richard@aiva.UUCP (08/25/87)
Can anyone explain the following behaviour?
A C shell script ("nizz") runs /bin/cat (or other program requiring input).
I suspend nizz, then put it in the background. As expected, I get the
message 'Stopped (tty input)'. Then I bring it into the foreground.
Now the strange bit: I get another 'Stopped (tty input)' and the process
has vanished.
This happens under 4.3 on a Vax 750. It doesn't happen under 4.2, or
SunOS 3.2, or if I copy the 4.2 csh onto the 4.3 machine and use that.
It doesn't happen if I don't put the program in the background before
bringing it into the foreground.
Here's an example, just in case I wasn't clear:
eusip% cat nizz
#!/bin/csh
/bin/cat
eusip% ./nizz
^X
Stopped
eusip% bg
[1] ./nizz &
[1] + Stopped (tty input) ./nizz
eusip% fg
./nizz
Stopped (tty input)
eusip% ps
PID TT STAT TIME COMMAND
14180 p1 S N 0:24 -tcsh (tcsh)
24950 p1 R N 0:00 ps
eusip%
--
Richard Tobin, JANET: R.Tobin@uk.ac.ed
AI Applications Institute, ARPA: R.Tobin%uk.ac.ed@cs.ucl.ac.uk
Edinburgh University. UUCP: ...!ukc!ed.ac.uk!R.Tobin