sync: wip changes

package.json

@@ -1,7 +1,7 @@
 {
   "name": "webshell",
   "private": true,
-  "version": "0.0.0",
+  "version": "0.2.1",
   "type": "module",
   "scripts": {
     "dev": "vite",

src/fs/Item.ts

@@ -193,6 +193,49 @@ export class Item {
         return items.filter((item): item is Item => item !== null)
     }
 
+    /**
+     * Copies this item to the destination, replacing any existing destination.
+     */
+    async Copy(destination: Item): Promise<void> {
+        if (destination.path === this.path) {
+            throw new Error(`Cannot copy item onto itself: ${this.path}`)
+        }
+
+        if (!(await this.Exists())) {
+            throw new Error(`Cannot copy item that has not been created: ${this.path}`)
+        }
+
+        await this.load()
+
+        if (await destination.Exists()) {
+            await destination.Delete()
+        }
+
+        const childrenToCopy = this.isDirectory ? await this.List() : []
+
+        destination.isDirectory = this.isDirectory
+        destination.executable = this.executable
+        destination.data = this.isDirectory ? null : this.data
+        destination.children = []
+
+        await destination.Create()
+
+        if (this.isDirectory) {
+            await Promise.all(childrenToCopy.map(async child => {
+                const childDestinationPath = Item.NormalizePath(
+                    `${destination.GetPath()}/${child.GetName()}`
+                )
+                const destChild = child.IsDirectory()
+                    ? await Item.openDir(childDestinationPath)
+                    : await Item.open(childDestinationPath)
+
+                await child.Copy(destChild)
+            }))
+
+            await destination.load()
+        }
+    }
+
     async Delete(): Promise<void> {
         if (!(await this.Exists())) return
 

