C Program to test shellcode

shellcode.c

#include<stdio.h>
#include<string.h>

unsigned char code[] = \
"\x31\xc0\x50\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x89\xe3\x50\x89\xe2\x53\x89\xe1\xb0\x0b\xcd\x80";

main()
{

  printf("Shellcode Length:  %d\n", strlen(code));

	int (*ret)() = (int(*)())code;

	ret();

}

Here is another example to run x86 shellcode on x64 machine but specify the memory address where you want to load your shellcode:

# include <stdio.h>
# include <string.h>
# include <unistd.h>
# include <sys/mman.h>

# define EXEC_MEM ((void *) 0x80000000)

char shellcode[] = "{write your shellcode here}";

int main() {{
    mmap(EXEC_MEM, 0x1000, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_FIXED | MAP_PRIVATE, -1, 0);
    memcpy(EXEC_MEM, (void *)shellcode, strlen(shellcode)+1);
    (*(int (*)())EXEC_MEM)();
    return 0;
}