Run exec on cron script carefully

Question

i would like to change permissions of a file after rsync backups a file in my cron script, i was going to append an exec command to this command line, but i would like to know how to do it carefully so im not blowing up any other files.
rsync -a --delete /home/backup/sqldumps /mnt/smb/backup/ &> /dev/null
i was considering something like
rsync -a --delete /home/backup/sqldumps /mnt/smb/backup/ &> /dev/null && -exec chmod 550 {} \;
but i was fearing that it might exec on the entire root, and or not run at the right time on the right file.
im having a hard time finding documentation on the latter portion of the exec command to know what the {} and \; does again.  i forget.....  im assuming that part may not be needed and causes recursion. 
im going about it a bit lazy as well, and to keep the overhead lower, otherwise i would just run the rsync command first, then on the 2nd line do a find exec for a matching file for some criteria.
can anyone shed some light on this?
Last edited by wolfdogg (2014-01-06 18:41:41)

Answer 1

wolfdogg wrote:im having a hard time finding documentation on the latter portion of the exec command to know what the {} and \; does again.
There is no `-exec` command.  There is an -exec option to the `find` command, but you are not running find.  Unless the current man page is out of date, rsync has no -exec option like that.
Further, if you put it after the && you would not be passing an -exec option to rsync.  Instead you'd be trying to run /usr/bin/-exec, or an -exec somewhere else in your path.
The '{}' and \; are documented in the find man page as (again) they are specific to the syntax for find's -exec flag.  They are not a separate command or shell option.