src/program/Edit.ts

@@ -0,0 +1,390 @@
+import { GetCurrentTerminal } from '../app'
+import { Item } from '../fs/Item'
+import type { SimpleStream } from '../utils/SimpleStream'
+import { Program } from './Program'
+
+type Viewport = {
+    cols: number
+    rows: number
+    headerRows: number
+    footerRows: number
+    contentHeight: number
+}
+
+type PromptState =
+    | { active: false }
+    | { active: true; label: string; value: string; handler: (value: string) => Promise<void> }
+
+export class Edit extends Program {
+    constructor() {
+        super()
+    }
+
+    async Exec(stdin: SimpleStream<string>, stdout: SimpleStream<string>, workdir: Item, args: string[]): Promise<number> {
+        if (args.length < 2) {
+            stdout.emit('edit: error: missing path argument\n')
+            return 1
+        }
+
+        const terminal = GetCurrentTerminal()
+        const resolvePath = (path: string) => Item.NormalizePath(path.startsWith('/') ? path : `${workdir.GetPath()}/${path}`)
+
+        let filePath = resolvePath(args[1])
+        let file = await Item.open(filePath, '')
+        let fileExists = await file.Exists()
+        let lines = this.normalizeLines(file.ReadData())
+        let dirty = false
+
+        let cursorLine = 0
+        let cursorCol = 0
+        let preferredCol = 0
+        let scrollLine = 0
+        let scrollCol = 0
+
+        let statusMessage = ''
+        let exitArmed = false
+
+        let promptState: PromptState = { active: false }
+
+        const getViewport = (): Viewport => {
+            const cols = Math.max(1, Math.floor(terminal.GetWidthCells()))
+            const rows = Math.max(1, Math.floor(terminal.GetHeightCells()))
+            const headerRows = rows >= 3 ? 1 : 0
+            const footerRows = rows >= 2 ? 1 : 0
+            const contentHeight = Math.max(1, rows - headerRows - footerRows)
+            return { cols, rows, headerRows, footerRows, contentHeight }
+        }
+
+        const formatLine = (text: string, width: number) => {
+            if (text.length > width)
+                return text.slice(0, width)
+            return text.padEnd(width, ' ')
+        }
+
+        const clampCursor = () => {
+            cursorLine = Math.max(0, Math.min(cursorLine, lines.length - 1))
+            const lineLength = lines[cursorLine].length
+            cursorCol = Math.max(0, Math.min(cursorCol, lineLength))
+            preferredCol = cursorCol
+        }
+
+        const ensureCursorVisible = (viewport: Viewport) => {
+            if (cursorLine < scrollLine)
+                scrollLine = cursorLine
+            if (cursorLine >= scrollLine + viewport.contentHeight)
+                scrollLine = cursorLine - viewport.contentHeight + 1
+
+            if (cursorCol < scrollCol)
+                scrollCol = cursorCol
+            if (cursorCol >= scrollCol + viewport.cols)
+                scrollCol = cursorCol - viewport.cols + 1
+
+            const maxScrollLine = Math.max(0, lines.length - viewport.contentHeight)
+            scrollLine = Math.min(scrollLine, maxScrollLine)
+            scrollCol = Math.max(0, scrollCol)
+        }
+
+        const setStatus = (message: string) => {
+            statusMessage = message
+        }
+
+        const openFile = async (path: string) => {
+            try {
+                const resolved = resolvePath(path)
+                const nextFile = await Item.open(resolved, '')
+                const exists = await nextFile.Exists()
+                const content = nextFile.ReadData()
+
+                filePath = resolved
+                file = nextFile
+                fileExists = exists
+                lines = this.normalizeLines(content)
+                dirty = false
+
+                cursorLine = 0
+                cursorCol = 0
+                preferredCol = 0
+                scrollLine = 0
+                scrollCol = 0
+
+                setStatus(exists ? `Opened ${filePath}` : `New file ${filePath}`)
+            } catch (e) {
+                setStatus(`Open failed: ${e instanceof Error ? e.message : String(e)}`)
+            }
+        }
+
+        const saveFile = async () => {
+            const data = lines.join('\n')
+
+            try {
+                if (fileExists) {
+                    await file.Write(data)
+                } else {
+                    const created = await Item.open(filePath, data)
+                    await created.Create()
+                    file = created
+                    fileExists = true
+                }
+
+                dirty = false
+                exitArmed = false
+                setStatus(`Saved ${filePath}`)
+            } catch (e) {
+                setStatus(`Save failed: ${e instanceof Error ? e.message : String(e)}`)
+            }
+        }
+
+        const startPrompt = (label: string, handler: (value: string) => Promise<void>) => {
+            promptState = { active: true, label, value: '', handler }
+        }
+
+        const render = () => {
+            const viewport = getViewport()
+            const footerRow = viewport.headerRows + viewport.contentHeight + (viewport.footerRows ? 1 : 0)
+            ensureCursorVisible(viewport)
+
+            let output = '\x1b[2J'
+
+            if (viewport.headerRows) {
+                const headerText = `EDIT - ${filePath}${dirty ? ' *' : ''}`
+                output += `\x1b[1;1H${formatLine(headerText, viewport.cols)}`
+            }
+
+            const contentStartRow = viewport.headerRows + 1
+            for (let i = 0; i < viewport.contentHeight; i++) {
+                const lineIndex = scrollLine + i
+                const lineText = lines[lineIndex] ?? ''
+                const visible = lineText.slice(scrollCol, scrollCol + viewport.cols)
+                output += `\x1b[${contentStartRow + i};1H${formatLine(visible, viewport.cols)}`
+            }
+
+            if (viewport.footerRows) {
+                const positionText = `Ln ${cursorLine + 1}, Col ${cursorCol + 1}`
+                const shortcuts = 'F2 Save  F3 Open  F10 Exit'
+                const footerText = promptState.active
+                    ? `${promptState.label}${promptState.value}`
+                    : `${shortcuts}  ${positionText}${statusMessage ? `  ${statusMessage}` : ''}`
+                output += `\x1b[${footerRow};1H${formatLine(footerText, viewport.cols)}`
+            }
+
+                if (promptState.active) {
+                const cursorRow = footerRow
+                    const cursorColPos = Math.min(viewport.cols, promptState.label.length + promptState.value.length + 1)
+                output += `\x1b[${cursorRow};${cursorColPos}H`
+            } else {
+                const cursorRow = contentStartRow + (cursorLine - scrollLine)
+                const cursorColPos = 1 + (cursorCol - scrollCol)
+                output += `\x1b[${cursorRow};${cursorColPos}H`
+            }
+
+            stdout.emit(output)
+        }
+
+        render()
+
+        while (true) {
+            const key = await stdin.wait()
+
+            if (promptState.active) {
+                if (key === 'Escape') {
+                    promptState = { active: false }
+                    setStatus('Canceled')
+                    render()
+                    continue
+                }
+
+                if (key === 'Enter') {
+                    const { handler } = promptState
+                    const value = promptState.value.trim()
