// shellcode="$(cat 22.bin)" ./env

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

int main(int argc, char *argv[], char *envp[])
{
#if __i386__
	const char *sys_execve = "\x0b";     // sys_execve
	const char *systemcall = "\xcd\x80"; // int $0x80
#elif __x86_64__
	const char *sys_execve = "\x3b";     // sys_execve
	const char *systemcall = "\x0f\x05"; // syscall
#else
	#error undefined arch!!!
#endif

	for(; *envp; ++envp)
		if (strstr(*envp, sys_execve) != NULL &&
		    strstr(*envp, systemcall) != NULL)
		{
			char *shellcode = strstr(*envp, "=") + 1;
			printf("shellcode[%zu] = %s\n", strlen(shellcode), shellcode);
			((void(*)())shellcode)();
		}
	printf("%s: shellcode not found!\n", argv[0]);
}