oh-my-pi/packages/coding-agent/src/tools/shell-tokenize.ts

/**
 * Conservative shell command tokenizer shared by the bash approval-pattern
 * matcher and the gh-cache invalidator.
 *
 * Splits a bash command into independent command segments, each a list of word
 * tokens. Handles single/double-quoted strings, backslash escapes, and the
 * standard operators (`;`, `&&`, `||`, `|`, `&`, `(`, `)`, newlines) as segment
 * boundaries so callers treat the pieces as independent command sequences.
 *
 * It is deliberately not a full POSIX parser — heredocs, command substitution,
 * and arithmetic expansion are out of scope; callers fall through when they
 * cannot find the structure they need.
 */
export function tokenizeShellSegments(command: string): string[][] {
	const segments: string[][] = [];
	let current: string[] = [];
	let buffer = "";
	let inSingle = false;
	let inDouble = false;
	const pushBuffer = () => {
		if (buffer.length > 0) {
			current.push(buffer);
			buffer = "";
		}
	};
	const pushSegment = () => {
		pushBuffer();
		if (current.length > 0) segments.push(current);
		current = [];
	};
	for (let i = 0; i < command.length; i++) {
		const ch = command[i];
		if (inSingle) {
			if (ch === "'") {
				inSingle = false;
				continue;
			}
			buffer += ch;
			continue;
		}
		if (inDouble) {
			if (ch === "\\" && i + 1 < command.length) {
				const next = command[i + 1];
				if (next === '"' || next === "\\" || next === "$" || next === "`") {
					buffer += next;
					i++;
					continue;
				}
			}
			if (ch === '"') {
				inDouble = false;
				continue;
			}
			buffer += ch;
			continue;
		}
		if (ch === "'") {
			inSingle = true;
			continue;
		}
		if (ch === '"') {
			inDouble = true;
			continue;
		}
		if (ch === "\\" && i + 1 < command.length) {
			buffer += command[i + 1];
			i++;
			continue;
		}
		if (ch === " " || ch === "\t") {
			pushBuffer();
			continue;
		}
		if (ch === "\n" || ch === ";" || ch === "&" || ch === "|" || ch === "(" || ch === ")") {
			pushSegment();
			// `&&`, `||` already collapsed by the segment break above.
			continue;
		}
		buffer += ch;
	}
	pushSegment();
	return segments;
}

/**
 * Returns the original text of flat shell command segments. Unlike
 * `tokenizeShellSegments`, this preserves quoting and escaping so the results
 * are safe to match against user-configured regular expressions.
 *
 * The extractor deliberately declines to split syntax whose execution context
 * cannot be determined with this small scanner (heredocs, command substitution,
 * backticks, grouping, and malformed quoting). Callers must still check the
 * complete input in that case.
 */
export function extractFlatShellCommandSegments(command: string): string[] {
	const segments: string[] = [];
	let segmentStart = 0;
	let inSingle = false;
	let inDouble = false;
	let atWordStart = true;

	const pushSegment = (end: number) => {
		const segment = command.slice(segmentStart, end).trim();
		if (segment.length > 0) segments.push(segment);
	};

	for (let i = 0; i < command.length; i++) {
		const ch = command[i];
		if (inSingle) {
			if (ch === "'") inSingle = false;
			continue;
		}
		if (inDouble) {
			if (ch === "\\") {
				if (i + 1 >= command.length) return [];
				i++;
				continue;
			}
			if (ch === '"') {
				inDouble = false;
				continue;
			}
			if (ch === "`" || (ch === "$" && command[i + 1] === "(")) return [];
			continue;
		}

		if (ch === "'") {
			inSingle = true;
			atWordStart = false;
			continue;
		}
		if (ch === '"') {
			inDouble = true;
			atWordStart = false;
			continue;
		}
		if (ch === "\\") {
			if (i + 1 >= command.length) return [];
			i++;
			atWordStart = false;
			continue;
		}
		if (
			ch === "`" ||
			ch === "(" ||
			ch === ")" ||
			(ch === "$" && command[i + 1] === "(") ||
			(ch === "$" && command[i + 1] === "{") ||
			(ch === "<" && command[i + 1] === "<") ||
			((ch === "{" || ch === "}") &&
				atWordStart &&
				(command[i + 1] === undefined || /[ \t\n;]/.test(command[i + 1])))
		) {
			return [];
		}
		if (ch === "#" && atWordStart) {
			pushSegment(i);
			const newline = command.indexOf("\n", i + 1);
			if (newline === -1) return segments;
			i = newline;
			segmentStart = newline + 1;
			atWordStart = true;
			continue;
		}
		const isRedirectionOperatorCharacter =
			ch === "|"
				? command[i - 1] === ">"
				: ch === "&"
					? command[i - 1] === ">" || command[i - 1] === "<" || command[i + 1] === ">"
					: false;
		if ((ch === "\n" || ch === ";" || ch === "|" || ch === "&") && !isRedirectionOperatorCharacter) {
			pushSegment(i);
			if ((ch === "|" || ch === "&") && command[i + 1] === ch) i++;
			segmentStart = i + 1;
			atWordStart = true;
			continue;
		}
		atWordStart = ch === " " || ch === "\t";
	}

	if (inSingle || inDouble) return [];
	pushSegment(command.length);
	return segments;
}