Shell Programming and Scripting

Hello all,

I've a small script where it checks for the existence of a particular file and sleeps for 5 seconds if it doesn't exist. I would like to send the sleep output to background so that I don't see so many sleep messages in the build output.

Code:

#!/bin/sh -x
until [ -f /tmp/examplefile.txt ]
do
sleep 3
done
echo "File found"

Adding & to the end of the sleep command doesnt work. Any help is much appreciated.

Regards
builderj

Linux has the inotify command to do exactly this. What OS do you have?

RedHat 5 and Redhat 6

Any reason you are using the sh -x option? Try leaving that out.

/usr/bin/sleep does not produce any output.....

@rovf : /usr/bin/sleep did not work. Even tried /bin/sleep.

whereis sleep
sleep: /bin/sleep /usr/share/man/man1p/sleep.1p.gz /usr/share/man/man3p/sleep.3p.gz /usr/share/man/man1/sleep.1.gz /usr/share/man/man3/sleep.3.gz

@Scrutinizer : even after leaving our sh -x, it didn't work.

WHAT "did not work"?

sleep itself does NOT produce any output, as rovf correctly stated. And, as Scrutinizer said, leaving out the -x option will stop xtrace output (which, btw, would go to stderr anyway).
If you are talking of the loop just keeps looping frantically, that's because you put sleep into background, peacefully sleeping there, side by side, while the main loop continues and continues and ...