Very Computer

by **Manja Fieber** » Sat, 13 Nov 1999 04:00:00

Hi,

I'd like to decompress 3 files, concatenate them and pipe the output in
another process without storing intermediate files. The 3 compressed
files are about 10 GB, the decompressed ones 30-40 GB. Does something
like

mknod /dev/hugo p
uncompress file1.Z > /dev/hugo
uncompress file2.Z > /dev/hugo
uncompress file3.Z > /dev/hugo

work when I start a reading process like
cp /dev/hugo file &
in background?

The question is, if the pipe is open the whole time and what happens, if
the read from the pipe is very slow.
Does anyone have a suggestion?
Thanks,
Manja Fieberg

by **Martin Shiel** » Sat, 13 Nov 1999 04:00:00

> Does something
> like

> mknod /dev/hugo p
> uncompress file1.Z > /dev/hugo
> uncompress file2.Z > /dev/hugo
> uncompress file3.Z > /dev/hugo

> work when I start a reading process like
> cp /dev/hugo file &
> in background?

> The question is, if the pipe is open the whole time and what happens, if
> the read from the pipe is very slow.

Since each of "uncompress file1.Z > /dev/hugo" ends with EOF, the
background cp process will finish before the second uncompress.

Why not just do:

zcat file1.Z file2.Z file3.Z > file

???

Martin Shields.

Very Computer

writing to pipe

writing to pipe

writing to pipe