elf_flag(ELF)
elf_flag: elf_flagdata, elf_flagehdr, elf_flagelf, elf_flagphdr, elf_flagscn, elf_flagshdr --
manipulate flags
Synopsis
cc [flag . . . ] file . . . -lelf [library] . . .
#include <libelf.h>
unsigned elf_flagdata(Elf_Data data, Elf_Cmd cmd, unsigned flags);
unsigned elf_flagehdr(Elf elf, Elf_Cmd cmd, unsigned flags);
unsigned elf_flagelf(Elf elf, Elf_Cmd cmd, unsigned flags);
unsigned elf_flagphdr(Elf elf, Elf_Cmd cmd, unsigned flags);
unsigned elf_flagscn(Elf_Scn scn, Elf_Cmd cmd, unsigned flags);
unsigned elf_flagshdr(Elf_Scn scn, Elf_Cmd cmd, unsigned flags);
Description
These functions manipulate the flags associated with
various structures of an
ELF
file.
Given an
ELF
descriptor
elf,
a data descriptor
data,
or a section descriptor
scn,
the functions may set or clear the associated status bits,
returning the updated bits.
A null descriptor is allowed, to simplify error handling;
all functions return zero for this degenerate case.
cmd
may have the following values.
ELF_C_CLR-
The functions clear the bits that are asserted in
flags.
Only the non-zero bits in
flags
are cleared; zero bits do not change the status of the descriptor.
ELF_C_SET-
The functions set the bits that are asserted in
flags.
Only the non-zero bits in
flags
are set; zero bits do not change the status of the descriptor.
Descriptions of the defined
flags
bits appear below.
ELF_F_DIRTY-
When the program intends to write an
ELF
file, this flag
asserts the associated information needs to be written to
the file.
Thus, for example, a program that wished to update the
ELF
header of an existing file would call
elf_flagehdr
with this bit set in
flags
and
cmd
equal to
ELF_C_SET.
A later call to
elf_update
would write the marked header to the file.
ELF_F_LAYOUT-
Normally, the library decides how to arrange an output file.
That is, it automatically decides where to place sections,
how to align them in the file, etc.
If this bit is set for an
ELF
descriptor, the program assumes
responsibility for determining all file positions.
This bit is meaningful only for
elf_flagelf
and applies to the entire file associated with the descriptor.
When a flag bit is set for an item, it affects all the
subitems as well.
Thus, for example, if the program sets the
ELF_F_DIRTY
bit with
elf_flagelf,
the entire logical file is ``dirty.''
Examples
The following fragment shows how one might mark the
ELF
header
to be written to the output file.
ehdr = elf32_getehdr(elf);
/ dirty ehdr . . . /
elf_flagehdr(elf, ELF_C_SET, ELF_F_DIRTY);
References
Intro(ELF),
elf_end(ELF),
elf_getdata(ELF),
elf_getehdr(ELF),
elf_update(ELF)
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 - 02 June 2005