changep

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <elf.h>

int
main(int argc, char *argv[])
{
    int fd;
    char *buf;
    struct stat elf_stat;
    Elf32_Ehdr *elf_header;
    int size, sh_size;

    if(argc < 3)
    {
        printf( "Usage: %s <file> <address>\n", argv[0] );

        return 1;
    }

    printf( "@ File name           \t: %s .\n", argv[1] );

    if ((fd = open(argv[1],O_RDWR)) <0) /* Open file in read/write mode */
        return 2;

    if( fstat( fd, &elf_stat ) < 0 )  /* Getting size with fstat */
        return 3;

    size = elf_stat.st_size;

    printf( "@ File size           \t: %d bytes .\n", size );

    buf = (char*)malloc(sizeof(char)*size+1);

    read(fd,buf,size); /* Read whole file */

    elf_header = (Elf32_Ehdr *)buf; /* Copy the buffer into elf structure */

    printf("@ Entry point      \t: 0x%X .\n", elf_header->e_entry );

    elf_header->e_entry = strtol( argv[2], NULL, 16 );

    printf("@ New Entry point      \t: 0x%X .\n", elf_header->e_entry );

    lseek( fd, 0, SEEK_SET );

    write( fd, elf_header, size );

    close(fd);

    free(buf);
    return 0;
}