On Tuesday 14 November 2006 19:00, Darryl Gregorash wrote: > On 2006-11-14 17:20, Theo v. Werkhoven wrote: > > Tue, 14 Nov 2006, by [EMAIL PROTECTED]: > > > > > > <snip> > > > >> The end result must be a file, and I do not know if a named pipe > >> qualifies as a file in mozilla's language. If it does, then I can > >> just insert "sig" as the signature file, but I am not prepared to > >> go through the exercise. I will leave that to Hylton, if he is > >> interested. > > > > So will I. > > Well, I tried it anyway.. trying to read a named pipe in Seamonkey > just hangs.
Pipe semantics are perhaps a bit odd. Readers block if there's at least one writer present (i.e., a process that has the pipe open for writing). If there are no writers, readers get and EOF (reads immediately return a count of 0 bytes read). If a writer writes when there are no readers present, the write is discarded and the writing process is sent a SIGPIPE. Writers will block once they reach the high-water mark for pipes, which is something in the 8-16 K mark (I'm guessing--it may be higher these days). If there are multiple writers, there are no guarantees about relative ordering of concurrent writes. Likewise for multiple readers, but no byte written will be read by more than one reader. If you want to use pipes, you need to keep these things in mind. Named pipes are no different than conventional ones, except that the reader and writers need have no common process parentage from which to have inherited the open pipe descriptors. Randall Schulz --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
