Is it better to have one daemon or many daemons? I know the answer is supposed to be one daemon. That's why we have inetd. However, I am running a bunch of small bash scripts as daemons to watch directories to enable xv's visual schnauzer to be used as a slide sorter. Here is my process table: 23817 pts/1 S 0:00 /bin/bash ./exchange.scr 23818 pts/1 S 0:00 /bin/bash ./delete.scr 23822 pts/1 S 0:00 /bin/bash ./label.scr 23823 pts/1 S 0:00 /bin/bash ./move.scr 23824 pts/1 S 0:00 /bin/bash ./restore.scr 23831 pts/1 S 0:00 /bin/bash ./renumber.scr 23832 pts/1 S 0:00 /bin/bash ./duplicate.scr 23833 pts/1 S 0:00 /bin/bash ./startxv.scr 2616 pts/1 S 0:02 xv -vsmap -vsgeometry 1000x680 -geometry 75x50 4028 pts/1 S 0:00 sleep 1 4030 pts/1 S 0:00 sleep 1 4032 pts/1 S 0:00 sleep 1 4037 pts/1 S 0:00 sleep 1 4039 pts/1 S 0:00 sleep 1 4041 pts/1 S 0:00 sleep 1 4043 pts/1 S 0:00 sleep 1
Each daemon looks at a particular directory. If it is empty, it sleeps for a second. If it is not empty, it does stuff, eg., renames files, labels them with convert, mv's them to other directories, and so on. When it is done, each daemon kills xv, and the startxv.scr script restarts xv. This latter nuisance is because the visual schnauzer has to be updated by hand if you don't restart xv. Essentially, each daemon is an independent contractor. That is to say, they all operate independently. That made programming this fairly simple. Things seems to be working. However, before I turn this loose at work, is this approach feasible? For example, would I be better off making one big daemon? In theory, an impatient user might move faster than the daemons (old, slow bash scripts), and a collision might occur. For example, if they tried to delete slides while the fairly slow labeling daemon was running, this might cause some interesting effects. Would it be feasible to cascade the daemons? That is to say, could the daemons call each other sequentially, thereby at least avoiding collisions? Or, would a master script which calls each daemon sequentially be preferable? Any comments appreciated, Joel _______________________________________________ Linux-users mailing list [EMAIL PROTECTED] Unsubscribe/Suspend/Etc -> http://www.linux-sxs.org/mailman/listinfo/linux-users
