UNIX for Dummies Questions & Answers

Am sorry,
what is the need for 2 pipes
and where do you count the number of instances ?

Logical OR.

You don't need it when checking $count == 0 ...

Thanks all for the care in replying me with your solution.

Below is the code which is available in shell script.

Code:

CLASSPATH=.
CLASSPATH=${CLASSPATH}:sampleswing.jar
nohup java -cp ${CLASSPATH} Sample > /dev/null 2>&1 &
echo "kill -9 "$! > killer.sh
chmod 777 killer.sh

For example when executed, It creates a process named "java" with some unique process ID.before starting this process, there may be other java programs which may be running or any system related java process with name "java" may be running.

If that is the case, i cannot distingush between my java process "java" and other java process which has got same process name as "java"

Reply wud be very much appreciated

If grep fails, then java gets called. grep fails when it does not find any instance.

Probably this will make it simpler to understand.

Code:

[ -f /tmp/java ] && echo "Found" || echo "Not found"

It goes along the lines of the if-else construct.

$! contains the pid you're asking for and you're already using it in the "kill -9"$! command.

seems to be right solution for my second requirement.
tell me how can we suppress the output like
I want only the output of "echo command" to be known and so that i can perform some check like ,if there is a value being returned ..it implies me ..Process is not running....

Can u shed some light on it ..i am new to unix

Code:

ps -p $! >&- || echo "not running"

If the above doesn't work use:

Code:

ps -p $! >/dev/null||echo "not running"