cr_read.3 (2010 09)

c
cr_read(3) cr_read(3)
NAME
cr_read - read from crash dump
SYNOPSIS
#include <libcrash.h>
int cr_read(CRASH *crash_cb, void *buf,
uint64_t mem_page, int *num_pages);
DESCRIPTION
The cr_read() function attempts to read the memory area defined by mem_page and num_pages into
the buffer pointed to by buf from the crash dump opened using crash_cb .
The
cr_read() starts at the position in the crash dump associated with the physical memory offset
given by mem_page. If the physical memory page mem_page does not exist in the crash dump,
cr_read() sets *num_pages to 0 and returns 0.
No data transfer will occur past a page of memory that does not exist in the crash dump. If the starting
position, mem_page , plus the read length, *num_pages , goes past an area of memory that does not exist
in the crash dump,
cr_read() sets *num_pages to the number of consecutive pages (starting at
mem_page) actually read.
RETURN VALUE
Returns zero for success. Other possible return values are described in libcrash (5).
EXAMPLES
Assuming a process opened a crash dump, the following call to cr_read (3) reads the first
CRSIZE pages
from the crash dump into the buffer pointed to by mybuf:
#include <libcrash.h>
CRASH in_cb;
char mybuf[CRSIZE*NBPG];
int rstat;
int size = CRSIZE;
rstat = cr_read (in_cb, mybuf, 0, &size);
WARNINGS
cr_read() may return fewer pages than requested due to implementation details. Always check the
number of pages returned. If they are fewer than requested, issue a new request starting at the first page
not returned. Only if that new request reads zero pages (or returns an error) can you be sure that the
page was not dumped.
AUTHOR
cr_read() was developed by HP.
SEE ALSO
cr_open(3), libcrash(5).
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1