Singing roll up, run a bin, a penny a glitch.

runbin.c

/* 

>> How to build on Windows

* Open a VS x64 or x32 command prompt
* cl.exe runbin.c


>> Also works with Clang 6.0 within powershell...

    clang.exe -m32|64 runbin.c -o runbin.exe
    
Breakpoint insertion may or may not work given you compiler on 64bit...

*/

#include <windows.h>
#include <stdio.h>
#include <io.h>
#include <stdlib.h>
#include <malloc.h>
#include <fcntl.h>
#include <intrin.h>
 
typedef void (*FUNCPTR)(); 
 
int main(int argc, char **argv)
{
    FUNCPTR func;
    void *buf;
    int fd, len;
    int debug;
    char *filename;
    DWORD oldProtect;
 
    if (argc == 3 && strlen(argv[1]) == 2 && strncmp(argv[1], "-d", 2) == 0) {
        debug = 1;
        filename = argv[2];
    } else if (argc == 2) {
        debug = 0;
        filename = argv[1];
    } else {
        fprintf(stderr, "usage: runbin [-d] <filename>\n");
        fprintf(stderr, "  -d    insert debugger breakpoint\n");
        return 1;
    }
 
    fd = _open(filename, _O_RDONLY | _O_BINARY);
 
    if (-1 == fd) {
        perror("Error opening file");
        return 1;
    }
 
    len = _filelength(fd);
 
    if (-1 == len) {
        perror("Error getting file size");
        return 1;
    }
 
    buf = malloc(len);
 
    if (NULL == buf) {
        perror("Error allocating memory");
        return 1;
    }
 
    if (0 == VirtualProtect(buf, len, PAGE_EXECUTE_READWRITE, &oldProtect)) {
        fprintf(stderr, "Error setting memory executable: error code %d\n", GetLastError());
        return 1;
    }        
 
    if (len != _read(fd, buf, len)) {
        perror("error reading from file");
        return 1;
    }
 
    func = (FUNCPTR)buf;
 
    if (debug) {
        __debugbreak();
    }
 
    func();
 
    return 0;
}