.TH GELF_GETAUXV 3 2025-12-31 "Libelf" "Libelf Programmer's Manual"

.SH NAME
gelf_getauxv \- Get class\-independent information from auxiliary vector at the given index

.SH SYNOPSIS
.nf
.B #include <gelf.h>

.BI "GElf_auxv_t *gelf_getauxv (Elf_Data *" data ", int " ndx ", GElf_auxv_t *" dst ");"

.SH DESCRIPTION
Retrieve an auxiliary vector entry from
.I data
at index
.I ndx
and store it in the class\-independent representation pointed to by
.IR dst .

.PP
.I data
must be an
.B Elf_Data*
associated with an ELF note of type
.BR NT_AUXV
and must have its
.B d_type
set to
.BR ELF_T_AUXV .
.BR elf_getdata_rawchunk (3)
can be used to acquire an
.B Elf_Data*
with a
.B d_type
of
.BR ELF_T_AUXV .
.B NT_AUXV
notes are normally found in core files.  The auxiliary vector can be also be
read directly from /proc/PID/auxv.

See
.BR getauxval (3)
for more information regarding the auxiliary vector.

.SH PARAMETERS
.TP
.I data
Pointer to an
.B Elf_Data
of a note with type
.B NT_AUXV
and must have its
.B d_type
set to
.BR ELF_T_AUXV .
See
.BR elf_getdata_rawchunk (3)
for more information.

.TP
.I ndx
Index of the requested auxiliary vector entry within
.IR data .

.TP
.I dst
Pointer to a caller\-provided
.B GElf_auxv_t
structure for storing the requested auxiliary vector entry.
Must not be NULL.

.SH RETURN VALUE
On success, this function updates
.I dst
with the requested auxiliary vector entry and returns
.IR dst .
On failure, it returns NULL and sets elf_errno.  If
.I data
is NULL, then NULL is returned without setting elf_errno.

.SH SEE ALSO
.BR elf_getdata_rawchunk (3),
.BR getauxval (3)
.BR libelf (3),
.BR elf (5)

.SH ATTRIBUTES
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR gelf_getauxv ()
T}	Thread safety	MT-Safe
.TE

.SH REPORTING BUGS
Report bugs to <elfutils-devel@sourceware.org> or https://sourceware.org/bugzilla/.

.SH HISTORY
.B gelf_getauxv
first appeared in elfutils 0.130.  This function is an elfutils libelf extension and
may not be available in other libelf implementations.