time-to-botec

cli (4492B)

---

 #!/usr/bin/env node
 
 /**
 * @license Apache-2.0
 *
 * Copyright (c) 2018 The Stdlib Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
 'use strict';
 
 // MODULES //
 
 var proc = require( 'process' );
 var resolve = require( 'path' ).resolve;
 var readFileSync = require( '@stdlib/fs/read-file' ).sync;
 var writeFileSync = require( '@stdlib/fs/write-file' ).sync;
 var CLI = require( '@stdlib/cli/ctor' );
 var stdout = require( '@stdlib/streams/node/stdout' );
 var cwd = require( '@stdlib/process/cwd' );
 var Uint8Array = require( '@stdlib/array/uint8' );
 var Uint32Array = require( '@stdlib/array/uint32' );
 var isUint8Array = require( '@stdlib/assert/is-uint8array' );
 var isInteger = require( '@stdlib/assert/is-integer' ).isPrimitive;
 var gcopy = require( '@stdlib/blas/base/gcopy' );
 var array2buffer = require( '@stdlib/buffer/from-array' );
 var randomStream = require( './../lib' );
 
 
 // FUNCTIONS //
 
 /**
 * Callback invoked once a source stream ends.
 *
 * @private
 */
 function onEnd() {
 	// Append a trailing newline in accordance with standard POSIX behavior:
 	console.log( '' ); // eslint-disable-line no-console
 }
 
 /**
 * Attempts to load a PRNG state.
 *
 * @private
 * @param {string} filepath - absolute path to file containing PRNG state
 * @returns {(Uint32Array|Error)} PRNG state or an error
 */
 function loadState( filepath ) {
 	var state;
 	var len;
 
 	state = readFileSync( filepath );
 	if ( state instanceof Error ) {
 		return state;
 	}
 	len = state.length;
 
 	// For older Node.js environments, convert the `Buffer` to a `Uint8Array`...
 	if ( !isUint8Array( state ) ) {
 		state = gcopy( len, state, 1, new Uint8Array( len ), 1 );
 	}
 	// Create a PRNG state array "view":
 	len /= Uint32Array.BYTES_PER_ELEMENT;
 	if ( !isInteger( len ) ) {
 		return new RangeError( 'invalid option. `state` has an invalid length.' );
 	}
 	return new Uint32Array( state.buffer, state.byteOffset, len );
 }
 
 
 // MAIN //
 
 /**
 * Main execution sequence.
 *
 * @private
 * @returns {void}
 */
 function main() {
 	var stream;
 	var flags;
 	var opts;
 	var cli;
 	var dir;
 	var i;
 
 	// Create a command-line interface:
 	cli = new CLI({
 		'pkg': require( './../package.json' ),
 		'options': require( './../etc/cli_opts.json' ),
 		'help': readFileSync( resolve( __dirname, '..', 'docs', 'usage.txt' ), {
 			'encoding': 'utf8'
 		})
 	});
 
 	// Get any provided command-line options:
 	flags = cli.flags();
 	if ( flags.help || flags.version ) {
 		return;
 	}
 
 	// Get the current working directory:
 	dir = cwd();
 
 	opts = {};
 	if ( flags.iter ) {
 		opts.iter = parseInt( flags.iter, 10 );
 	}
 	if ( flags.sep ) {
 		opts.sep = flags.sep;
 	}
 	if ( flags.state ) {
 		opts.state = loadState( resolve( dir, flags.state ) );
 		if ( opts.state instanceof Error ) {
 			return onError( opts.state );
 		}
 	} else if ( flags.seed ) {
 		opts.seed = flags.seed.split( ',' );
 		for ( i = 0; i < opts.seed.length; i++ ) {
 			opts.seed[ i ] = parseInt( opts.seed[ i ], 10 );
 		}
 	}
 	if ( flags.snapshot ) {
 		proc.on( 'exit', onExit );
 	}
 
 	// Create a source stream and pipe to `stdout`:
 	stream = randomStream( opts );
 	stream.on( 'end', onEnd );
 
 	stream.pipe( stdout );
 
 	/**
 	* Callback invoked upon exiting the process.
 	*
 	* @private
 	* @param {integer} code - exit code
 	*/
 	function onExit( code ) {
 		var state;
 		var err;
 
 		// Get the current PRNG state:
 		state = stream.state;
 
 		// Create a byte array "view":
 		state = new Uint8Array( state.buffer, state.byteOffset, stream.byteLength ); // eslint-disable-line max-len
 
 		// Convert the byte array to a `Buffer` (with support for older Node.js environments):
 		state = array2buffer( state );
 
 		// Attempt to write the state to file:
 		err = writeFileSync( resolve( dir, flags.snapshot ), state );
 		if ( err ) {
 			onError( err, code || 1 );
 		}
 	}
 
 	/**
 	* Callback invoked upon encountering an error.
 	*
 	* @private
 	* @param {Error} error - error
 	* @param {integer} [code] - exit code
 	*/
 	function onError( error, code ) {
 		cli.error( error, code || 1 );
 	}
 }
 
 main();