help with while loop

Shell Programming and Scripting
1

Hi,

I'm trying to write a while loop that will search for "[JkMain] Jk running" in temp.out file
if the word is not there then I want to keep looping until it's there then I want to exit the loop.
I'm not sure what to do please help.
Thank you.

Here is what I have so far.

while check=`grep "*[JkMain] Jk running" | wc -l`
do

if [ $check -gt 0 ]
then
	echo " Jk running is in temp.out"
	exit
fi

done < nohup.out

2 
until fgrep "[JkMain] Jk running" temp.out >/dev/null&&\
    echo "Jk running is in temp.out"; do         
    sleep 10 
done
3

radoulov,

This might be a silly question but why are we sending it to dev/null?

4

Otherwise you'll get the matched pattern on the screen (assuming your grep doesn't support the q option):

$ until fgrep "[JkMain] Jk running" temp.out >/dev/null&&\
> echo "Jk running is in temp.out"; do
> sleep 1
> done
Jk running is in temp.out
$ until fgrep "[JkMain] Jk running" temp.out&&\
> echo "Jk running is in temp.out"; do
> sleep 1
> done
[JkMain] Jk running
Jk running is in temp.out

If you're on Linux or Solaris (using grep under /usr/xpg4/bin) you could avoid the redirect:

$ alias grep=/usr/xpg4/bin/grep
$ until grep -Fq "[JkMain] Jk running" temp.out&&\
> echo "Jk running is in temp.out"; do
> sleep 1
> done
Jk running is in temp.out
5

Thank you.