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141 lines
3.9 KiB
JavaScript

5 years ago
'use strict';
var fs = require('fs');
var LRU = require('lru-cache');
var resolveCommand = require('./resolveCommand');
var hasBrokenSpawn = require('./hasBrokenSpawn');
var isWin = process.platform === 'win32';
var shebangCache = new LRU({ max: 50, maxAge: 30 * 1000 }); // Cache just for 30sec
function readShebang(command) {
var buffer;
var fd;
var match;
var shebang;
// Check if it is in the cache first
if (shebangCache.has(command)) {
return shebangCache.get(command);
}
// Read the first 150 bytes from the file
buffer = new Buffer(150);
try {
fd = fs.openSync(command, 'r');
fs.readSync(fd, buffer, 0, 150, 0);
fs.closeSync(fd);
} catch (e) { /* empty */ }
// Check if it is a shebang
match = buffer.toString().trim().match(/#!(.+)/i);
if (match) {
shebang = match[1].replace(/\/usr\/bin\/env\s+/i, ''); // Remove /usr/bin/env
}
// Store the shebang in the cache
shebangCache.set(command, shebang);
return shebang;
}
function escapeArg(arg, quote) {
// Convert to string
arg = '' + arg;
// If we are not going to quote the argument,
// escape shell metacharacters, including double and single quotes:
if (!quote) {
arg = arg.replace(/([\(\)%!\^<>&|;,"'\s])/g, '^$1');
} else {
// Sequence of backslashes followed by a double quote:
// double up all the backslashes and escape the double quote
arg = arg.replace(/(\\*)"/g, '$1$1\\"');
// Sequence of backslashes followed by the end of the string
// (which will become a double quote later):
// double up all the backslashes
arg = arg.replace(/(\\*)$/, '$1$1');
// All other backslashes occur literally
// Quote the whole thing:
arg = '"' + arg + '"';
}
return arg;
}
function escapeCommand(command) {
// Do not escape if this command is not dangerous..
// We do this so that commands like "echo" or "ifconfig" work
// Quoting them, will make them unaccessible
return /^[a-z0-9_-]+$/i.test(command) ? command : escapeArg(command, true);
}
function requiresShell(command) {
return !/\.(?:com|exe)$/i.test(command);
}
function parse(command, args, options) {
var shebang;
var applyQuotes;
var file;
var original;
var shell;
// Normalize arguments, similar to nodejs
if (args && !Array.isArray(args)) {
options = args;
args = null;
}
args = args ? args.slice(0) : []; // Clone array to avoid changing the original
options = options || {};
original = command;
if (isWin) {
// Detect & add support for shebangs
file = resolveCommand(command);
file = file || resolveCommand(command, true);
shebang = file && readShebang(file);
shell = options.shell || hasBrokenSpawn;
if (shebang) {
args.unshift(file);
command = shebang;
shell = shell || requiresShell(resolveCommand(shebang) || resolveCommand(shebang, true));
} else {
shell = shell || requiresShell(file);
}
if (shell) {
// Escape command & arguments
applyQuotes = (command !== 'echo'); // Do not quote arguments for the special "echo" command
command = escapeCommand(command);
args = args.map(function (arg) {
return escapeArg(arg, applyQuotes);
});
// Use cmd.exe
args = ['/s', '/c', '"' + command + (args.length ? ' ' + args.join(' ') : '') + '"'];
command = process.env.comspec || 'cmd.exe';
// Tell node's spawn that the arguments are already escaped
options.windowsVerbatimArguments = true;
}
}
return {
command: command,
args: args,
options: options,
file: file,
original: original,
};
}
module.exports = parse;