1CORE(5)                       File Formats Manual                      CORE(5)
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NAME

6       core - format of memory image file
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SYNOPSIS

9       #include <sys/param.h>
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DESCRIPTION

12       The  UNIX System writes out a memory image of a terminated process when
13       any of various errors occur.  See sigvec(2) for the  list  of  reasons;
14       the  most  common  are  memory  violations,  illegal  instructions, bus
15       errors, and user-generated quit signals.  The memory  image  is  called
16       `core'  and  is written in the process's working directory (provided it
17       can be; normal access controls apply).
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19       The core file consists  of  the  u.   area,  whose  size  (in  64  byte
20       `clicks')  is  defined by the USIZE manifest in the <sys/param.h> file.
21       The u.  area starts with a user structure  as  given  in  <sys/user.h>.
22       The  rest  of  the u.  area consists of the kernel stack for the termi‐
23       nated process which includes (among other things) the processor  regis‐
24       ters  at  the time of the fault; see the system listings for the format
25       of this area.  The remainder of the core file  consists  first  of  the
26       data  pages  and then the stack pages of the process image.  The amount
27       of data space image in the core file is given (in clicks) by the  vari‐
28       able  u_dsize  in the u.  area.  If the text segment was not write-only
29       and and shared it is included as the first  etext  bytes  of  the  data
30       image  where  etext  is  taken from the symbol table of the object file
31       which generated the memory image.  The amount of  stack  image  in  the
32       core file is given (in clicks) by the variable u_ssize in the u.  area.
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34       In general the debugger adb(1) is sufficient to deal with core images.
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SEE ALSO

37       adb(1), sigvec(2), stack(5)
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413rd Berkeley Distribution      January 26, 1987                        CORE(5)
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