Using 'find' to send multiple child processes to the bg

[spex]

Hello everyone,

I'm using sh-posix under B.11.11.

I'm trying to come up with a find construct to send multiple child processes to the bg. This will be used for parallel backup of datafiles located anywhere within a directory structure.

Here's what I've tried so far as a test:
# find /u02/oradata/mysid -name '*.dbf' -type f -exec sh -c "sleep 60 &" \;

# ps -f | grep sleep
shows that one sub-process running 'sleep' exists for each .dbf file. So far so good. However, when I try to pass the current path name to -exec, I get the following:
# find /u02/oradata/mysid -name '*.dbf' -type f -exec sh -c "ll {} &" \;
{} not found
{} not found
{} not found
{} not found
{} not found
{} not found

Note that I've tried to accomplish the same thing with '-exec &' (instead of 'sh -c " &"') and 'find ... | xargs -i ' with no luck.

Ultimately, I would like to copy all .dbf files within a directory structure in parallel, 'wait' for all the child processes to terminate, and then repeat for a new directory structure.

If anyone has any suggestions, I would appreciate reading them.

Thanks,

PCS

[Steven E. Protter]

Shalom,

If this is being done to make things copy faster or involves large files, its likely to work more slowly than a sequential file copy. Head thrashing will probably occur.

Try enclosing the current path in quotes so teh special characters don't confuse find.

SEP

[Pete Randall · Accepted solution]

What about a for loop instead?

for FILE in `find /u02/oradata/mysid -name '*.dbf' -type f`
do
your_desired_command
done

I haven't tested but I think that accomplishes your goal.


Pete

[spex]

Steven,

With this particular server/storage combination, it is definitely faster to copy files in parallel.

Pete,

Of course! I was so intent on doing everything within 'find' that I didn't think of using an external loop. Thanks for your insight.

PCS

[Dennis Handly]

If you have too many files for an external for loop, have -exec invoke a script then invokes the real script with "&".

>Pete:for FILE in `find /u02/oradata/mysid -name '*.dbf' -type f`; do

You do know you should replace `` by $()?
for FILE in $(find /u02/oradata/mysid -name '*.dbf' -type f); do

[Pete Randall]

Dennis,

I *SHOULD*??? When the Posix police come around and insist that I change not only my ingrained habits, but all my old scripts, and indicate that they're willing to pay for all this effort, I'll *THINK* about it.


Pete