apcrash command

The apcrash command runs under UNIX to examine D3 core dumps.


apcrash {core.file}


core.file Name of the core file to examine. If not specified, the default /usr/tmp/ap.core is used.
Note: This file can be very large.


A D3 core dump is created either automatically, when a machine abort occurs (such as bus errors, segmentation violations, and so on) or by requesting a monitor debugger d command.

The core file contains a series of segments, each representing part of the D3 memory at the time the dump was done. Segments can contain both monitor and virtual data. The data in the core file cannot be changed.

The data displays in a format similar to the virtual Debugger. The apcrash command has a format similar to a window (number of bytes displayed). After each window, an equal sign displays, prompting the user for the next action. One character code, followed by pressing ENTER, is required:

n Next window.
p Previous window.
x Redisplay data in hexadecimal.
c Redisplay data in characters.
i Redisplay data in decimal.

The apcrash command displays the prompt (crash) and waits for commands on its standard input:

? Displays Help.
!unix.command Executes the UNIX shell command unix.command.
{.}fid[,|.]dsp{;win} Displays the specified virtual address. The core file must contain either a segment for the appropriate FID, or both the Buffer Table segment and the Virtual Buffer segment, which contains the specified frame.
b{.}fid Displays the buffer table entry associated to the specified FID. The buffer table segment must be present.
l{.}fid Displays the link fields of the specified frame. The core file must contain either a segment for the appropriate FID, or both the buffer table segment and a virtual buffer segment, which contains the specified frame.
m{l|g}{.}addr{;win} Displays real memory.
  • Prefix l specifies a local address (mpcb).

  • g specifies a global address (mcb).

Without the prefix, the address specified is an absolute address.

q or CTRL+D Quits.
s{type} Displays the core segments in the current core file. If the type is specified, only the segments of this type are specified (see ap.core file).
v Displays the monitor version.
x Displays the hardware registers, PCB FID, ra, and ral values and the PIB of the process which made the dump. The Register, PCB, is Global, and Local segments must be in the core file.

See also

ap.core file