this is my source code
<


#include<err.h>
#include<fcntl.h>
#include<libelf.h>
#include<stdio.h>
#include<stdlib.h>
#include<sysexits.h>
#include<unistd.h>
uint32_t hash_words[] = {
0x01234567,
0x89abcdef,
0xdeadc0de
};

char string_table[] = {
/* Offset 0 */ '\0',
/* Offset 1 */ '.', 'f', 'o', 'o', '\0',
/* Offset 6 */ '.', 's', 'h', 's', 't',
'r', 't', 'a', 'b', '\0'
};

int
main(int argc , char **argv )
{

int fd;
Elf *e;
Elf_Scn *scn;
Elf_Data *data;
Elf32_Ehdr *ehdr;
Elf32_Phdr *phdr;
Elf32_Shdr *shdr;

if (argc != 2)
errx(EX_USAGE, "usage : %s file-name", argv[0]);

if (elf_version(EV_CURRENT) == EV_NONE)
errx(EX_SOFTWARE, " ELF library initialization "
"failed: %s", elf_errmsg(-1));

if ((fd = open(argv[1], O_WRONLY | O_CREAT, 0777)) < 0)
err(EX_OSERR, "open \%s\" failed", argv[1]);

if ((e = elf_begin(fd, ELF_C_WRITE, NULL)) == NULL)

errx(EX_SOFTWARE, "elf_begin() failed: %s.",
elf_errmsg(-1));

if ((ehdr = elf32_newehdr(e )) == NULL)
errx(EX_SOFTWARE, "elf32_newehdr() failed: %s.",
elf_errmsg(-1));

ehdr-> e_ident [EI_DATA] = ELFDATA2MSB;
ehdr-> e_machine = EM_PPC ; /* 32 - bit PowerPC object */
ehdr-> e_type = ET_EXEC ;

if ((phdr = elf32_newphdr(e, 1)) == NULL)
errx(EX_SOFTWARE, " elf32_newphdr() failed: %s.",
elf_errmsg(-1));

if ((scn = elf_newscn(e)) == NULL )
errx (EX_SOFTWARE, "elf_newscn() failed: %s.",
elf_errmsg(-1));

if ((data = elf_newdata(scn))== NULL)
errx(EX_SOFTWARE, "elf_newdata() failed: %s.",
elf_errmsg(-1));


data->d_align = 4;
data->d_off = 0LL;
data->d_buf = hash_words;
data->d_type = ELF_T_WORD;
data->d_size = sizeof (hash_words);
data->d_version = EV_CURRENT;

if ((shdr = elf32_getshdr(scn )) == NULL)
errx(EX_SOFTWARE, "elf32_getshdr() failed: %s.",
elf_errmsg(-1));

shdr->sh_name = 1;
shdr->sh_type = SHT_HASH;
shdr->sh_flags = SHF_ALLOC;
shdr->sh_entsize = 0;

if ((scn = elf_newscn(e)) == NULL)
errx(EX_SOFTWARE, "elf_newscn() failed : %s.",
elf_errmsg(-1));

if ((data = elf_newdata(scn)) == NULL)
errx(EX_SOFTWARE, "elf_newdata() failed : %s.",
elf_errmsg(-1));

data->d_align = 1;
data->d_buf = string_table ;
data->d_off = 0LL ;
data->d_size = sizeof(string_table);

data->d_type = ELF_T_BYTE;
data->d_version = EV_CURRENT;

if ((shdr = elf32_getshdr(scn)) == NULL)
errx(EX_SOFTWARE, "elf32_getshdr() failed: %s.",
elf_errmsg(-1));

shdr->sh_name = 6;
shdr->sh_type = SHT_STRTAB ;
shdr->sh_flags = SHF_STRINGS | SHF_ALLOC ;
shdr->sh_entsize = 0;
elf_setshstrndx(e, elf_ndxscn(scn));

if (elf_update(e, ELF_C_NULL) < 0)
errx(EX_SOFTWARE, "elf_update(NULL ) failed: %s.",
elf_errmsg(-1));

phdr->p_type = PT_PHDR ;
phdr->p_offset = ehdr-> e_phoff ;
phdr->p_filesz = elf32_fsize (ELF_T_PHDR, 1, EV_CURRENT);

(void) elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);

if (elf_update(e, ELF_C_WRITE) < 0)
errx(EX_SOFTWARE, "elf_update() failed: %s.",
elf_errmsg(-1));

(void) elf_end(e);
(void) close(fd);
exit(EX_OK);
}



after compilation i get following error

/tmp/ccstWCyE.o: In function `main':
prog5.c.text+0x3e2): undefined reference to `elf_setshstrndx'
collect2: ld returned 1 exit status

plz resolve it

Please quote the command you used to link the executable.
Did you add '-lelf' to the command? Why not?

It's a header issue, I guess :
No "elf_setshstrndx" in any Linux elf headers ? ( Line 111.)
( And no elf_setshstrndx in libelf: readelf -s libelf* | grep elf_setshstrndx )

http://comments.gmane.org/gmane.comp...ils.devel/1592
Quote 1 :
I believe this is a freebsd libelf extension that isn't in any other
libelf implementation.

Quote 2 :
No libelf I've seen has an elf_setshstrndx function. The only reason you'd
need a helper function is when the section number you need to set is
greater than 0xff00 so that you need to use SHN_XINDEX. We don't have any
helper code in libelf for setting SHN_XINDEX data, only for reading it
(e.g. elf_getshstrndx, which has changed its preferred name to
elf_getshdrstrndx.)
http://www.unix.com/man-page/all/3/elf_setshstrndx/
http://permalink.gmane.org/gmane.com...ng.dwarves/141

.

1 members found this post helpful.

Add these options too: -g -W -Wall -Wextra -pedantic -Werror