Hi all, hopefully someone can help me out with this...
I am looking into using a FIFO / named pipe on FreeBSD for getting some sensitive output out of a program that takes a file output argument. So far I've been having no luck, and I ran some simple testing in a shell and observed what seemed to be really odd behaviour:
In Shell 1:
In Shell 2:
No output comes through in Shell 1. However, if I cat again....
In Shell 2:
...two
Additionally, if I start a fresh
In Shell 1:
In Shell 2:
...only the last 10 lines (of 14,636!) of the sysctl come out through tail.
Am I missing something here or is something busted?
The tests were all run on FreeBSD 13.2-RELEASE-p8 with a ZFS filesystem.
I am looking into using a FIFO / named pipe on FreeBSD for getting some sensitive output out of a program that takes a file output argument. So far I've been having no luck, and I ran some simple testing in a shell and observed what seemed to be really odd behaviour:
In Shell 1:
Code:
mkfifo testfifo
tail -f testfifo
Code:
cat 'a' > testfifo
No output comes through in Shell 1. However, if I cat again....
In Shell 2:
Code:
`cat 'a' > testfifo
...two
a
lines come out through the tail
in Shell 1 - i.e. the shell ends up looking like this:
Code:
[root@machine /home/swebb]# tail -f testfifo
a
a
Additionally, if I start a fresh
tail -f
and instead try piping in sysctl -a
:In Shell 1:
Code:
tail -f testfifo
Code:
sysctl -a > testfifo
...only the last 10 lines (of 14,636!) of the sysctl come out through tail.
Am I missing something here or is something busted?
The tests were all run on FreeBSD 13.2-RELEASE-p8 with a ZFS filesystem.