Success!!!
Must be my lucky day because I really don't know what the heck I'm doing.
After reading your last post, I manually inserted the lines from the patch into the source files from rockbox-21704.
I searched for text similar to that referenced in what I guess must be the patch insertion point definition. Then I copied the lines from the patch that begin with + into those locations.
I then compiled and installed the resulting build and added "auto shutdown: 3" to the config file. Upon reboot the sleep timer was set to 3 minutes and proceeded to countdown. Other values also work. I did notice that the timer goes negative before the shutdown actually occurs. The negative timer count is not unique to my build.
If you enter "auto shutdown: 0" into the config file the sleep timer does not set on start-up but rockbox removes the line from the file. What's up with that??
This patch does exactly what I wanted since I usually turn the E200 on at bedtime.
If I want to use it at other times it is simple enough to turn the sleep timer off after I start the player.
It would be nice to be able to set/enable/disable the auto shutdown in the Rockbox settings menu.
I have managed a workaround by creating multiple config files.
"auto shutdown: ###" is the only line in them. I load the config file with the amount of time I want in the sleep timer and then save the current configuration to "config.cfg" When player is restarted the sleep timer is set.
To disable auto shutdown I load a config file that contains "auto shutdown: 0" and save the current configuration to "config.cfg" When player is restarted auto shutdown is removed from the config file and sleep timer is not set.
If I can figure out how to correct the original patch so it will apply to current code is there much of a chance of getting it committed?
Thank you very much for your help.