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 \documentclass{article} \usepackage[fancyhdr,pdf]{latex2man} \input{common.tex} \begin{document} \begin{Name}{3}{unw\_get\_reg}{David Mosberger-Tang}{Programming Library}{unw\_get\_reg}unw\_get\_reg -- get register contents \end{Name} \section{Synopsis} \File{\#include $<$libunwind.h$>$}\\ \Type{int} \Func{unw\_get\_reg}(\Type{unw\_cursor\_t~*}\Var{cp}, \Type{unw\_regnum\_t} \Var{reg}, \Type{unw\_word\_t~*}\Var{valp});\\ \section{Description} The \Func{unw\_get\_reg}() routine reads the value of register \Var{reg} in the stack frame identified by cursor \Var{cp} and stores the value in the word pointed to by \Var{valp}. The register numbering is target-dependent and described in separate manual pages (e.g., libunwind-ia64(3) for the IA-64 target). Furthermore, the exact set of accessible registers may depend on the type of frame that \Var{cp} is referring to. For ordinary stack frames, it is normally possible to access only the preserved (callee-saved'') registers and frame-related registers (such as the stack-pointer). However, for signal frames (see \Func{unw\_is\_signal\_frame}(3)), it is usually possible to access all registers. Note that \Func{unw\_get\_reg}() can only read the contents of registers whose values fit in a single word. See \Func{unw\_get\_fpreg}(3) for a way to read registers which do not fit this constraint. \section{Return Value} On successful completion, \Func{unw\_get\_reg}() returns 0. Otherwise the negative value of one of the error-codes below is returned. \section{Thread and Signal Safety} \Func{unw\_get\_reg}() is thread-safe as well as safe to use from a signal handler. \section{Errors} \begin{Description} \item[\Const{UNW\_EUNSPEC}] An unspecified error occurred. \item[\Const{UNW\_EBADREG}] An attempt was made to read a register that is either invalid or not accessible in the current frame. \end{Description} In addition, \Func{unw\_get\_reg}() may return any error returned by the \Func{access\_mem}(), \Func{access\_reg}(), and \Func{access\_fpreg}() call-backs (see \Func{unw\_create\_addr\_space}(3)). \section{See Also} \SeeAlso{libunwind(3)}, \SeeAlso{libunwind-ia64(3)}, \SeeAlso{unw\_get\_fpreg(3)}, \SeeAlso{unw\_is\_signal\_frame(3)}, \SeeAlso{unw\_set\_reg(3)} \section{Author} \noindent David Mosberger-Tang\\ Email: \Email{dmosberger@gmail.com}\\ WWW: \URL{http://www.nongnu.org/libunwind/}. \LatexManEnd \end{document}