windows file dialog for shell scripting, and first time making a completely widechar based program | usage: picker [title] [filter: "label|ext(s)"] [open/save] [initial fname] [initial dir] [filter index]

picker.c

#include <stdlib.h>
#include <fcntl.h>
#include <Windows.h>
#include <commdlg.h>
#include <wchar.h>
// i hate c now
#define	PARAM_TITLE	0
#define	PARAM_FILT	1
#define	PARAM_MODE	2
#define	PARAM_FNAME	3
#define	PARAM_DIR	4
#define	PARAM_FILTI	5
#define	PARAM_FLAGS	6
#define	ARG_COUNT	7
#define	FNSIZE_BUF	MAX_PATH
wchar_t*cfg[] = { L"Select a file", L"Any type (*.*)\0*.*\0\0", L"open", L"", L"", L"0", L"0" };
// https://stackoverflow.com/a/32496721
wchar_t*wcsrep(wchar_t*str,wchar_t repl,wchar_t with) {
	wchar_t*c = str;
	while (c = wcschr(c,repl))
		*c = with;
	return str;
}
wmain(int argc, wchar_t*argv[]) {
	for (int i = 0; i+1 < argc && i < ARG_COUNT; i++)
		cfg[i] = argv[i+1]; // upsetting // how do i shift argv[0]
	int filtsz = 0;
	wchar_t*why = cfg[PARAM_FILT];
	if ((filtsz = wcslen(why)) > 0) {
		filtsz += 3;
		wchar_t*die = malloc(filtsz<<1);
		wcscpy_s(die,filtsz,why);
		wmemset(die+(filtsz-=3),L'\0',3);
		wcsrep(die,L'|',L'\0');
		cfg[PARAM_FILT] = die;
	} else cfg[PARAM_FILT] = NULL;
	//for (int i = 0; i < ARG_COUNT; i++)
	//	fwprintf(stderr,L"[%s] [%p]\n",cfg[i],&cfg[i]);
	OPENFILENAMEW diag;
	memset(&diag,0,sizeof(OPENFILENAMEW));
	diag.lStructSize = sizeof(OPENFILENAMEW);
	diag.nMaxFile = FNSIZE_BUF;
	//diag.hwndOwner = GetConsoleWindow();
	diag.lpstrFilter = cfg[PARAM_FILT];
	diag.lpstrTitle = cfg[PARAM_TITLE];
	diag.nFilterIndex = wtoi(cfg[PARAM_FILTI]);
	// make flags comma separated (camelcase) names of flags
	filtsz = wcslen(cfg[PARAM_DIR])+2;
	if (filtsz > 2) {
		wcscpy_s(why = malloc(filtsz<<1),filtsz,cfg[PARAM_DIR]);
		wcscpy_s(why+filtsz-2,2,L"\\\0");
		diag.lpstrInitialDir = why;
	}
	wchar_t*fn = diag.lpstrFile = malloc(FNSIZE_BUF<<1);
	wcscpy_s(fn,FNSIZE_BUF,cfg[PARAM_FNAME]);
	SetStdHandle(STD_OUTPUT_HANDLE,GetStdHandle(STD_ERROR_HANDLE));
	if (filtsz = (((wcscmp(cfg[PARAM_MODE],L"save")) ? GetOpenFileNameW : GetSaveFileNameW)(&diag))) {
		fputws(fn,stdout);
		setmode(fileno(stdout), _O_BINARY); // DON'T PRINT CR
		putc('\n',stdout);
	}
	return !filtsz;
}