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elf_getehdr(3elf)


elf_getehdr: elf32_getehdr, elf32_newehdr, elf64_getehdr, elf64_newehdr -- retrieve class-dependent object file header

Synopsis

   cc [flag . . . ] file . . . -lelf [library] . . .
   

#include <libelf.h>

Elf32_Ehdr *elf32_getehdr(Elf *elf);

Elf32_Ehdr *elf32_newehdr(Elf *elf);

Elf64_Ehdr *elf64_getehdr(Elf *elf);

Elf64_Ehdr *elf64_newehdr(Elf *elf);

Description

For a 32-bit class file, elf32_getehdr returns a pointer to an ELF header, if one is available for the ELF descriptor elf. If no header exists for the descriptor, elf32_newehdr allocates a ``clean'' one, but it otherwise behaves the same as elf32_getehdr. It does not allocate a new header if one exists already. If no header exists (for elf_getehdr), one cannot be created (for elf_newehdr), a system error occurs, the file is not a 32-bit class file, or elf is null, both functions return a null pointer.

The header includes the following members.


unsigned char e_ident[EI_NIDENT]; Elf32_Half e_type; Elf32_Half e_machine; Elf32_Word e_version; Elf32_Addr e_entry; Elf32_Off e_phoff; Elf32_Off e_shoff; Elf32_Word e_flags; Elf32_Half e_ehsize; Elf32_Half e_phentsize; Elf32_Half e_phnum; Elf32_Half e_shentsize; Elf32_Half e_shnum; Elf32_Half e_shstrndx;

elf32_newehdr automatically sets the ELF_F_DIRTY bit [see elf_flag(3elf)]. A program may use elf_getident to inspect the identification bytes from a file.

For a 64-bit class file, elf64_getehdr returns a pointer to an ELF header, if one is available for the ELF descriptor elf. If no header exists for the descriptor, elf64_newehdr allocates a ``clean'' one, but it otherwise behaves the same as elf64_getehdr. It does not allocate a new header if one exists already. If no header exists (for elf_getehdr), one cannot be created (for elf_newehdr), a system error occurs, the file is not a 64-bit class file, or elf is null, both functions return a null pointer.

The header includes the following members.


unsigned char e_ident[EI_NIDENT]; Elf64_Half e_type; Elf64_Half e_machine; Elf64_Word e_version; Elf64_Addr e_entry; Elf64_Off e_phoff; Elf64_Off e_shoff; Elf64_Word e_flags; Elf64_Half e_ehsize; Elf64_Half e_phentsize; Elf64_Half e_phnum; Elf64_Half e_shentsize; Elf64_Half e_shnum; Elf64_Half e_shstrndx;

elf64_newehdr automatically sets the ELF_F_DIRTY bit [see elf_flag(3elf)]. A program may use elf_getident to inspect the identification bytes from a file.

References

Intro(3elf), elf_begin(3elf), elf_flag(3elf), elf_getident(3elf)
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004