3 Replies Latest reply: May 21, 2008 2:14 PM by Karl Zimmerman
Pomona9 Level 1 (0 points)
An icon has suddenly appeared on my dock called pipedaemon - it is a piece of paper with ruler brush and pencil. What is it - I have tried putting in the trash but it won't allow me to empty the trash? I am a bit worried that it is a virus. Can anyone help please?

Imac G5, Mac OS X (10.3.x)
  • Clea Rees Level 4 (1,245 points)
    Take a look at this thread.

    Do you have HP software installed?

    I am not entirely sure about the explanation in that thread. I do have HP software installed but I don't seem to have pipedaemon. It is possible, however, that it is something HP uses on certain machines or with some software but not others?

    - cfr

    Update: see HP's site for possible information. It seems to have something to do with HP printing in Classic on 10.2/10.3.
  • Kappy Level 10 (266,026 points)
    Pipedaemon is a Unix daemon that provides the piping capability of Unix. Pipes are a Unix mechanism for passing the output of one command to the input of another. On a command line it would typically look something like: cat textfile | less. This line would use the "cat" command to list the contents of a textfile. The output is piped to "less" which is another command the formats the output into screen-sized pages.

    There have been discussions for several years regarding HP's possible use of the daemon in its printer drivers for some of its printer models.

    I do not know why it appears in the Dock (it shouldn't) but it's harmless in itself. The icon you see is a generic application icon. You cannot trash it because it's a running process. If you open Activity Monitor you may see it listed. You can then select it and force quit it. However, if it is needed by your printer driver then you may find the printer no longer functions or the daemon will simply be relaunched automatically.

    As far as I know the phenomenon isn't present running Tiger or Leopard. It also may be "fixed" by installing a later version of your HP printer software assuming you are in fact using an HP printer.
  • Karl Zimmerman Level 4 (2,065 points)
    On which *nix does pipedaemon provide basic piping?
    Certainly not on SVr4, nor on Linux.
    For all UNIX variants with which I'm familiar, piping (directing output from one process to become input to another) is implemented directly in the kernel.

    OTOH, when I type 'man pipe' in Terminal, I get a pipe(8) man page that talks about a "pipe daemon" that "processes requests from the Postfix queue manager". Postfix is an email system.

    I suspect that THIS is what pipedaemon is.

    Message was edited by: Karl Zimmerman