+                    promptState = { active: false }
+
+                    if (value.length > 0) {
+                        await handler(value)
+                    } else {
+                        setStatus('Canceled')
+                    }
+
+                    render()
+                    continue
+                }
+
+                if (key === 'Backspace') {
+                    const nextValue: string = promptState.value.slice(0, -1)
+                    promptState = {
+                        active: true,
+                        label: promptState.label,
+                        value: nextValue,
+                        handler: promptState.handler,
+                    }
+                    render()
+                    continue
+                }
+
+                if (key.length === 1) {
+                    const nextValue: string = promptState.value + key
+                    promptState = {
+                        active: true,
+                        label: promptState.label,
+                        value: nextValue,
+                        handler: promptState.handler,
+                    }
+                    render()
+                }
+
+                continue
+            }
+
+            if (exitArmed && key !== 'F10')
+                exitArmed = false
+
+            switch (key) {
+                case 'F2':
+                    await saveFile()
+                    render()
+                    continue
+                case 'F3':
+                    startPrompt('Open: ', openFile)
+                    render()
+                    continue
+                case 'F10':
+                    if (dirty && !exitArmed) {
+                        exitArmed = true
+                        setStatus('Unsaved changes. Press F10 again to exit.')
+                        render()
+                        continue
+                    }
+                    stdout.emit('\x1b[2J\x1b[H')
+                    return 0
+                case 'ArrowLeft':
+                    if (cursorCol > 0) {
+                        cursorCol -= 1
+                    } else if (cursorLine > 0) {
+                        cursorLine -= 1
+                        cursorCol = lines[cursorLine].length
+                    }
+                    preferredCol = cursorCol
+                    render()
+                    continue
+                case 'ArrowRight': {
+                    const lineLength = lines[cursorLine].length
+                    if (cursorCol < lineLength) {
+                        cursorCol += 1
+                    } else if (cursorLine < lines.length - 1) {
+                        cursorLine += 1
+                        cursorCol = 0
+                    }
+                    preferredCol = cursorCol
+                    render()
+                    continue
+                }
+                case 'ArrowUp':
+                    cursorLine = Math.max(0, cursorLine - 1)
+                    cursorCol = Math.min(preferredCol, lines[cursorLine].length)
+                    render()
+                    continue
+                case 'ArrowDown':
+                    cursorLine = Math.min(lines.length - 1, cursorLine + 1)
+                    cursorCol = Math.min(preferredCol, lines[cursorLine].length)
+                    render()
+                    continue
+                case 'Home':
+                    cursorCol = 0
+                    preferredCol = cursorCol
+                    render()
+                    continue
+                case 'End':
+                    cursorCol = lines[cursorLine].length
+                    preferredCol = cursorCol
+                    render()
+                    continue
+                case 'PageUp': {
+                    const viewport = getViewport()
+                    cursorLine = Math.max(0, cursorLine - viewport.contentHeight)
+                    cursorCol = Math.min(preferredCol, lines[cursorLine].length)
+                    render()
+                    continue
+                }
+                case 'PageDown': {
+                    const viewport = getViewport()
+                    cursorLine = Math.min(lines.length - 1, cursorLine + viewport.contentHeight)
+                    cursorCol = Math.min(preferredCol, lines[cursorLine].length)
+                    render()
+                    continue
+                }
+                case 'Backspace':
+                    if (cursorCol > 0) {
+                        const line = lines[cursorLine]
+                        lines[cursorLine] = line.slice(0, cursorCol - 1) + line.slice(cursorCol)
+                        cursorCol -= 1
+                        preferredCol = cursorCol
+                        dirty = true
+                    } else if (cursorLine > 0) {
+                        const current = lines[cursorLine]
+                        cursorLine -= 1
+                        cursorCol = lines[cursorLine].length
+                        lines[cursorLine] += current
+                        lines.splice(cursorLine + 1, 1)
+                        preferredCol = cursorCol
+                        dirty = true
+                    }
+                    render()
+                    continue
+                case 'Delete': {
+                    const line = lines[cursorLine]
+                    if (cursorCol < line.length) {
+                        lines[cursorLine] = line.slice(0, cursorCol) + line.slice(cursorCol + 1)
+                        dirty = true
+                    } else if (cursorLine < lines.length - 1) {
+                        lines[cursorLine] = line + lines[cursorLine + 1]
+                        lines.splice(cursorLine + 1, 1)
+                        dirty = true
+                    }
+                    render()
+                    continue
+                }
+                case 'Enter': {
+                    const line = lines[cursorLine]
+                    const before = line.slice(0, cursorCol)
+                    const after = line.slice(cursorCol)
+                    lines[cursorLine] = before
+                    lines.splice(cursorLine + 1, 0, after)
+                    cursorLine += 1
+                    cursorCol = 0
+                    preferredCol = 0
+                    dirty = true
+                    render()
+                    continue
+                }
+                case 'Tab':
+                    lines[cursorLine] = this.insertText(lines[cursorLine], cursorCol, '    ')
+                    cursorCol += 4
+                    preferredCol = cursorCol
+                    dirty = true
+                    render()
+                    continue
+            }
+
+            if (key.length === 1) {
+                lines[cursorLine] = this.insertText(lines[cursorLine], cursorCol, key)
+                cursorCol += 1
+                preferredCol = cursorCol
+                dirty = true
+                render()
+                continue
+            }
+
+            clampCursor()
+            render()
+        }
+    }
+
+    private normalizeLines(content: string | null): string[] {
+        const normalized = (content ?? '').replace(/\r\n/g, '\n').replace(/\r/g, '\n')
+        const lines = normalized.split('\n')
+        return lines.length === 0 ? [''] : lines
+    }
+
+    private insertText(line: string, index: number, text: string): string {
+        return line.slice(0, index) + text + line.slice(index)
+    }
+}

