text: #!/usr/bin/env node
  /* crc32.js (C) 2014-present SheetJS -- http://sheetjs.com */
  /* eslint-env node */
  /* vim: set ts=2 ft=javascript: */
  /*jshint node:true */
  
  var X/*:CRC32Module*/;
  try { X = require('../'); } catch(e) { X = require('crc-32'); }
  
  function help()/*:number*/ {
  [
  "usage: crc32 [options] [filename]",
  "",
  "Options:",
  "    -h, --help           output usage information",
  "    -V, --version        output the version number",
  "    -S, --seed=<n>       use integer seed as starting value (rolling CRC)",
  "    -H, --hex-seed=<h>   use hex seed as starting value (rolling CRC)",
  "    -d, --signed         print result with format `%d` (default)",
  "    -u, --unsigned       print result with format `%u`",
  "    -x, --hex            print result with format `%0.8x`",
  "    -X, --HEX            print result with format `%0.8X`",
  "    -c, --crc32c         use CRC32C (Castagnoli)",
  "    -F, --format=<s>     use specified printf format",
  "",
  "Set filename = '-' or pipe data into crc32 to read from stdin",
  "Default output mode is signed (-d)",
  ""
  ].forEach(function(l) { console.log(l); });
  	return 0;
  }
  
  function version()/*:number*/ { console.log(X.version); return 0; }
  
  var fs = require('fs');
  try { require('exit-on-epipe'); } catch(e) {}
  
  function die(msg/*:string*/, ec/*:?number*/)/*:void*/ { console.error(msg); process.exit(ec || 0); }
  
  var args/*:Array<string>*/ = process.argv.slice(2);
  var filename/*:string*/ = "";
  var fmt/*:string*/ = "";
  var seed = 0, r = 10;
  
  for(var i = 0; i < args.length; ++i) {
  	var arg = args[i];
  	if(arg.charCodeAt(0) != 45) { if(filename === "") filename = arg; continue; }
  	var m = arg.indexOf("=") == -1 ? arg : arg.substr(0, arg.indexOf("="));
  	switch(m) {
  		case "-": filename = "-"; break;
  
  		case "--help":     case "-h": process.exit(help()); break;
  		case "--version":  case "-V": process.exit(version()); break;
  
  		case "--crc32c":   case "-c": try { X = require('../crc32c'); } catch(e) { X = require('crc-32/crc32c'); } break;
  
  		case "--signed":   case "-d": fmt = "%d"; break;
  		case "--unsigned": case "-u": fmt = "%u"; break;
  		case "--hex":      case "-x": fmt = "%0.8x"; break;
  		case "--HEX":      case "-X": fmt = "%0.8X"; break;
  		case "--format":   case "-F":
  			try {
  				require("printj");
  				fmt = ((m!=arg) ? arg.substr(m.length+1) : args[++i])||"";
  			} catch(e) {
  				console.error("The `crc-32` module removed the `printj` dependency for formatting");
  				console.error("Use the `crc32-cli` module instead:");
  				console.error("    $ npx crc32-cli [options] [filename]");
  			} break;
  
  		case "--hex-seed": case "-H": r = 16;
  		/* falls through */
  		case "--seed":     case "-S":
  			seed=parseInt((m!=arg) ? arg.substr(m.length+1) : args[++i], r)||0; break;
  
  		default: die("crc32: unrecognized option `" + arg + "'", 22);
  	}
  }
  
  if(!process.stdin.isTTY) filename = filename || "-";
  if(filename.length===0) die("crc32: must specify a filename ('-' for stdin)",1);
  
  var crc32 = seed;
  // $FlowIgnore -- Writable is callable but type sig disagrees
  var writable = require('stream').Writable();
  writable._write = function(chunk, e, cb) { crc32 = X.buf(chunk, crc32); cb(); };
  writable._writev = function(chunks, cb) {
  	chunks.forEach(function(c) { crc32 = X.buf(c.chunk, crc32);});
  	cb();
  };
  writable.on('finish', function() {
  	if(fmt === "") console.log(crc32);
  	else try { console.log(require("printj").sprintf(fmt, crc32)); } catch(e) {
  		switch(fmt) {
  			case "%d": console.log(crc32); break;
  			case "%u": console.log(crc32 >>> 0); break;
  			case "%0.8x": console.log((crc32 >>> 0).toString(16).padStart(8, "0").toLowerCase()); break;
  			case "%0.8X": console.log((crc32 >>> 0).toString(16).padStart(8, "0").toUpperCase()); break;
  		}
  	}
  });
  
  if(filename === "-") process.stdin.pipe(writable);
  else if(fs.existsSync(filename)) fs.createReadStream(filename).pipe(writable);
  else die("crc32: " + filename + ": No such file or directory", 2);
  