redirection in ksh

[vlz]

Hi,
Could you help me to find out what is wrong in my script?

#!/bin/ksh
exec 3 >> log
{
print start
print -u2 error
print -u3 "only to logfile"
print end
} 2>&1 |tee log

I get on my terminal and in the log file the same:
start
error
end

But I expect to get in the log file:
start
error
only to logfile
end

Thanks in advance,
Vadim

 

[ericbrunson]

I think the problem is that your exec opens the file, then the tee, in another process, opens the file with another file handle. If the >> redirection writes to log, it doesn't make the file pointer for tee advance and a subsequent write by tee overwrites the output. Note that even if there is no write from tee after &3 output, tee will still write the EOF marker where it stops.

 

[vlz]

Is it possible to get log file as I expect?

Thanks,
Vadim

 

[ericbrunson]

Not using an external program like "tee". Did you try redirecting &1 and &2 to the log file?

 

[ericbrunson]

Well, then you wouldn't get your output to the screen... I don't know, maybe you're being too picky. You may have to duplicate your output lines to write once to log and once to std out.