src/program/Mv.ts

@@ -0,0 +1,45 @@
+import { Item } from '../fs/Item'
+import type { SimpleStream } from '../utils/SimpleStream'
+import { Program } from './Program'
+
+export class Mv extends Program {
+    constructor() {
+        super()
+    }
+
+    async Exec(_: SimpleStream<string>, stdout: SimpleStream<string>, workdir: Item, args: string[]): Promise<number> {
+        if (args.length < 3) {
+            stdout.emit("mv: error: missing the first and/or second path arguments\n")
+            return 1
+        }
+
+        let item1: Item
+        let item2: Item
+
+        try {
+            item1 = await Item.openDir(Item.NormalizePath(args[1].startsWith('/') ? args[1] : `${workdir.GetPath()}/${args[1]}`))
+            item2 = await Item.openDir(Item.NormalizePath(args[2].startsWith('/') ? args[2] : `${workdir.GetPath()}/${args[2]}`))
+        } catch {
+            item1 = await Item.open(Item.NormalizePath(args[1].startsWith('/') ? args[1] : `${workdir.GetPath()}/${args[1]}`))
+            item2 = await Item.open(Item.NormalizePath(args[2].startsWith('/') ? args[2] : `${workdir.GetPath()}/${args[2]}`))
+        }
+
+        if (await item1.Exists()) {
+            stdout.emit(`mv: error: source directory ${item1.GetPath()} does not exist.\n`)
+            return 2
+        }
+
+        if (await item2.Exists()) {
+            stdout.emit(`mv: error: destination directory ${item2.GetPath()} already exists.\n`)
+            return 2
+        }
+
+        await item2.Create()
+        await item1.Copy(item2)
+        await item1.Delete()
+
+        stdout.emit(`-> moved ${item1.GetPath()} -> ${item2.GetPath()}\n`)
+
+        return 0
+    }
+}

src/shell/wush/Environment.ts

@@ -6,11 +6,11 @@ export class Environment {
     private variables: Record<string, string> = {}
     private aliases: Record<string, string> = {}
 
-    SetVariable(name: string, value: string | null): void {
+    SetVariable(name: string, value: any | null): void {
         if (value === null) {
             // remove the variable if value is null
             delete this.variables[name]
-        } else this.variables[name] = value
+        } else this.variables[name] = String(value)
     }
 
