userspace/libc: implement alphasort, fdopendir, opendir, posix_getdents, readdir & scandir

Signed-off-by: EnderIce2 <enderice2@protonmail.com>

Userspace/libc/include/dirent.h

@@ -58,16 +58,16 @@ extern "C"
 #define DT_SHM
 #define DT_TMO
 
-	int alphasort(const struct dirent **, const struct dirent **);
+	int alphasort(const struct dirent **d1, const struct dirent **d2);
 	int closedir(DIR *dirp);
 	int dirfd(DIR *dirp);
-	DIR *fdopendir(int);
+	DIR *fdopendir(int fd);
-	DIR *opendir(const char *);
+	DIR *opendir(const char *dirname);
-	ssize_t posix_getdents(int, void *, size_t, int);
+	ssize_t posix_getdents(int fildes, void *buf, size_t nbyte, int flags);
-	struct dirent *readdir(DIR *);
+	struct dirent *readdir(DIR *dirp);
 	int readdir_r(DIR *restrict, struct dirent *restrict, struct dirent **restrict);
 	void rewinddir(DIR *);
-	int scandir(const char *, struct dirent ***, int (*)(const struct dirent *), int (*)(const struct dirent **, const struct dirent **));
+	int scandir(const char *dir, struct dirent ***namelist, int (*sel)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **));
 	void seekdir(DIR *, long);
 	long telldir(DIR *);
 

Userspace/libc/src/std/dirent.c

@@ -20,8 +20,13 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
 
-export int alphasort(const struct dirent **, const struct dirent **);
+export int alphasort(const struct dirent **d1, const struct dirent **d2)
+{
+	return strcoll((*d1)->d_name, (*d2)->d_name);
+}
 
 export int closedir(DIR *dirp)
 {
@@ -52,12 +57,122 @@ export int dirfd(DIR *dirp)
 	return __check_errno(-ENOSYS, -1);
 }
 
-export DIR *fdopendir(int);
+export DIR *fdopendir(int fd)
-export DIR *opendir(const char *);
+{
-export ssize_t posix_getdents(int, void *, size_t, int);
+	DIR *dirp = malloc(sizeof(DIR));
-export struct dirent *readdir(DIR *);
+	if (dirp == NULL)
+		return NULL;
+
+	dirp->__fd = fd;
+	return dirp;
+}
+
+export DIR *opendir(const char *dirname)
+{
+	DIR *dirp = malloc(sizeof(DIR));
+	if (dirp == NULL)
+		return NULL;
+
+	dirp->__fd = open(dirname, O_RDONLY);
+	if (dirp->__fd == -1)
+	{
+		free(dirp);
+		return NULL;
+	}
+
+	return dirp;
+}
+
+export ssize_t posix_getdents(int fildes, void *buf, size_t nbyte, int flags)
+{
+	printf("posix_getdents() is unimplemented\n");
+	return __check_errno(-ENOSYS, -1);
+}
+
+export struct dirent *readdir(DIR *dirp)
+{
+	if (!dirp)
+	{
+		errno = EBADF;
+		return NULL;
+	}
+
+	struct dirent *entry = malloc(sizeof(struct dirent));
+	if (entry == NULL)
+		return NULL;
+
+	ssize_t bytes = posix_getdents(dirp->__fd, entry, sizeof(struct dirent), 0);
+	if (bytes == -1)
+	{
+		free(entry);
+		return NULL;
+	}
+
+	return entry;
+}
+
 export int readdir_r(DIR *restrict, struct dirent *restrict, struct dirent **restrict);
 export void rewinddir(DIR *);
-export int scandir(const char *, struct dirent ***, int (*)(const struct dirent *), int (*)(const struct dirent **, const struct dirent **));
+
+export int scandir(const char *dir, struct dirent ***namelist, int (*sel)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **))
+{
+	struct dirent **entry_list = NULL;
+	struct dirent *entry;
+	DIR *dp;
+	int count = 0;
+	int capacity = 10;
+
+	dp = opendir(dir);
+	if (dp == NULL)
+		return -1;
+
+	entry_list = malloc(capacity * sizeof(struct dirent *));
+	if (entry_list == NULL)
+	{
+		closedir(dp);
+		return -1;
+	}
+
+	while ((entry = readdir(dp)) != NULL)
+	{
+		if (sel == NULL || sel(entry))
+		{
+			if (count >= capacity)
+			{
+				capacity *= 2;
+				struct dirent **new_list = realloc(entry_list, capacity * sizeof(struct dirent *));
+				if (new_list == NULL)
+				{
+					for (int i = 0; i < count; i++)
+						free(entry_list[i]);
+					free(entry_list);
+					closedir(dp);
+					return -1;
+				}
+				entry_list = new_list;
+			}
+			entry_list[count] = malloc(sizeof(struct dirent));
+			if (entry_list[count] == NULL)
+			{
+				for (int i = 0; i < count; i++)
+					free(entry_list[i]);
+				free(entry_list);
+				closedir(dp);
+				return -1;
+			}
+			memcpy(entry_list[count], entry, sizeof(struct dirent));
+			count++;
+		}
+	}
+
+	closedir(dp);
+
+	if (count > 0)
+		qsort(entry_list, count, sizeof(struct dirent *), (int (*)(const void *, const void *))compar);
+
+	*namelist = entry_list;
+	return count;
+}
+
 export void seekdir(DIR *, long);
 export long telldir(DIR *);