Shell Programming and Scripting

I'm not at all sure that I understand what you're trying to do, but note that the each of the background subshells started by:

Code:

    (
    printf "%-29s " "$userhost"
    ssh -nx -o BatchMode=yes "$userhost" 'lsb_release -sd'
    ) </dev/null >"$tmpdir/$userhost" 2>&1 &

writes to a different file for each host. If you want all of the output in a single file and you want to trim off the first part of the lsb_release output you need something more like:

Code:

    (
    release=$(ssh -nx -o BatchMode=yes "$userhost" 'lsb_release -sd')
    printf "%-29s %s\n" "$userhost" "Rel${release##*Rel}"
    ) </dev/null >>"$tmpdir/alluserhosts" 2>&1 &

clearing the output file before you start your loop with:

Code:

>"$tmpdir/alluserhosts"

unless you want the output in that file to grow each time you invoke your script.

Since I don't have access to a system with lsb_release installed, the above is totally untested. But, in theory, it should come close to what you seem to want.

Hmm I think asynchronous background jobs MUST go to separate logs.
Otherwise they might overwrite each other, and the shared log file becomes a mess.

Note that in the code I suggested in post #8, the output to the single log file is produced by a single invocation of the printf utility that uses an append redirection operator (>>) instead of the overwrite redirection operator (>) that was in the original code. Although not required by the standards, I would expect the output of that invocation of printf to be produced by a single write() system call, which, when writing the amount of data shown in the examples to a regular file, should be an atomic operation. Using the append redirection should prevent the concurrent background processes from overwriting each other's output and the single printf instead of multiple echos should keep the output from the various background processes from being intermixed.