     GetVariable(name: string): string | null {

src/shell/wush/InputParser.ts

@@ -0,0 +1,13 @@
+/**
+ * Wush input parser
+ * Provides necessary parsing functions
+ */
+export class InputParser {
+    static Tokenize(input: string) {
+
+    }
+
+    static Parse(tokens: string[]) {
+
+    }
+}

src/shell/wush/Wush.ts

@@ -27,6 +27,8 @@ import { Printf } from '../../program/Printf'
 import { Pwd } from '../../program/Pwd'
 import { Environment } from './Environment'
 import { InputManager } from './InputManager'
+import { Edit } from '../../program/Edit'
+import { Mv } from '../../program/Mv'
 
 export class Wush extends Shell {
     public readonly Version = "0.3.2"
@@ -38,7 +40,6 @@ export class Wush extends Shell {
     _promptStart: CursorPosition = { col: 0, row: 0 }
 
     private inputManager: InputManager
-    // @ts-ignore unused for now
     private environment: Environment
 
     // exec stuff
@@ -93,11 +94,21 @@ export class Wush extends Shell {
         this.programs['pwd'] = new Pwd()
         this.programs['cd'] = new Cd(this)
         this.programs['printf'] = new Printf()
+        this.programs['edit'] = new Edit()
+        this.programs['mv'] = new Mv()
+
+        // reset exit code
+        this.SetExitCode(0)
 
         // initial prompt
         this.Prompt()
     }
 
+    SetExitCode(code: number): void {
+        this.execExitCode = code
+        this.environment.SetVariable("status", code)
+    }
+
     HasRunningProgram(): boolean {
         return this.execExitCode === -1
     }
@@ -122,7 +133,7 @@ export class Wush extends Shell {
         return new Promise<void>(resolve => {
             this.programs[name].Exec(this.stdin, this.stdout, this.workingDirectory, args)
                 .then(code => {
-                    this.execExitCode = code != -1 ? code : -2
+                    this.SetExitCode(code != -1 ? code : -2)
                     resolve()
                 })
                 .catch((e) => {
@@ -134,7 +145,7 @@ export class Wush extends Shell {
                     // check if the exec actually exited with an exit code
                     // and if not, set it to -2 to indicate that it didn't exit with a valid code
                     if (this.execExitCode === -1)
-                        this.execExitCode = -2
+                        this.SetExitCode(-2)
 
                     // this.terminal.Write(`The program exited with exit code ${this.execExitCode}.`)
                     resolve()
@@ -234,19 +245,33 @@ export class Wush extends Shell {
         this._bufferPos = 0
     }
 
-    // takes the prompt buffer, parses it and executes the contents
+    /**
+     * Takes the prompt buffer, parses it and executes the contents
+     */
     async ExecuteLineBuffer(data?: string) {
-        type OperatorToken = '&&' | '||' | '|' | ';'
+        type OperatorToken = '&&' | '||' | '|' | ';' | '>' | '>>' | '<'
         type Token = { type: 'word'; value: string } | { type: 'operator'; value: OperatorToken }
         type ParsedCommand = {
             args: string[]
             stdin: null | SimpleStream<string>
             stdout: null | SimpleStream<string>
+            stdinPath: string | null
+            stdoutPath: string | null
+            stdoutAppend: boolean
         }
         type ParsedPipeline = { commands: ParsedCommand[] }
         type ParsedListItem = { pipeline: ParsedPipeline; operator: '&&' | '||' | ';' | null }
 
-        // splits the buffer into processable pieces (tokens)
+        // environment variable helpers
+        /**
+         * @returns value of the variable, empty string otherwise
+         */
+        const resolveVariable = (name: string): string => this.environment.GetVariable(name) ?? ''
+        const isValidVarNameChar = (char: string) => /[A-Za-z0-9_]/.test(char)
+
+        /**
+         * splits the buffer into smaller processable pieces (tokens)
+         */
         const tokenize = (text: string): { tokens: Token[]; error: string | null } => {
             const tokens: Token[] = []
 
@@ -258,7 +283,7 @@ export class Wush extends Shell {
             let escapeNext = false
 
             /**
-             * adds a new word to the token buffer
+             * adds a new plain string to the token buffer
              */
             const pushWord = () => {
                 if (!wordStarted)
@@ -271,6 +296,69 @@ export class Wush extends Shell {
                 wordStarted = false
             }
 
