hare

commit 53150ab548748e824ffd119661f997979049a779
parent b2814cd779dd321ae75538f3403a0c47a381ee15
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sat,  8 Jan 2022 17:40:37 +0100

fs, os: add realpath

Signed-off-by: Drew DeVault <sir@cmpwn.com>

Diffstat:
M
fs/fs.ha
 | 
30
------------------------------
M
fs/util.ha
 | 
66
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
os/fs.ha
 | 
8
++++++++

3 files changed, 74 insertions(+), 30 deletions(-)
diff --git a/fs/fs.ha b/fs/fs.ha
@@ -220,36 +220,6 @@ export fn rmdir(fs: *fs, path: str) (void | error) = {
 	};
 };
 
-// Removes a directory, and anything in it.
-export fn rmdirall(fs: *fs, path: str) (void | error) = {
-	let it = iter(fs, path)?;
-	for (true) {
-		match (next(it)) {
-		case let ent: dirent =>
-			if (ent.name == "." || ent.name == "..") {
-				continue;
-			};
-			// XXX: This could probably be more efficient if we
-			// re-used the buffer further down the call stack.
-			let buf = alloc(path::init());
-			defer free(buf);
-			const path = path::set(buf, path, ent.name)!;
-
-			switch (ent.ftype & mode::DIR) {
-			case mode::DIR =>
-				rmdirall(fs, path)?;
-			case =>
-				remove(fs, path)?;
-			};
-		case void =>
-			break;
-		};
-	};
-	if (path != "") {
-		return rmdir(fs, path);
-	};
-};
-
 // Creates a directory and returns a subdir for it. Some filesystems support
 // doing this operation atomically, but if not, a fallback is used.
 export fn mksubdir(fs: *fs, path: str) (*fs | error) = {
diff --git a/fs/util.ha b/fs/util.ha
@@ -110,3 +110,69 @@ export fn dirents_free(d: []dirent) void = {
 		dirent_free(&d[i]);
 	};
 };
+
+// Removes a directory, and anything in it.
+export fn rmdirall(fs: *fs, path: str) (void | error) = {
+	let it = iter(fs, path)?;
+	for (true) {
+		match (next(it)) {
+		case let ent: dirent =>
+			if (ent.name == "." || ent.name == "..") {
+				continue;
+			};
+			// XXX: This could probably be more efficient if we
+			// re-used the buffer further down the call stack.
+			let buf = alloc(path::init());
+			defer free(buf);
+			const path = path::set(buf, path, ent.name)!;
+
+			switch (ent.ftype & mode::DIR) {
+			case mode::DIR =>
+				rmdirall(fs, path)?;
+			case =>
+				remove(fs, path)?;
+			};
+		case void =>
+			break;
+		};
+	};
+	if (path != "") {
+		return rmdir(fs, path);
+	};
+};
+
+// Canonicalizes a path in this filesystem by resolving all symlinks and
+// collapsing any "." or ".." path components. The return value is statically
+// allocated and will be overwritten on subsequent calls.
+export fn realpath(fs: *fs, path: str) (str | error) = {
+	static let buf = path::buffer { ... };
+	path::reset(&buf);
+
+	const iter = path::iter(path);
+	for (true) {
+		const item = match (path::next(&iter)) {
+		case let item: str =>
+			yield item;
+		case void =>
+			break;
+		};
+
+		const item = path::add(&buf, item)!;
+		const link = match (fs::readlink(fs, item)) {
+		case let link: str =>
+			yield link;
+		case wrongtype =>
+			continue;
+		case let err: error =>
+			return err;
+		};
+
+		if (!path::abs(link)) {
+			path::add(&buf, "..", link)!;
+		} else {
+			path::set(&buf, link)!;
+		};
+	};
+
+	return path::string(&buf);
+};
diff --git a/os/fs.ha b/os/fs.ha
@@ -87,3 +87,11 @@ export fn create(
 	mode: fs::mode,
 	flags: fs::flags...
 ) (io::file | fs::error) = fs::create_file(cwd, path, mode, flags...);
+
+// Canonicalizes a path in this filesystem by resolving all symlinks and
+// collapsing any "." or ".." path components.
+//
+// This function is a thin shim over [[fs::resolve]], and the return value is
+// statically allocated by [[fs::resolve]]. Thus, calls to this function or to
+// [[fs::resolve]] will overwrite the return value of either function.
+export fn realpath(path: str) (str | fs::error) = fs::realpath(cwd, path);