Monday, May 26, 2008

What is a core.dmp in UNIX?

  • While I'm not familiar with any Unix OS that creates files named core.dmp (Unix systems do not typically use 3 letter suffixes), I can speak to the file commonly called just "core". This file gets created when an application performs an illegal activity, such as referencing an address outside its address space or dividing by zero. Illegal activities result in a synchronous signal being sent to the offending process. Unless handled, the typical result is for an image of the process to be saved to the file called "core". Tools such as "gdb" or "adb" can be used to examine the core file in order to determine what the process was doing that caused it to receive the signal. However, unless the process was compiled with debug information (e.g., -g) and linked with symbols intact, there's precious little that can be deduced. If the process has no symbols nor debug information, the simplest thing to do is to use the "file" command: file core in order to view an abbreviated description (name of the process and the signal that terminated the process).
  • CORE DUMP are images of application failure messages during there execution in LINUX/UNIX they give little clue about what happened to that particular application while run. Cause of application failure may be anything e.g. memory violation, not enough memory or anything that makes an application to stop run. For further refrences please refer to the System Administration Handbook on LINUX that comes from different writers but one that I have read is by Nemeith .

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