wasm: add 21 more utilities to feat_wasm and add WASI platform stubs

Cargo.toml

@@ -180,23 +180,35 @@ feat_Tier1 = [
 # It is bit complex to deduplicate with other lists
 feat_wasm = [
   "arch",
-  "basename",
   "base32",
   "base64",
   "basenc",
+  "basename",
+  "cat",
+  "comm",
+  "cp",
+  "csplit",
   "cut",
   "date",
+  "dir",
   "dircolors",
   "dirname",
   "echo",
   "expand",
+  "expr",
   "factor",
   "false",
   "fmt",
   "fold",
+  "head",
   "join",
   "link",
+  "ln",
+  "ls",
+  "mkdir",
+  "mv",
   "nl",
+  "nproc",
   "numfmt",
   "od",
   "paste",
@@ -206,18 +218,29 @@ feat_wasm = [
   "printf",
   "ptx",
   "pwd",
+  "readlink",
+  "realpath",
+  "rm",
+  "rmdir",
   "seq",
+  "sort",
+  "split",
   "shred",
   "shuf",
   "sleep",
   "sum",
+  "tail",
   "tee",
+  "touch",
+  "tr",
   "true",
   "truncate",
+  "tsort",
   "uname",
   "unexpand",
   "uniq",
   "unlink",
+  "vdir",
   "wc",
   "yes",
   # cksum family

src/uu/cat/src/platform/mod.rs

@@ -9,6 +9,12 @@ pub use self::unix::is_unsafe_overwrite;
 #[cfg(windows)]
 pub use self::windows::is_unsafe_overwrite;
 
+// WASI: no fstat-based device/inode checks available; assume safe.
+#[cfg(target_os = "wasi")]
+pub fn is_unsafe_overwrite<I, O>(_input: &I, _output: &O) -> bool {
+    false
+}
+
 #[cfg(unix)]
 mod unix;
 

src/uu/ln/src/ln.rs

@@ -23,6 +23,13 @@ use thiserror::Error;
 use std::os::unix::fs::symlink;
 #[cfg(windows)]
 use std::os::windows::fs::{symlink_dir, symlink_file};
+#[cfg(target_os = "wasi")]
+fn symlink<P1: AsRef<Path>, P2: AsRef<Path>>(_src: P1, _dst: P2) -> std::io::Result<()> {
+    Err(std::io::Error::new(
+        std::io::ErrorKind::Unsupported,
+        "symlinks not supported on this platform",
+    ))
+}
 use std::path::{Path, PathBuf};
 use uucore::backup_control::{self, BackupMode};
 use uucore::fs::{MissingHandling, ResolveMode, canonicalize};

src/uu/split/src/platform/mod.rs

@@ -12,6 +12,34 @@ pub use self::windows::instantiate_current_writer;
 #[cfg(windows)]
 pub use self::windows::paths_refer_to_same_file;
 
+// WASI: no process spawning (filter) or device/inode comparison.
+#[cfg(target_os = "wasi")]
+pub fn paths_refer_to_same_file(_p1: &std::ffi::OsStr, _p2: &std::ffi::OsStr) -> bool {
+    false
+}
+
+#[cfg(target_os = "wasi")]
+pub fn instantiate_current_writer(
+    _filter: Option<&str>,
+    filename: &str,
+    is_new: bool,
+) -> std::io::Result<std::io::BufWriter<Box<dyn std::io::Write>>> {
+    let file = if is_new {
+        std::fs::OpenOptions::new()
+            .write(true)
+            .create(true)
+            .truncate(true)
+            .open(std::path::Path::new(filename))?
+    } else {
+        std::fs::OpenOptions::new()
+            .append(true)
+            .open(std::path::Path::new(filename))?
+    };
+    Ok(std::io::BufWriter::new(
+        Box::new(file) as Box<dyn std::io::Write>
+    ))
+}
+
 #[cfg(unix)]
 mod unix;
 

src/uu/touch/src/touch.rs

@@ -883,6 +883,10 @@ fn pathbuf_from_stdout() -> Result<PathBuf, TouchError> {
             .map_err(|e| TouchError::WindowsStdoutPathError(e.to_string()))?
             .into())
     }
+    #[cfg(target_os = "wasi")]
+    {
+        Ok(PathBuf::from("/dev/stdout"))
+    }
 }
 
 #[cfg(test)]

src/uu/tsort/src/tsort.rs

@@ -82,7 +82,6 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                 target_os = "linux",
                 target_os = "android",
                 target_os = "fuchsia",
-                target_os = "wasi",
                 target_env = "uclibc",
                 target_os = "freebsd",
             ))]