1 files changed, 134 insertions, 0 deletions
diff --git a/os-posix.c b/os-posix.c
new file mode 100644
index 0000000..68e1d4f
--- /dev/null
+++ b/os-posix.c
@@ -0,0 +1,134 @@
+#include "os.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+
+static FsType statbuf_path_type(const struct stat *statbuf) {
+	if (S_ISREG(statbuf->st_mode))
+		return FS_FILE;
+	if (S_ISDIR(statbuf->st_mode))
+		return FS_DIRECTORY;
+	return FS_OTHER;	
+}
+
+FsType fs_path_type(char const *path) {
+	struct stat statbuf = {0};
+	if (stat(path, &statbuf) != 0)
+		return FS_NON_EXISTENT;
+	return statbuf_path_type(&statbuf);
+}
+
+FsPermission fs_path_permission(char const *path) {
+	FsPermission perm = 0;
+	if (access(path, R_OK) == 0) perm |= FS_PERMISSION_READ;
+	if (access(path, W_OK) == 0) perm |= FS_PERMISSION_WRITE;
+	return perm;
+}
+
+bool fs_file_exists(char const *path) {
+	return fs_path_type(path) == FS_FILE;
+}
+
+FsDirectoryEntry **fs_list_directory(char const *dirname) {
+	FsDirectoryEntry **entries = NULL;
+	DIR *dir = opendir(dirname);
+	if (dir) {
+		struct dirent *ent;
+		size_t nentries = 0;
+		int fd = dirfd(dir);
+		if (fd != -1) {
+			while (readdir(dir)) ++nentries;
+			rewinddir(dir);
+			entries = (FsDirectoryEntry **)calloc(nentries+1, sizeof *entries);
+			if (entries) {
+				size_t idx = 0;
+				while ((ent = readdir(dir))) {
+					char const *filename = ent->d_name;
+					size_t len = strlen(filename);
+					FsDirectoryEntry *entry = (FsDirectoryEntry *)calloc(1, sizeof *entry + len + 1);
+					if (!entry) break;
+					memcpy(entry->name, filename, len);
+					switch (ent->d_type) {
+					case DT_REG:
+						entry->type = FS_FILE;
+						break;
+					case DT_DIR:
+						entry->type = FS_DIRECTORY;
+						break;
+					case DT_LNK: // we need to dereference the link
+					case DT_UNKNOWN: { // information not available directly from dirent, we need to get it ourselves
+						struct stat statbuf = {0};
+						fstatat(fd, filename, &statbuf, 0);
+						entry->type = statbuf_path_type(&statbuf);
+					} break;
+					default:
+						entry->type = FS_OTHER;
+					}
+					if (idx < nentries) // this could actually fail if someone creates files between calculating nentries and here. 
+						entries[idx++] = entry;
+				}
+			}
+		}
+		closedir(dir);
+	}
+	return entries;
+}
+
+int fs_mkdir(char const *path) {
+	if (mkdir(path, 0755) == 0) {
+		// directory created successfully 
+		return 1;
+	} else if (errno == EEXIST) {
+		struct stat statbuf = {0};
+		if (stat(path, &statbuf) == 0) {
+			if (S_ISDIR(statbuf.st_mode)) {
+				// already exists, and it's a directory 
+				return 0;
+			} else {
+				// already exists, but not a directory 
+				return -1;
+			}
+		} else {
+			return -1;
+		}
+	} else {
+		return -1;
+	}
+}
+
+int fs_get_cwd(char *buf, size_t buflen) {
+	assert(buf && buflen);
+	if (getcwd(buf, buflen)) {
+		return 1;
+	} else if (errno == ERANGE) {
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+struct timespec time_last_modified(char const *filename) {
+	struct stat statbuf = {0};
+	stat(filename, &statbuf);
+	return statbuf.st_mtim;
+}
+
+struct timespec time_get(void) {
+	struct timespec ts = {0};
+	clock_gettime(CLOCK_REALTIME, &ts);
+	return ts;
+}
+
+void time_sleep_ns(u64 ns) {
+	struct timespec rem = {0}, req = {
+		(time_t)(ns / 1000000000),
+		(long)(ns % 1000000000)
+	};
+	
+	while (nanosleep(&req, &rem) == EINTR) // sleep interrupted by signal
+		req = rem;
+}