I'm writing a short script for a slideshow using fbi. For sake of completeness, the script gets executed after an automatic login on an Ubuntu machine, which should run headless; the machine only external interface should be a Samba folder where I add/remove images.
I started easy:
usr/bin/fbi -noverbose -a -t 4 -u `find -type f | egrep -i "(jpg|bmp|png|gif)$"`
This works fine: find/egrep return a list of files that fbi shows at 4 seconds interval.
Now, I need to refresh my slide list when a new image gets added or an existing one gets deleted. I tried watch, without success.
If I execute from command line this:
watch -n 300 -t `find -type f | egrep -i "(jpg|bmp|png|gif)$"`
I get the same list of files and whenever I add an image to my target folder, the list gets updated within next 5 minutes. Fine. But when I add this to my script, nothing works:
/usr/bin/fbi -noverbose -a -t 4 -u `watch -n 300 -t 'find -type f | egrep -i "(jpg|bmp|png|gif)$"'`
With this, I get nothing and when I interrupt the slideshow, my command line is screwed (no carriage return, no typing echo...).
What am I doing wrong/overlooking/missing? Or am I completely off target?
Because another solution would be to have two scripts, the slideshow's one and a controller script (maybe using inotify-tools), killing and restarting the slideshow script when target folder gets modified.
Any suggestion or tip, veeeery appreciated!
rash*
watch -n 300 -t `find -type f | egrep -i "(jpg|bmp|png|gif)$"`
What this is doing, because you've used backticks, is passing the list of filenames to watch, which I suspect you don't want to do. Maybe this would work, but I don't have any way to test:
watch -n 300 -t '/usr/bin/fbi -noverbose -a -t 4 -u `find -type f | egrep -i "(jpg|bmp|png|gif)$"`'
Though this brings up the thorny question of just how many copies of fbi will be running after a few days.
Probably your best bet would be to set up a cron job to run a script like this every x minutes:
#!/bin/bash
pkill -f /usr/bin/fbi
shopt globstar
cd /your/images/directory
files=(**/*.jpg **/*.bmp **/*.png **/*.gif)
usr/bin/fbi -noverbose -a -t 4 -u "${files[@]}"
Instead of using find and grep, I used bash globbing, which is safe for filenames with spaces, and also saves you running two other commands! This requires bash 4+ for the globstar option that provides recursive matching.
The globbing gives you file names in an array, which is passed directly to fbi, as described in Bash FAQ 50