posix-io/dirent.c

/*	A part of the Windows CE C Extra Library (celibc)
	Copyright 2007-2015 PC GO Ld.

	This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
*/

#include <dirent.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

static unsigned char attribute_to_dirent_type(unsigned long int attrib) {
	//fprintf(stderr, "function: attribute_to_dirtype(0x%lx)\n", attrib);
	if(attrib & FILE_ATTRIBUTE_DIRECTORY) return DT_DIR;
	//if(attrib & FILE_ATTRIBUTE_NORMAL) return DT_REG;
	//return DT_UNKNOWN;
	return DT_REG;
}

DIR *opendir(const char *path) {
	if(!path) {
		errno = EFAULT;
		return NULL;
	}
	if(!*path) {
		errno = ENOENT;
		return NULL;
	}

	int attrib;
	size_t len = strlen(path);
	{
		wchar_t wpath[len + 1];
		mbstowcs(wpath, path, len + 1);
		attrib = GetFileAttributesW(wpath);
	}
	if(attrib == -1) return NULL;
	if(!(attrib & FILE_ATTRIBUTE_DIRECTORY)) {
		errno = ENOTDIR;
		return NULL;
	}

	DIR *r = malloc(sizeof(DIR) + len + 3);
	if(!r) {
		errno = ENOMEM;
		return NULL;
	}
	memcpy(r->dd_name, path, len);		// No need to copy the '\0'
	if(r->dd_name[len - 1] != '/' && r->dd_name[len - 1] != '\\') r->dd_name[len++] = '/';
	r->dd_name[len++] = '*';
	r->dd_name[len] = 0;

	r->dd_handle = (void *)-1;
	r->dd_stat = 0;

	r->dd_dir.d_ino = 0;
	r->dd_dir.d_reclen = sizeof r->dd_dir;
	r->dd_dir.d_namlen = 0;
	r->dd_dir.d_type = DT_UNKNOWN;
	memset(r->dd_dir.d_name, 0, FILENAME_MAX);

	return r;
}

struct dirent *readdir(DIR *dirp) {
	errno = 0;
	if(!dirp) {
		errno = EBADF;
		return NULL;
	}

	if(dirp->dd_stat < 0) {
		return NULL;
	} else if(dirp->dd_stat > 0) {
		if(FindNextFileW(dirp->dd_handle, &dirp->dd_data)) {
			dirp->dd_stat++;
		} else {
			if(GetLastError() == ERROR_NO_MORE_FILES) errno = 0;
			FindClose(dirp->dd_handle);
			dirp->dd_handle = (void *)-1;
			dirp->dd_stat = -1;
		}
	} else {
		size_t len = strlen(dirp->dd_name) + 1;
		wchar_t wname[len];
		mbstowcs(wname, dirp->dd_name, len);
		dirp->dd_handle = FindFirstFileW(wname, &dirp->dd_data);
		if(dirp->dd_handle == (void *)-1) {
			dirp->dd_stat = -1;
		} else {
			dirp->dd_stat = 1;
		}
	}

	if(dirp->dd_stat > 0) {
		//size_t len = wcslen(dirp->dd_data.cFileName) * 2;
		int len = wcstombs(dirp->dd_dir.d_name, dirp->dd_data.cFileName, FILENAME_MAX);
		//fprintf(stderr, "celibc debug: dd_data.cFileName = L\"%ls\", dd_dir.d_name = %p\"%s\"\n", dirp->dd_data.cFileName, dirp->dd_dir.d_name, dirp->dd_dir.d_name);
		if(len < 0) {
			len = 0;
			*dirp->dd_dir.d_name = 0;
		}
		dirp->dd_dir.d_namlen = len;
		dirp->dd_dir.d_type = attribute_to_dirent_type(dirp->dd_data.dwFileAttributes);
		return &dirp->dd_dir;
	}

	return NULL;
}

int closedir(DIR *dirp) {
	void *h = NULL;
	if(!dirp) {
		errno = EBADF;
		return -1;
	}
	if(dirp->dd_handle != (void *)-1) {
		h = dirp->dd_handle;
	}
	free(dirp);
	return (h && !FindClose(h)) ? -1 : 0;
}

void rewinddir(DIR *dirp) {
	if(!dirp) return;
	if(dirp->dd_handle != (void *)-1) {
		FindClose(dirp->dd_handle);
		dirp->dd_handle = (void *)-1;
	}
	dirp->dd_stat = 0;
}

long int telldir(DIR *dirp) {
	if(!dirp) {
		errno = EBADF;
		return -1;
	}
	return dirp->dd_stat;
}

void seekdir(DIR *dirp, long int offset) {
	if(!dirp) return;
	if(offset < -1) return;

	if(offset == -1) {
		if(dirp->dd_handle != (void *)-1) {
			FindClose(dirp->dd_handle);
			dirp->dd_handle = (void *)-1;
		}
		dirp->dd_stat = -1;
	} else {
		rewinddir(dirp);
		while(dirp->dd_stat < offset && readdir(dirp));
	}
}