ELFGETIDENT(3E) ELFGETIDENT(3E)
NAME
elfgetident - retrieve file identification data
SYNOPSIS
cc [flag ...] file ... -lelf [library ...]
#include <libelf.h>
char *elfgetident(Elf *elf, sizet *ptr);
DESCRIPTION
As elf(3E) explains, ELF provides a framework for various classes of
files, where basic objects may have 32 bits, 64 bits, etc. To
accommodate these differences, without forcing the larger sizes on
smaller machines, the initial bytes in an ELF file hold identification
information common to all file classes. Every ELF header's eident has
EINIDENT bytes with the following interpretation.
eident Index Value Purpose
__________________________________________________
| |
EIMAG0 ELFMAG0
| |
EIMAG1 ELFMAG1
| |
EIMAG2 ELFMAG2 File identification
| |
EIMAG3 ELFMAG3
| |
______________|______________|____________________
| ELFCLASSNONE |
EICLASS | ELFCLASS32 | File class
| ELFCLASS64 |
______________|______________|____________________
| ELFDATANONE |
EIDATA | ELFDATA2LSB | Data encoding
| ELFDATA2MSB |
______________|______________|____________________
EIVERSION | EVCURRENT | File version
| |
__________________________________________________
| |
7-15 0 Unused, set to zero
| |
______________|______________|____________________
Other kinds of files [see elfkind(3E)] also may have identification
data, though they would not conform to eident.
elfgetident returns a pointer to the file's ``initial bytes.'' If the
library recognizes the file, a conversion from the file image to the
memory image may occur. In any case, the identification bytes are
guaranteed not to have been modified, though the size of the unmodified
area depends on the file type. If ptr is non-null, the library stores
the number of identification bytes in the location to which ptr points.
If no data are present, elf is null, or an error occurs, the return value
is a null pointer, with zero optionally stored through ptr.
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ELFGETIDENT(3E) ELFGETIDENT(3E)
SEE ALSO
elf(3E), elfbegin(3E), elfgetehdr(3E), elfkind(3E), elfrawfile(3E).
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