+            // reads environment variable tokens
+            const readVariable = (index: number): {
+                value: string
+                nextIndex: number
+                error: string | null
+                expanded: boolean
+            } => {
+                if (index + 1 >= text.length)
+                    return { value: '$', nextIndex: index, error: null, expanded: false }
+
+                const next = text[index + 1]
+                if (next === '{') {
+                    let end = index + 2
+                    while (end < text.length && text[end] !== '}')
+                        end++
+
+                    if (end >= text.length)
+                        return { value: '', nextIndex: text.length - 1, error: 'unterminated variable expansion', expanded: true }
+
+                    const name = text.slice(index + 2, end)
+                    if (name.length === 0)
+                        return { value: '', nextIndex: end, error: 'empty variable name', expanded: true }
+
+                    return { value: resolveVariable(name), nextIndex: end, error: null, expanded: true }
+                }
+
+                if (isValidVarNameChar(next)) {
+                    let end = index + 1
+                    while (end + 1 < text.length && isValidVarNameChar(text[end + 1]))
+                        end++
+
+                    const name = text.slice(index + 1, end + 1)
+                    return { value: resolveVariable(name), nextIndex: end, error: null, expanded: true }
+                }
+
+                return { value: '$', nextIndex: index, error: null, expanded: false }
+            }
+
+            const appendExpandedValue = (value: string, split: boolean, preserveEmpty: boolean) => {
+                if (value.length === 0) {
+                    if (preserveEmpty)
+                        wordStarted = true
+
+                    return
+                }
+
+                if (!split) {
+                    current += value
+                    wordStarted = true
+                    return
+                }
+
+                for (const char of value) {
+                    if (char === ' ' || char === '\t') {
+                        pushWord()
+                        continue
+                    }
+
+                    current += char
+                    wordStarted = true
+                }
+            }
+
             // iterates over the provided text buffer
             for (let i = 0; i < text.length; i++) {
                 const char = text[i]
@@ -307,6 +395,18 @@ export class Wush extends Shell {
                         current += text[i + 1]
                         i++
                         wordStarted = true
+                    } else if (char === '$') {
+                        const { value, nextIndex, error, expanded } = readVariable(i)
+                        if (error)
+                            return { tokens: [], error }
+
+                        if (expanded) {
+                            appendExpandedValue(value, false, true)
+                            i = nextIndex
+                        } else {
+                            current += char
+                            wordStarted = true
+                        }
                     } else {
                         current += char
                         wordStarted = true
@@ -338,6 +438,22 @@ export class Wush extends Shell {
                     continue
                 }
 
+                if (char === '$') {
+                    const { value, nextIndex, error, expanded } = readVariable(i)
+                    if (error)
+                        return { tokens: [], error }
+
+                    if (expanded) {
+                        appendExpandedValue(value, true, false)
+                        i = nextIndex
+                    } else {
+                        current += char
+                        wordStarted = true
+                    }
+
+                    continue
+                }
+
                 if (char === ' ' || char === '\t') {
                     pushWord()
                     continue
@@ -358,6 +474,23 @@ export class Wush extends Shell {
                     continue
                 }
 
+                if (char === '>') {
+                    pushWord()
+                    if (text[i + 1] === '>') {
+                        tokens.push({ type: 'operator', value: '>>' })
+                        i++
+                    } else {
+                        tokens.push({ type: 'operator', value: '>' })
+                    }
+                    continue
+                }
+
+                if (char === '<') {
+                    pushWord()
+                    tokens.push({ type: 'operator', value: '<' })
+                    continue
+                }
+
                 if (char === '|') {
                     pushWord()
                     if (text[i + 1] === '|') {
@@ -402,6 +535,10 @@ export class Wush extends Shell {
             let currentArgs: string[] = []
             let currentPipeline: ParsedCommand[] = []
             let expectCommand = false
+            let expectRedirect: 'stdin' | 'stdout' | 'append' | null = null
+            let currentStdinPath: string | null = null
+            let currentStdoutPath: string | null = null
+            let currentStdoutAppend = false
 
             const pushCommand = () => {
                 if (currentArgs.length === 0)
@@ -411,8 +548,14 @@ export class Wush extends Shell {
                     args: currentArgs,
                     stdin: null,
                     stdout: null,
+                    stdinPath: currentStdinPath,
+                    stdoutPath: currentStdoutPath,
+                    stdoutAppend: currentStdoutAppend,
                 })
                 currentArgs = []
+                currentStdinPath = null
+                currentStdoutPath = null
+                currentStdoutAppend = false
                 return true
             }
 
