Problem
Assuming that you need to save both standard and error logs by two processes on a same file.
$ command1
mesg...
error...
mesg...
....
$ command2
mesg...
mesg...
mesg...
error..
....
How to do that? The following code looks good, but it doesn't work as you want.
$ (command1 >& log.txt) &
$ (command2 >& log.txt) &
You can find only the logs of command2.
How about trying this?
$ (command1 2>&1 >> log.txt) &
$ (command2 2>&1 >> log.txt) &
It is better, but it doesn't work as you want as well. The result is not chronically ordered because of buffering.
Solution
Do the following code:
$ (command1 2>&1 | cat >> log.txt) &
$ (command2 2>&1 | cat >> log.txt) &
It's tricky. The part of | cat >> means not to buffer the outputs.
Interesting. But when I try to capture STDOUT and STDERR I define the output to STDOUT first, then point STDERR to that same stream. I.E.:
ReplyDelete( command1 >>log.txt 2>&1 ) &
( command2 >>log.txt 2>&1 ) &
this seems to work for me. Does it for you?
Cheers
Eric
Interesting. thanks!
ReplyDelete