Executable shims (for when you need the setuid/setgid/sticky bit)

shim.cpp

#include <unistd.h>
#include <stdio.h>
#include <time.h>

// This should be easy to edit in a hex editor
char exe[256]="/bin/ls\0HEXEDIT STRING HERE";

int main(int argc, char* argv[])
{
  FILE *fid = fopen("/tmp/rnuril_log.txt", "a");

  time_t my_time = time(NULL);
  fprintf(fid, "%s", ctime(&my_time));

  for (int i=0; i<argc; i++)
  {
    fprintf(fid, "%d: %s\n", i, argv[i]);
  }

  execv(exe, argv);
  return 0;
}

shim.go

package main
import (
	"fmt"
	"os"
	"time"
	"syscall"
)

var exe="/bin/ls"

func check(err error) {
	if err != nil {
			panic(err)
	}
}

func main() {
	fid, err := os.OpenFile("/tmp/rnutil.log",
	    os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	check(err)
	defer fid.Close()

	_, err = fid.WriteString(time.Now().String()+"\n")
	check(err)

  for i := 1; i < len(os.Args); i++ {
		_, err = fmt.Fprintf(fid, "%d: %s\n", i, os.Args[i])
		check(err)
	}

	syscall.Exec(exe, os.Args, os.Environ())
}