sequential running for 2 scripts

Shell Programming and Scripting
1

Hello

I have a script that has 2 scripts that must be executed one after the other.
however, when I run the script, the 2 sub-scripts are run in parallel.

any idea how to fix this without using sleep command?

thank you

2

use locks .... simple solution is use wait ......using pid of process

3

Have script one create a file "script1running" when it starts, and delete it when done.

Embed some kind of wait or delay to make sure script one got a chance to create that locking file.
Then have script two in a loop checking for the existence if "script1running". Once the file does not exist, then script two can continue.

4

Hi

Currently I am using this:

Fct1()
{
touch /tmp/lock$$
...
rm /tmp/lock$$
}
Fct2()
{
while [ -f /tmp/lock$$ ]
do
sleep 30
done
...
}

Is there a better way to synchronize? (I still need to test the above solution )

thank you.

5

hi

can you please help in this?

thanks

6

Checking the lock and creating the lock should be done as a single atomic operation, otherwise after the lock is not found and before it is created a concurrent process could also see no lock and decide to go on.

This is one way to do the check and the creation atomically:

until mkdir /tmp/lockdir 2>/dev/null; do
  sleep 1
done

The problem with mkdir is that if the script is aborted then a fictitous lock is left behind.
With trap you can provide a handler to remove the lock for any termination reason, but a SIGKILL cannot be trapped.

7

Hi Joyeg,

are you suggesting something like this-

#!/usr/bin/ksh
echo "this is a script that runs two script one after the other"
./dateformat.sh > script1running; wait 5 ; rm -f script1running;
for file in *;do
if [ $file = "script1running" ]
 then
   echo "the script1running file is there"
  else
   ./sample.sh
   break
  fi
   done

Thanks
NT

8

I tried another approach

fct1
while [ ! -f $ORACLEHOME/root.sh ]
do
sleep 200
done
fct2

still fct2 runs without waiting for fct1 to end