[aidos]

Useful. I'm assuming those are cases where normal pipes would fail too? So you can't do:

    cat z | unzip   # I know, uuoc, demo only

It's just with the process substitution you have more flexibility to shoot yourself in the foot?

[Wicher]

Aside: If I recall correctly, with the zip file format, the index is at the end of the file. A (named) pipe works fine with, for instance, a bzipped tarball.

I wouldn't be surprised if the ZIP file format has its origins outside the Unix world given its pipe-unfriendlyness.

[david-given]

stdin and stderr are assumed to always be streams, so anything which accepts them won't seek on them.

However, if you give a program a filename on a command line, the program's likely to assume it's an actual file.