cmd/land: add other file operations

cmd/land/process.go

@@ -101,6 +101,16 @@ func (p *Process) importer(name string) (*wasm.Module, error) {
 				Host: reflect.ValueOf(p.close),
 				Body: &wasm.FunctionBody{},
 			},
+			{
+				Sig:  &m.Types.Entries[2],
+				Host: reflect.ValueOf(isatty),
+				Body: &wasm.FunctionBody{},
+			},
+			{
+				Sig:  &m.Types.Entries[2],
+				Host: reflect.ValueOf(p.unlink),
+				Body: &wasm.FunctionBody{},
+			},
 		}
 		m.Export = &wasm.SectionExports{
 			Entries: map[string]wasm.ExportEntry{
@@ -129,6 +139,16 @@ func (p *Process) importer(name string) (*wasm.Module, error) {
 					Kind:     wasm.ExternalFunction,
 					Index:    4,
 				},
+				"isatty": {
+					FieldStr: "isatty",
+					Kind:     wasm.ExternalFunction,
+					Index:    5,
+				},
+				"unlink": {
+					FieldStr: "unlink",
+					Kind:     wasm.ExternalFunction,
+					Index:    6,
+				},
 			},
 		}
 		return m, nil
@@ -277,6 +297,20 @@ func (p *Process) close(fd int32) int32 {
 	return 0
 }
 
+func (p *Process) unlink(fnameP int32) int32 {
+	fname := string(p.readMem(fnameP))
+	err := p.fs.RemoveAll(fname)
+	if err != nil {
+		panic(err)
+	}
+
+	return 0
+}
+
+func isatty(fd int32) int32 {
+	return 0
+}
+
 func (p *Process) Main() (uint32, error) {
 	foundMain := false
 	mainID := uint32(0)

userland/src/lib/fileops.wast

@@ -4,48 +4,80 @@
  (func $open   (import "env" "open")   (param i32 i32)     (result i32))
  (func $write  (import "env" "write")  (param i32 i32 i32) (result i32))
  (func $read   (import "env" "read")   (param i32 i32 i32) (result i32))
+ (func $istty  (import "env" "isatty") (param i32)         (result i32))
+ (func $unlink (import "env" "unlink") (param i32)         (result i32))
 
+ ;; memory
  (memory $mem 1)
+
+ ;; constants
  (data (i32.const 200) "data")
  (data (i32.const 230) "Hello, world!\n")
 
- (func $main (result i32)
-       (local $fd i32)
-
+ ;; functions
+ (func $openFile (result i32)
        ;; open stdout
        (i32.const 200)
        (i32.const 42)
-       (call $open)
-
-       ;; set $fd to the file descriptor
-       (set_local $fd)
+       (call $open))
 
+ (func $writeHelloWorld (param $fd i32)
        ;; write hello world
        (get_local $fd)
        (i32.const 230)
        (i32.const 14)
        (call $write)
-       (drop)
-
-       ;; close file
-       (get_local $fd)
-       (call $close)
-
-       ;; open new file
-       (i32.const 200)
-       (i32.const 42)
-       (call $open)
-
-       ;; set $fd to the new file descriptor
-       (set_local $fd)
+       (drop))
 
+ (func $readHello (param $fd i32)
        ;; read hello world
        (get_local $fd)
        (i32.const 255)
        (i32.const 14)
        (call $read)
+       (drop))
+
+ (func $removeFile
+       (i32.const 200)
+       (call $unlink)
+       (drop))
+
+ (func $main (result i32)
+       (local $fd i32)
+
+       ;; set $fd to the file descriptor
+       (call $openFile)
+       (set_local $fd)
+
+       (get_local $fd)
+       (call $writeHelloWorld)
+       ;; close file
+       (get_local $fd)
+       (call $close)
+
+       ;; set $fd to the new file descriptor
+       (call $openFile)
+       (set_local $fd)
+
+       ;; read Hello, World
+       (get_local $fd)
+       (call $readHello)
+
+       ;; istty
+       (get_local $fd)
+       (call $istty)
        (drop)
 
+       ;; close file again
+       (get_local $fd)
+       (call $close)
+
+       ;; unlink filename
+       (call $removeFile)
+
        ;; return 0
-       )
+       (i32.const 0)
+       (set_local $fd)
+       (drop))
+
  (export "main" (func $main)))