@@ -427,12 +570,43 @@ export class Wush extends Shell {
 
             for (const token of tokens) {
                 if (token.type === 'word') {
+                    if (expectRedirect) {
+                        if (expectRedirect === 'stdin') {
+                            currentStdinPath = token.value
+                        } else {
+                            currentStdoutPath = token.value
+                            currentStdoutAppend = expectRedirect === 'append'
+                        }
+
+                        expectRedirect = null
+                        expectCommand = false
+                        continue
+                    }
+
                     currentArgs.push(token.value)
                     expectCommand = false
                     continue
                 }
 
+                if (expectRedirect)
+                    return { list: [], error: 'expected redirection target' }
+
+                if (token.value === '>' || token.value === '>>' || token.value === '<') {
+                    if (currentArgs.length === 0)
+                        return { list: [], error: `unexpected "${token.value}" operator` }
+
+                    expectRedirect = token.value === '<'
+                        ? 'stdin'
+                        : token.value === '>>'
+                            ? 'append'
+                            : 'stdout'
+                    continue
+                }
+
                 if (token.value === '|') {
+                    if (currentStdoutPath)
+                        return { list: [], error: 'unexpected "|" operator after redirection' }
+
                     if (!pushCommand())
                         return { list: [], error: 'unexpected "|" operator' }
 
@@ -449,6 +623,9 @@ export class Wush extends Shell {
             if (expectCommand)
                 return { list: [], error: 'unexpected end of input' }
 
+            if (expectRedirect)
+                return { list: [], error: 'expected redirection target' }
+
             if (currentArgs.length > 0)
                 pushCommand()
 
@@ -494,32 +671,170 @@ export class Wush extends Shell {
             return
         }
 
-        if (list.some(item => item.pipeline.commands.length > 1)) {
+        const resolvePath = (path: string) => Item.NormalizePath(
-            this.terminal.Write(`wush: error: pipes are not supported yet`)
+            path.startsWith('/') ? path : `${this.workingDirectory.GetPath()}/${path}`
-            this.terminal.MoveCursor(0, 1, { x: true, y: false })
+        )
 
