intercept stdout/stderr of another process

strace -ff -e trace=write -e write=1,2 -p SOME_PID

57
By: oernii2
2010-04-20 08:55:54

2 Alternatives + Submit Alt

  • similar to the previous command, but with more friendly output (tested on linux)


    10
    strace -ff -e write=1,2 -s 1024 -p PID 2>&1 | grep "^ |" | cut -c11-60 | sed -e 's/ //g' | xxd -r -p
    systemj · 2010-04-23 16:22:17 0
  • Useful to recover a output(stdout and stderr) "disown"ed or "nohup"ep process of other instance of ssh. With the others options the stdout / stderr is intercepted, but only the first n chars. This way we can recover ALL text of stdout or stderr Show Sample Output


    3
    strace -e write=1,2 -p $PID 2>&1 | sed -un "/^ |/p" | sed -ue "s/^.\{9\}\(.\{50\}\).\+/\1/g" -e 's/ //g' | xxd -r -p
    glaudiston · 2010-10-06 19:37:39 1

What Others Think

Brilliant. Works like a charm on RHEL 4.
slower · 424 weeks and 4 days ago
In ubuntu 14.04 watch ls Ctr + z sent to suspend bg %1 diswon %1 sudo strace -ff -e trace=write -e write=1,2 -p 19637 Process 19637 attached --- stopped by SIGTTOU --- No output is shown. Any reason?
udaraliyanage · 223 weeks and 2 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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