vkr@osupyr.mast.ohio-state.edu (Vidhyanath K. Rao) (11/16/88)
I tried using the pipe device in the 1.3 package together with the tee program from comp.sources.amiga. The `feature' also occurs with tee.rexx. I have tried the following: Open two CLI's (or shells). In one do any of the following: <some program> >Pipe:a (I started with maple, but that shouldn't matter) copy * to pipe:a tee pipe:a In the other window, do tee <pipe:a ram:x There is a lag between what is supposed to go into the pipe: and when it comes out. The later two options above indicate that the output from the pipe comes in 256 byte blocks till end-of-file is reached. But the manual says that pipe is transparant. C manuals say that `fopen' is unbuffered. [Maple kernal is, I believe, written in Manx C]. I am lost as to what is going on. Is there any way to have a tee that spills everything it has recieved so far. I really need this to use Maple meaningfully. Incidentally, in case this is pipe:'s fault, do other pipes behave in a similar fashion? I was trying to put off buying WShell, but if it will tee properly ... Also the tee from comp.sources.amiga doesn't seems to handle EOF correctly. The tee getting its input from the pipe doesn't know that it has got an EOF if the feeder to the pipe is "tee pipe:<name>". Thanks in advance for your help.
brant@uf.msc.umn.edu (Gary Brant) (11/17/88)
In article <1056@osupyr.mast.ohio-state.edu> vkr@osupyr.mast.ohio-state.edu (Vidhyanath K. Rao) writes: >I tried using the pipe device in the 1.3 package together with the tee >program from comp.sources.amiga. The `feature' also occurs with tee.rexx. > >I have tried the following: Open two CLI's (or shells). In one do any of >the following: > <some program> >Pipe:a (I started with maple, but that shouldn't matter) > copy * to pipe:a > tee pipe:a >In the other window, do > tee <pipe:a ram:x >There is a lag between what is supposed to go into the pipe: and when it >comes out. The later two options above indicate that the output from the >pipe comes in 256 byte blocks till end-of-file is reached. But the manual >says that pipe is transparant. C manuals say that `fopen' is unbuffered. The choppiness you notice is due to the 256 byte buffer size in tee; it is much more apparent if you have more than one tee running in the same pipeline. This effect does not appear with the Dillon/Drew shell's piping mechanism ( prog1 | prog2 ) because temporary ram: files are used for the pipe. >[Maple kernal is, I believe, written in Manx C]. I am lost as to what is >going on. Is there any way to have a tee that spills everything it has >recieved so far. I really need this to use Maple meaningfully. > >Incidentally, in case this is pipe:'s fault, do other pipes behave in a >similar fashion? I was trying to put off buying WShell, but if it will >tee properly ... > >Also the tee from comp.sources.amiga doesn't seems to handle EOF correctly. >The tee getting its input from the pipe doesn't know that it has got an >EOF if the feeder to the pipe is "tee pipe:<name>". I know, I know; when I submitted this, 1.3 enhancer kits hadn't made it to Minnesota yet, and so I had not been able to test this with a real pipe ;-) Manx read apparently returns a zero when the pipe: is empty, this is also the end-of-file signal. A new version is nearly ready which works with pipe:. If you need something immediately, send me mail & I will send you source/uuencoded binary. > >Thanks in advance for your help. You're welcome. I don't have a .signature... -Gary Brant ARPA: brant@uf.msc.umn.edu