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UNW_GET_REG(3)		     Programming Library		UNW_GET_REG(3)

NAME
       unw_get_reg -- get register contents

SYNOPSIS
       #include	<libunwind.h>

       int unw_get_reg(unw_cursor_t *cp, unw_regnum_t reg, unw_word_t *valp);

DESCRIPTION
       The  unw_get_reg() routine reads	the value of register reg in the stack
       frame identified	by cursor cp and stores	the value in the word  pointed
       to by valp.

       The  register  numbering	 is target-dependent and described in separate
       manual pages (e.g., libunwind-ia64(3) for the IA-64 target).   Further-
       more,  the  exact set of	accessible registers may depend	on the type of
       frame that cp is	referring to. For ordinary stack frames,  it  is  nor-
       mally  possible	to access only the preserved (``callee-saved'')	regis-
       ters and	frame-related registers	(such as the stack-pointer).  However,
       for  signal frames (see unw_is_signal_frame(3)),	it is usually possible
       to access all registers.

       Note that unw_get_reg() can only	read the contents of  registers	 whose
       values  fit  in	a  single word.	See unw_get_fpreg(3) for a way to read
       registers which do not fit this constraint.

RETURN VALUE
       On successful completion, unw_get_reg() returns 0.  Otherwise the nega-
       tive value of one of the	error-codes below is returned.

THREAD AND SIGNAL SAFETY
       unw_get_reg()  is thread-safe as	well as	safe to	use from a signal han-
       dler.

ERRORS
       UNW_EUNSPEC
	       An unspecified error occurred.

       UNW_EBADREG
	       An attempt was made to read a register that is  either  invalid
	      or not accessible	in the current frame.

       In  addition,  unw_get_reg()  may  return any error returned by the ac-
       cess_mem(), access_reg(), and access_fpreg() call-backs	(see  unw_cre-
       ate_addr_space(3)).

SEE ALSO
       libunwind(3),	libunwind-ia64(3),    unw_get_fpreg(3),	   unw_is_sig-
       nal_frame(3), unw_set_reg(3)

AUTHOR
       David Mosberger-Tang
       Email: dmosberger@gmail.com
       WWW: http://www.nongnu.org/libunwind/.

Programming Library		16 August 2007			UNW_GET_REG(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | THREAD AND SIGNAL SAFETY | ERRORS | SEE ALSO | AUTHOR

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