core(4)                                                             core(4)




 NAME    [Toc]    [Back]
      core - format of core image file

 DESCRIPTION    [Toc]    [Back]
      The HP-UX system writes out a file containing a core image of a
      terminated process when certain signals are received (see signal(5)
      for the list of reasons).  The most common causes are memory
      violations, illegal instructions, floating point exceptions, bus
      errors, and user-generated quit signals.  The core image file is
      called core and is written in the process's working directory
      (provided it is allowed by normal access controls).  A process with an
      effective user ID different from its real user ID does not produce a
      core image.

      The file contains sufficient information to determine what the process
      was doing at the time of its termination.  Core file contents consist
      of objects that represent different segments of a process.  Each
      object is preceded by a corehead data structure, and each corehead
      data structure describes the corresponding object following it.  The
      structure is defined in <sys/core.h>, and includes the following
      members:

           int       type;
           space_t   space;
           caddr_t   addr;
           size_t    len;

      The space and addr members specify the virtual memory address in the
      process where the described object began.  The len member is the
      length of the object in bytes.

      The following possible values for type are defined in <sys/core.h>:

           CORE_DATA         Process data as it existed at the time the core
                             image was created.  This includes initialized
                             data, uninitalized data, and the heap at the
                             time the core image is generated.

           CORE_EXEC         A compiler-dependent data structure containing
                             the exec data structure, the magic number of
                             the executable file, and the command (see the
                             declaration of the proc_exec structure in
                             <sys/core.h>).

           CORE_FORMAT       The version number of the core format produced.
                             This number changes with each HP-UX release
                             where the core format itself has changed.
                             However, it does not necessarily change with
                             every HP-UX release.  CORE_FORMAT can thus be
                             easily used by core-reading tools to determine
                             whether they are compatible with a given core



 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003






 core(4)                                                             core(4)




                             image.  This type is expressed by a four-byte
                             binary integer.

           CORE_KERNEL       The null-terminated version string associated
                             with the kernel at the time the core image was
                             generated.

           CORE_PROC         An architecture-dependent data structure
                             containing per-process information such as
                             hardware register contents.  See the
                             declaration of the proc_info structure in
                             <sys/core.h>.

           CORE_STACK        Process stack contents at the time the core
                             image was created.

      Objects dumped in a core image file are not arranged in any particular
      order.  Use corehead information to determine the type of the object
      that immediately follows it.

 SEE ALSO    [Toc]    [Back]
      adb(1), cdb(1), xdb(1), setuid(2), crt0(3), end(3C), signal(5).


 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003