HP-UX Reference (11i v2 07/12) - 3 Library Functions A-M (vol 6)

elf_rawﬁle(3E) elf_rawﬁle(3E)

NAME

elf_rawﬁle - retrieve uninterpreted ﬁle contents

SYNOPSIS

cc [ﬂag... ] ﬁle...

-lelf [library] ...

#include <libelf.h>

char *elf_rawfile(Elf *elf, size_t *ptr);

DESCRIPTION

elf_rawfile returns a pointer to an uninterpreted byte image of the ﬁle. This function should be used

only to retrieve a ﬁle being read. For example, a program might use

elf_rawfile to retrieve the bytes

for an archive member.

A program may not close or disable (see elf_cntl(3E)) the ﬁle descriptor associated with elf before the initial

call to

elf_rawfile , because elf_rawfile might have to read the data from the ﬁle if it does not

already have the original bytes in memory. Generally, this function is more efﬁcient for unknown ﬁle types

than for object ﬁles. The library implicitly translates object ﬁles in memory, while it leaves unknown ﬁles

unmodiﬁed. Thus asking for the uninterpreted image of an object ﬁle may create a duplicate copy in

memory.

elf_rawdata (see elf_getdata(3E)) is a related function, providing access to sections within a ﬁle.

If ptr is non-null, the library also stores the ﬁle’s size, in bytes, in the location to which ptr points. If no

data is present, elf is null, or an error occurs, the return value is a null pointer, with zero optionally stored

through ptr.

NOTICES

A program that uses

elf_rawfile and that also interprets the same ﬁle as an object ﬁle potentially has

two copies of the bytes in memory. If such a program requests the raw image ﬁrst, before it asks for

translated information (through such functions as elf_getehdr, elf_getdata , and so on), the library

‘‘freezes’’ its original memory copy for the raw image. It then uses this frozen copy as the source for creat-

ing translated objects, without reading the ﬁle again. Consequently, the application should view the raw

ﬁle image returned by elf_rawfile as a read-only buffer, unless it wants to alter its own view of data

subsequently translated. In any case, the application may alter the translated objects without changing

bytes visible in the raw image.

Multiple calls to elf_rawfile with the same ELF descriptor return the same value; the library does not

create duplicate copies of the ﬁle.