Shell Programming and Scripting

Hi,
i have a problem with turning a job into backgrund.
When i enter this at the shell:

spice -b darlington.cir -r output.raw > screenout.tmp &

and then let me show the currently running jobs, i get the following output:

[2] + Suspended (tty output) spice -b darlington.cir -r output.raw > screenout.tmp

Why is the job suspended??
Does somebody know how to solve this problem?

Thank you very much!
greetings

Please don't post duplicate threads in multiple forums. If somebody can offer you their assistance, they will - posting more than once will not yield a faster response! I have removed the duplicate post.

Please review the forum rules, in particular, rule 4.

EDIT: In response to the actual question, it is possible that the script/program is actually wanting input. On some OS's you can do "read foo &" and it will appear as suspended (tty output). I've seen this behaviour on Solaris (tcsh) before. e.g

Code:

% read foo &
[1] 7169
%	
[1]  + Stopped (tty output) read foo

Try running the command interactively without the "&" - does it prompt for any input?

Cheers
ZB

I always believe error messages until they are proven wrong. I have to believe that job is suspended because it wants to write on the controlling terminal.

To be more specific, there are two signals used for background processes:
SIGTTIN background process attempting read
SIGTTOU background process attempting write

Both of these deal with reads and writes to the controlling terminal. In the case of a read, there is no option, the signal gets delivered to the process. In the call of a write, this is user configurable. "stty -tostop" will disable the generation of SIGTOU thus allowing a background process to write.

And ZB, are you sure it wasn't "suspended (tty input)"? Both messages can appear and I don't recall a shell mistaking one state for the other. But I don't use tcsh either.

This was a Solaris 8 for i386 box... I usually use ksh, but I saw this problem on another site, and replicated it on my old sun box. I've since upgraded it to Solaris 9 - I'll check it out when I get home. On Linux, the same command yields the expected result of "stopped (tty input)" as you'd expect.

I know that zsh had a few bugs regarding this too - but I'm not sure if the OP uses the Z shell.

Which shell and OS are you using, qsi?

EDIT: Just tried under Solaris 9 - using ksh:

Code:

$ read foo &
[1] 360
$
[1] + Stopped (SIGTTOU) read foo &

Cheers
ZB

Hi,
without the "&" the program runs; it doesn't promt for input. I also tried Perderabo's hint, but the program also got suspended...

My OS is Solaris 8. I use the tcsh. But it seems to be the same problem in Bourne-Shell. I built the command-line into a shell-script, which i run under sh, the script also got suspended (also because of spice).

greetings