cli (2847B)
1 #!/usr/bin/env node 2 3 /** 4 * @license Apache-2.0 5 * 6 * Copyright (c) 2021 The Stdlib Authors. 7 * 8 * Licensed under the Apache License, Version 2.0 (the "License"); 9 * you may not use this file except in compliance with the License. 10 * You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, software 15 * distributed under the License is distributed on an "AS IS" BASIS, 16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 17 * See the License for the specific language governing permissions and 18 * limitations under the License. 19 */ 20 21 'use strict'; 22 23 // MODULES // 24 25 var resolve = require( 'path' ).resolve; 26 var readFileSync = require( '@stdlib/fs/read-file' ).sync; 27 var CLI = require( '@stdlib/cli/ctor' ); 28 var stdin = require( '@stdlib/process/read-stdin' ); 29 var stdinStream = require( '@stdlib/streams/node/stdin' ); 30 var RE_EOL = require( '@stdlib/regexp/eol' ).REGEXP; 31 var isRegExpString = require( '@stdlib/assert/is-regexp-string' ); 32 var reFromString = require( '@stdlib/utils/regexp-from-string' ); 33 var substringBeforeLast = require( './../lib' ); 34 35 36 // MAIN // 37 38 /** 39 * Main execution sequence. 40 * 41 * @private 42 * @returns {void} 43 */ 44 function main() { 45 var split; 46 var flags; 47 var args; 48 var cli; 49 var str; 50 51 // Create a command-line interface: 52 cli = new CLI({ 53 'pkg': require( './../package.json' ), 54 'options': require( './../etc/cli_opts.json' ), 55 'help': readFileSync( resolve( __dirname, '..', 'docs', 'usage.txt' ), { 56 'encoding': 'utf8' 57 }) 58 }); 59 60 // Get any provided command-line options: 61 flags = cli.flags(); 62 if ( flags.help || flags.version ) { 63 return; 64 } 65 66 // Get any provided command-line arguments: 67 args = cli.args(); 68 69 if ( args.length ) { 70 str = args[ 0 ]; 71 } else { 72 // Treat an empty value as an empty string: 73 str = ''; 74 } 75 // Check if we are receiving data from `stdin`... 76 if ( !stdinStream.isTTY ) { 77 if ( flags.split ) { 78 if ( !isRegExpString( flags.split ) ) { 79 flags.split = '/'+flags.split+'/'; 80 } 81 split = reFromString( flags.split ); 82 } else { 83 split = RE_EOL; 84 } 85 return stdin( onRead ); 86 } 87 console.log( substringBeforeLast( str, flags.search ) ); // eslint-disable-line no-console 88 89 /** 90 * Callback invoked upon reading from `stdin`. 91 * 92 * @private 93 * @param {(Error|null)} error - error object 94 * @param {Buffer} data - data 95 * @returns {void} 96 */ 97 function onRead( error, data ) { 98 var lines; 99 var i; 100 if ( error ) { 101 return cli.error( error ); 102 } 103 lines = data.toString().split( split ); 104 105 // Remove any trailing separators (e.g., trailing newline)... 106 if ( lines[ lines.length-1 ] === '' ) { 107 lines.pop(); 108 } 109 for ( i = 0; i < lines.length; i++ ) { 110 console.log( substringBeforeLast( lines[ i ], flags.search ) ); // eslint-disable-line no-console 111 } 112 } 113 } 114 115 main();