file descriptors, redirection and other animals....

[simonm]

Hi all,

Here's a quick one...

The following works as expected:

# exec 9<>test.file ; jot 50 >&9 ; tail  -5 <&9 9>&-
46
47
48
49
50

The next one does not:

# exec 9<>test.file ; jot 50 >&9 ; head  -5 <&9 9>&-
#

The question is: Why?

bash --version
GNU bash, version 3.2.17(1)-release (i386-apple-darwin9.0)
Copyright (C) 2005 Free Software Foundation, Inc.

I'd like to "split" output from a pipe to perform multiple end-steps
after a long-chain of pipes. FD redirection seems to be the best way.

Many thanks in advance for any ideas as to why "head" doesn't work and
"tail" does.

Thanks

SM