Script for directory mirroring with inotifywait and ssh

Question

I have a script that try to mirror a specific directory from a local server to a remote one. It looks like that:

inotifywait -mr --format '%w%f' -e close_write -e moved_to -e delete /mydir | \
while read FILECHANGE
do
    if [ -f $FILECHANGE ]
    then
        rsync --bwlimit=4096 --progress --relative -vrae 'ssh -p 22' $FILECHANGE $REMOTEHOST:/
    else
        ssh -p 22 $REMOTEHOST "rm $FILECHANGE"
    fi
done

In case of multiple create of files, as for example a touch command: touch 1 2 3 The 3 files are well transfered.

But if I delete several files at once: rm -f 1 2 3 Only the first 1 is deleted.

If I replace the ssh command by just an echo $FILECHANGE, the 3 files are well displayed in the console. So it seems the problem come from the ssh command, but I can't explain why and solve it.

Anyone as an idea?

It does not answer your question but do you know that rsync can also delete files at destination if they do not exist at source? — Renaud Pacalet, Sep 16 '15 at 09:36
Yes, with the --delete option, if you apply rsync on a directory, I know. But here, I want to apply rsync on a single file. In such a case, if the file does not exist on the origin, rsync exit on an error without doing anything. — Raoul Debaze, Sep 16 '15 at 09:44

score 0 · Accepted Answer · edited Apr 12 '17 at 18:05

Well, I found the issue: it seems that the ssh command was eating the output of the inotifywait command when run. So, to prevent that, I add the 0<&- redirection after the ssh, to close the stdin.

inotifywait -mr --format '%w%f' -e close_write -e moved_to -e delete /mydir | \
while read FILECHANGE
do
    if [ -f $FILECHANGE ]
    then
        rsync --bwlimit=4096 --progress --relative -vrae 'ssh -p 22' $FILECHANGE $REMOTEHOST:/
    else
        ssh -p 22 $REMOTEHOST "rm $FILECHANGE" 0<&-
    fi
done

Now it works.

Script for directory mirroring with inotifywait and ssh

1 Answers1