-            this.Prompt()
+        const openInputRedirect = async (path: string) => {
-            return
+            const resolved = resolvePath(path)
+            const item = await Item.open(resolved)
+
+            if (!(await item.Exists()))
+                throw new Error(`input file ${resolved} doesn't exist`)
+
+            if (item.IsDirectory())
+                throw new Error(`input file ${resolved} is a directory`)
+
+            return { stream: new SimpleStream<string>(), data: item.ReadData() ?? '' }
+        }
+
+        const openOutputRedirect = async (path: string, append: boolean) => {
+            const resolved = resolvePath(path)
+            const item = await Item.open(resolved)
+
+            if (!(await item.Exists()))
+                await item.Create()
+
+            if (item.IsDirectory())
+                throw new Error(`output path ${resolved} is a directory`)
+
+            if (!append)
+                await item.Write('')
+
+            const stream = new SimpleStream<string>()
+            let writeQueue = Promise.resolve()
+            const listener = (data: string) => {
+                writeQueue = writeQueue.then(() => item.Append(data))
+            }
+            stream.on(listener)
+
+            return {
+                stream,
+                finish: () => writeQueue,
+                teardown: () => stream.off(listener),
+            }
+        }
+
+        const setupPipelineStreams = async (pipeline: ParsedPipeline) => {
+            const teardown: Array<() => void> = []
+            const stdins: SimpleStream<string>[] = []
+            const stdouts: SimpleStream<string>[] = []
+            const finishers: Array<() => Promise<void>> = []
+            const inputFeeds: Array<{ stream: SimpleStream<string>; data: string }> = []
+
+            try {
+                for (const [index, command] of pipeline.commands.entries()) {
+                    let stdin: SimpleStream<string>
+                    let stdout: SimpleStream<string>
+
+                    if (command.stdinPath) {
+                        if (index !== 0)
+                            throw new Error('input redirection is only supported on the first command in a pipeline')
+
+                        const { stream, data } = await openInputRedirect(command.stdinPath)
+                        stdin = stream
+                        inputFeeds.push({ stream, data })
+                    } else {
+                        stdin = index === 0 ? this.stdin : new SimpleStream<string>()
+                    }
+
+                    if (command.stdoutPath) {
+                        if (index !== pipeline.commands.length - 1)
+                            throw new Error('output redirection is only supported on the last command in a pipeline')
+
+                        const { stream, finish, teardown: remove } = await openOutputRedirect(
+                            command.stdoutPath,
+                            command.stdoutAppend
+                        )
+                        stdout = stream
+                        finishers.push(finish)
+                        teardown.push(remove)
+                    } else {
+                        stdout = index === pipeline.commands.length - 1 ? this.stdout : new SimpleStream<string>()
+                    }
+
+                    command.stdin = stdin
+                    command.stdout = stdout
+
+                    stdins.push(stdin)
+                    stdouts.push(stdout)
+                }
+
+                for (let i = 0; i < pipeline.commands.length - 1; i++) {
+                    if (pipeline.commands[i].stdoutPath)
+                        throw new Error('cannot pipe a command with output redirection')
+
+                    if (pipeline.commands[i + 1].stdinPath)
+                        throw new Error('cannot pipe into a command with input redirection')
+
+                    const listener = (data: string) => stdins[i + 1].emit(data)
+                    stdouts[i].on(listener)
+                    teardown.push(() => stdouts[i].off(listener))
+                }
+
+                return { stdins, stdouts, teardown, finishers, inputFeeds }
+            } catch (e) {
+                teardown.forEach(remove => remove())
+                throw e
+            }
+        }
+
+        const executePipeline = async (pipeline: ParsedPipeline): Promise<number> => {
+            const missing = pipeline.commands.find(command => !(this.programs[command.args[0]] instanceof Program))
+            if (missing) {
+                const name = missing.args[0]
+
+                if (name.length !== 0) {
+                    this.terminal.Write(`wush: error: unknown command: ${name}.`)
+                    this.terminal.MoveCursor(0, 1, { x: true, y: false })
+                    return 127
+                }
+
+                return 0
+            }
+
+            let setup: Awaited<ReturnType<typeof setupPipelineStreams>>
+            try {
+                setup = await setupPipelineStreams(pipeline)
+            } catch (e) {
+                const message = e instanceof Error ? e.message : String(e)
+                this.terminal.Write(`wush: error: ${message}`)
+                this.terminal.MoveCursor(0, 1, { x: true, y: false })
+                return 1
+            }
+
+            try {
+                const exitCodes = await Promise.all(pipeline.commands.map(async (command, index) => {
+                    try {
+                        return await this.programs[command.args[0]].Exec(
+                            setup.stdins[index],
+                            setup.stdouts[index],
+                            this.workingDirectory,
+                            command.args
+                        )
+                    } catch (e) {
+                        this.WriteEscapedString(`wush: command ${command.args[0]} exited with the following exception\n`)
+                        this.WriteEscapedString(`    | ${String(e)}\n`)
+                        return -2
+                    }
+                }))
+
+                setup.inputFeeds.forEach(feed => {
+                    queueMicrotask(() => feed.stream.emit(feed.data))
+                })
+
+                await Promise.all(setup.finishers.map(finish => finish()))
+
+                const lastExitCode = exitCodes[exitCodes.length - 1]
+                return lastExitCode !== -1 ? lastExitCode : -2
+            } finally {
+                setup.teardown.forEach(remove => remove())
+            }
         }
 
         for (const item of list) {
-            const command = item.pipeline.commands[0]
+            this.SetExitCode(-1)
-
+            this.SetExitCode(await executePipeline(item.pipeline))
-            this.execExitCode = -1
-
-            if (this.programs[command.args[0]] instanceof Program) {
-                await this.ExecuteProgram(command.args[0], command.args)
-            } else {
-                this.execExitCode = 0
-
-                // don't print anything if there are no arguments
-                if (command.args[0].length !== 0) {
-                    this.terminal.Write(`wush: error: unknown command: ${command.args[0]}.`)
-                    this.terminal.MoveCursor(0, 1, { x: true, y: false })
-
-                    this.execExitCode = 127
-                }
-            }
         }
 
         this.Prompt()