GELF_GETNOTE(3)		   Libelf Programmer's Manual		 GELF_GETNOTE(3)

NAME
     gelf_getnote  - Get class-independent note information at the supplied off-
     set


SYNOPSIS
     #include <gelf.h>

     size_t gelf_getnote (Elf_Data *data, size_t offset, GElf_Nhdr *result, size_t *name_offset, size_t *desc_offset);


DESCRIPTION
     Retrieve the ELF note header from data at offset offset and store it  in  a
     class-independent	representation	pointed to by result.  The note name and
     note descriptor offsets relative  to  the	start  of  data	 are  stored  in
     *name_offset  and	*desc_offset,  respectively.  GElf_Nhdr fields n_namesz,
     n_descsz, and n_type describe the note's name length, descriptor length and
     type, respectively.  Alignment and padding of the note data entry are  han-
     dled  automatically  by this function.  See elf(5) for more information re-
     garding ELF notes.


PARAMETERS
     data   Pointer to an Elf_Data associated  with  a	SHT_NOTE  section  or  a
	    PT_NOTE segment.  data->d_type should be ELF_T_NHDR or ELF_T_NHDR8.


     offset
	    Offset of a note header within data.


     result
	    Pointer to a caller-provided GElf_Nhdr structure for storing the re-
	    quested note header.  result must not be NULL.


     name_offset
	    Pointer  to	 a caller-provided size_t for storing the name offset of
	    the	 requested  note.   This  offset  is  relative	to  data->d_buf.
	    name_offset must not be NULL.


     desc_offset
	    Pointer  to a caller-provided size_t for storing the descriptor off-
	    set of the requested note. This offset is relative	to  data->d_buf.
	    desc_offset must not be NULL.


RETURN VALUE
     On	 success,  this function updates *result, *name_offset, and *desc_offset
     and returns the offset of the next note.  If there are no	notes  remaining
     then  the return value will be greater than or equal to the d_size of data.
     On failure, this function returns zero and sets elf_errno.	 If data is NULL
     then zero is returned without setting elf_errno.


EXAMPLE
       size_t offset = 0;
       GElf_Nhdr nhdr;
       size_t name_offset;
       size_t desc_offset;
       while (offset < data->d_size
	      && (offset = gelf_getnote (data, offset,
					 &nhdr, &name_offset, &desc_offset)) > 0)
	 {
	   const char *name = nhdr.n_namesz == 0 ? "" : data->d_buf + name_offset;
	   const char *desc = nhdr.n_descsz == 0 ? "" : data->d_buf + desc_offset;

	   /* Process note here.  name and desc are not guaranteed to be
	      zero-terminated.	The presence of null characters should be
	      verified using n_namesz and n_descsz.  */
	   [...]
	 }


SEE ALSO
     libelf(3), elf(5)


ATTRIBUTES
     allbox; lbx lb lb l l l.  Interface Attribute Value T{ gelf_getnote()
     T}	  Thread safety	  MT-Safe


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


HISTORY
     gelf_getnote  first  appeared in elfutils 0.130.  This function is an elfu-
     tils libelf extension and may not be available in other libelf  implementa-
     tions.

Libelf				   2025-12-31			 GELF_GETNOTE(3)