/cron/crontabs/root, but nothing seems to happen. I also tried crontab -e, and that doesn't seem to do anything either. I suggest adding a note here clarifying what needs to be done to actually add a cron job. -irwinr

==Alternative (ipkg-opt) Method==

Request for clarification: It's not clear which of these two methods are preferred. This method appears to not work when the screen is off (rendering cron pretty useless), the above method appears to delete the cron entries every time the cron daemon starts. Has anyone worked out either of these issues? -irwinr.

crond is a system that allows command to be run at specified intervals.

Do not use the built in crontab -e as it is overwritten on each boot.

Optware has cron available as an installable package, and using /opt/etc/cron.d/ for cron files will not conflict with any Palm files.

<pre><nowiki>
sudo -i
mount -o remount,rw /
ipkg-opt update
ipkg-opt install cron
/opt/bin/crontab -e
# Add script and intervals here
mount -o remount,ro /
</nowiki></pre>

This does not seem to work when the phone's screen turns off. I tried it plugged in for two minutes then unplugged, and turned the screen off for two minutes. I ran
<pre><nowiki>echo `date` >> sleep.log</nowiki></pre>

And got...

<pre><nowiki>
# cat sleep.log
Wed Jul 1 18:27:01 CDT 2009
Wed Jul 1 18:28:01 CDT 2009
Wed Jul 1 18:30:16 CDT 2009 ## Turned the screen back on. It seems to play catch up.
Wed Jul 1 18:30:16 CDT 2009
</nowiki></pre>

Crond

2009-08-19T22:56:35Z

Irwinr:

== Enabling Stock Cron==

The [[Patch webOS GPS Tracking]] guide had a nice bit about enabling crond on the Pre. It looks like its already pre-installed, just not set up to start. You will need to edit /etc/event.d/mod-crond (don't modify the existing crond startup-script) to enable cron to start. The settings should look like this:

<pre><nowiki>
# -*- mode: conf; -*-

# jobfile for busybox crond, with pre-start commands to create the
# directory and files it wants by default. That there's not 'start
# on' stanza is intentional: it's for development use only. We can
# turn it on later if we need it, e.g. to keep the clock synced. It
# does work.

start on stopped configure
stop on started start_update

respawn

exec /usr/sbin/crond -f -L /var/log/crond

pre-start script
mkdir -p /var/spool/cron/crontabs
ln -sf /etc/cron/crontabs/root /var/spool/cron/crontabs/root
end script
</nowiki></pre>

A few notes here. Unlike the Dropbear and other scripts I make my upstart scripts so that essential services don't stop when the device exists runlevel 2. This seems to shutdown these services whenever the device locks. I prefer that my upstart services stop only when the updater runs. Also I have made cron log to a separate file under /var/log so that it can be monitored better.

One thing to note about the standard script for cron on the Pre is that the /var/spool/cron/crontabs directory is created every time the process runs and a symlink to /etc/cron/crontabs/root is created. To my surprise this file does not exist. So we need to create it:

<pre><nowiki>
sudo mkdir -p /etc/cron/crontabs
sudo sh -c 'echo > /etc/cron/crontabs/root'
</nowiki></pre>

Now to start up crond:

<pre><nowiki>sudo -i initctl start crond</nowiki></pre>

*Note for clarification: I attempted this and it all works OK, but I can't figure out how to actually schedule jobs. I modified /etc/cron/crontabs/root, but nothing seems to happen. I also tried crontab -e, and that doesn't seem to do anything either. I suggest adding a note here clarifying what needs to be done to actually add a cron job. -irwinr

==Alternative (ipkg-opt) Method==

crond is a system that allows command to be run at specified intervals.

Do not use the built in crontab -e as it is overwritten on each boot.

Optware has cron available as an installable package, and using /opt/etc/cron.d/ for cron files will not conflict with any Palm files.

<pre><nowiki>
sudo -i
mount -o remount,rw /
ipkg-opt update
ipkg-opt install cron
/opt/bin/crontab -e
# Add script and intervals here
mount -o remount,ro /
</nowiki></pre>

This does not seam to work when the phone's screen turns off.
I tried it plugged in for 2 min then unplugged and turned the screen off for 2 min,*/1 * * * echo `date` >> sleep.log and got:
<pre><nowiki>
# cat sleep.log
Wed Jul 1 18:27:01 CDT 2009
Wed Jul 1 18:28:01 CDT 2009
Wed Jul 1 18:30:16 CDT 2009 ## this is when i turned the screen back on, seams to play catch up
Wed Jul 1 18:30:16 CDT 2009
</nowiki></pre>