Messages in this thread | | | Date | Thu, 5 Aug 2004 10:34:11 -0400 (EDT) | From | William Stearns <> | Subject | Re: Program-invoking Symbolic Links? |
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Good morning, John, (My apologies for floating offtopic for kernel programming. I wanted to provide a quick example for John and others interested in doing this so they could see this can be done outside of the kernel.)
On Thu, 5 Aug 2004, John M Collins wrote:
> (Please CC any reply to jmc AT xisl.com as I'm not subbed - thanks). > > I wondered if anyone had ever thought of implementing an alternative form of > symbolic link which was in fact an invocation of a program? > > Such a symbolic link would "do all the necessary" to fork off a new process > running the specified program with input or output from or to a pipe > depending on whether the link was opened for writing or reading respectively. > RW access would probably have to be banned and the link would usually be > read-only or write-only. > > What I originally wanted was symbolic links (with "=>" as a possible > notation). > > latest_version.tar => "tar cf - /latest/and/greatest" > latest_version.tgz => "gzip -c latest_version" > > and the like, which I could link on a website so I didn't have to run around > updating tar files/zip files/gzipped tar files etc each time I fix a bug in > some package.
Is there any reason this couldn't be done in userspace by using named pipes instead of a new form of symlink?
#!/bin/bash
if [ ! -e livepipe ]; then echo Making livepipe >&2 mkfifo livepipe fi
while : ; do echo -n . >&2 ( date ) >livepipe sleep 1 done
Run this, and then from another window, simply do: cat livepipe To see the date, or whatever output is provided by the subshell. I'd like to sincerely request that further discussion _not_ continue on linux-kernel - please respond privately. Cheers, - Bill
--------------------------------------------------------------------------- "Eagles may soar, high and proud, but weasels don't get sucked into jet engines." (Courtesy of Mike Andrews <mandrews@termfrost.org>) -------------------------------------------------------------------------- William Stearns (wstearns@pobox.com). Mason, Buildkernel, freedups, p0f, rsync-backup, ssh-keyinstall, dns-check, more at: http://www.stearns.org -------------------------------------------------------------------------- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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