JezK
Edit File: platform-win32.js
import { execFrom, sticky } from './regex-utils'; export function quoteForCmd(text, forceQuote, caretDepth = 0) { // See the below blog post for an explanation of this function and // quoteForWin32: // eslint-disable-next-line max-len // https://blogs.msdn.microsoft.com/twistylittlepassagesallalike/2011/04/23/everyone-quotes-command-line-arguments-the-wrong-way/ if (!text.length) { return '""'; } if (/[\n\r]/.test(text)) { throw new Error("Line breaks can't be quoted on Windows"); } const caretEscape = /["%]/.test(text); text = quoteForWin32( text, forceQuote || !caretEscape && /[&()<>^|]/.test(text)); if (caretEscape) { // See Win32Context for explanation of what caretDepth is for. do { text = text.replace(/[\t "%&()<>^|]/g, '^$&'); } while (caretDepth--); } return text; } export const quoteForWin32 = (text, forceQuote) => forceQuote || /[\t "]/.test(text) ? `"${text.replace(/\\+(?=$|")/g, '$&$&').replace(/"/g, '\\"')}"` : text; export const cmdMetaChars = /[\t\n\r "%&()<>^|]/; export class Win32Context { currentScope = newScope(null) scopesByObject = new Map() argDetectState = 0 argSet = new Set() read(text) { // When cmd.exe executes a batch file, or pipes to or from one, it spawns a // second copy of itself to run the inner command. This necessitates // doubling up on carets so that escaped characters survive both cmd.exe // invocations. See: // eslint-disable-next-line max-len // https://stackoverflow.com/questions/8192318/why-does-delayed-expansion-fail-when-inside-a-piped-block-of-code#8194279 // https://ss64.com/nt/syntax-redirection.html // // Parentheses can create an additional subshell, requiring additional // escaping... it's a mess. // // So here's what we do about it: we read all unquoted text in a shell // string and put it through this tiny parser that looks for pipes, // sequence operators (&, &&, ||), redirects, and parentheses. This can't // be part of the main Puka parsing, because it can be affected by // `unquoted(...)` values provided at evaluation time. // // Then, after associating each thing that needs to be quoted with a scope // (via `mark()`), and identifying whether or not it's an argument to a // command, we can determine the depth of caret escaping required in each // scope and pass it (via `Formatter::quote()`) to `quoteForCmd()`. // // See also `ShellStringText`, which holds the logic for the previous // paragraph. const { length } = text; for (let pos = 0, match; pos < length;) { while (match = execFrom(reUnimportant, text, pos)) { if (match[2] == null) { // (not whitespace) if (match[1] != null) { // (>&) this.argDetectState = this.argDetectState === 0 ? ADS_FLAG_INITIAL_REDIRECT : 0; } else if (this.argDetectState !== ADS_FLAG_ARGS) { this.argDetectState |= ADS_FLAG_WORD; } } else { // (whitespace) if ((this.argDetectState & ADS_FLAG_WORD) !== 0) { this.argDetectState = ADS_FLAG_ARGS & ~this.argDetectState >> 1; } } pos += match[0].length; } if (pos >= length) break; if (match = execFrom(reSeqOp, text, pos)) { this.seq(); pos += match[0].length; } else { const char = text.charCodeAt(pos); if (char === CARET) { pos += 2; } else if (char === QUOTE) { // If you were foolish enough to leave a dangling quotation mark in // an unquoted span... you're likely to have bigger problems than // incorrect escaping. So we just do the simplest thing of looking for // the end quote only in this piece of text. pos += execFrom(reNotQuote, text, pos + 1)[0].length + 2; } else { if (char === OPEN_PAREN) { this.enterScope(); } else if (char === CLOSE_PAREN) { this.exitScope(); } else if (char === PIPE) { this.pipe(); } else { // (char === '<' or '>') this.argDetectState = this.argDetectState === 0 ? ADS_FLAG_INITIAL_REDIRECT : 0; } pos++; } } } } enterScope() { this.currentScope = newScope(this.currentScope); this.argDetectState = 0; } exitScope() { this.currentScope = this.currentScope.parent || (this.currentScope.parent = newScope(null)); this.argDetectState = ADS_FLAG_ARGS; } seq() { // | binds tighter than sequence operators, so the latter create new sibling // scopes for future |s to mutate. this.currentScope = newScope(this.currentScope.parent); this.argDetectState = 0; } pipe() { this.currentScope.depthDelta = 1; this.argDetectState = 0; } mark(obj) { this.scopesByObject.set(obj, this.currentScope); if (this.argDetectState === ADS_FLAG_ARGS) { this.argSet.add(obj); } else { this.argDetectState |= ADS_FLAG_WORD; } } at(obj) { const scope = this.scopesByObject.get(obj); return { depth: getDepth(scope), isArgument: this.argSet.has(obj), isNative: scope.isNative, }; } } // These flags span the Win32Context's argument detection state machine. WORD // is set when the context is inside a word that is not an argument (meaning it // is either the first word in the command, or it is the object of a redirect). // ARGS is set when the context has reached the arguments of a command. // INITIAL_REDIRECT tracks the edge case when a redirect occurs before the // first word of the command (if this flag is set, reaching the end of a word // should take the state machine back to 0 instead of setting ADS_FLAG_ARGS). const ADS_FLAG_WORD = 0x1; const ADS_FLAG_ARGS = 0x2; const ADS_FLAG_INITIAL_REDIRECT = 0x4; const getDepth = scope => scope === null ? 0 : scope.depth !== -1 ? scope.depth : scope.depth = getDepth(scope.parent) + scope.depthDelta; const newScope = parent => ({ parent, depthDelta: 0, depth: -1, isNative: false }); const CARET = '^'.charCodeAt(); const QUOTE = '"'.charCodeAt(); const OPEN_PAREN = '('.charCodeAt(); const CLOSE_PAREN = ')'.charCodeAt(); const PIPE = '|'.charCodeAt(); const reNotQuote = sticky('[^"]*'); const reSeqOp = sticky('&&?|\\|\\|'); const reUnimportant = sticky('(\\d*>&)|[^\\s"$&()<>^|]+|(\\s+)');