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Karthik C
Asked: 2013-07-03 03:23:00 +0800 CST

Detect error of a running process?

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I have a to execute a process that sometimes produces an error. However every time it produces that error, it doesn't exit the process.

aneesh@nb-14:~$ emulator -no-boot-anim -avd Andreud
Emulator ERROR: Unable to load VM from snapshot. The snapshot file was saved for a
different hardware configuration
^Z
aneesh@nb-14:~$ emulator -no-boot-anim -avd Andreud

On success the cursor is at the beginning of the second line above and the emulator error doesn't show up. On failure it shows the error but I am forced to stop it. The commands might seem to show that this question is off-topic.

However my question is how (via a command) to detect this error while this process is still running and if yes kill it.

12.04

1 Answers

  1. Best Answer

    Launch the emulator in the background, sending all of its output to a temporary file

    emulator -no-boot-anim -avd Andreud &>/tmp/emulator-output &

    Then get the PID of the recently launched process, and store it in a variable called EMULATORPID

    EMULATORPID=$!

    Then, while the emulator is still running, watch the output file for the error, and when it is found, kill the process by PID:

    while ps -p$EMULATORPID ; do
   grep "Emulator ERROR" /tmp/emulator-output && kill $EMULATORPID
done

    To satisfy the additional requirement of quitting the while loop after five seconds, you could set a counter, increment it each loop, and add a delay of one section to each iteration like so:

      CTR=0
  while ps -p$EMULATORPID &&  [ $CTR -lt 5 ]  ; do
     grep "Emulator ERROR" /tmp/emulator-output && kill $EMULATORPID
     sleep 1s;
     CTR=$[CTR+1] 
  done
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