基于python实现的区块链的供应链金融平台（含实验报告+源码）

yargs ======== Yargs be a node.js library fer hearties tryin' ter parse optstrings. With yargs, ye be havin' a map that leads straight to yer treasure! Treasure of course, being a simple option hash. [![Build Status][travis-image]][travis-url] [![Dependency Status][gemnasium-image]][gemnasium-url] [![Coverage Status][coveralls-image]][coveralls-url] [![NPM version][npm-image]][npm-url] [![Windows Tests][windows-image]][windows-url] [![js-standard-style][standard-image]][standard-url] [![standard-version][standard-version-image]][standard-version-url] > Yargs is the official successor to optimist. Please feel free to submit issues and pull requests. If you'd like to contribute and don't know where to start, have a look at [the issue list](https://github.com/yargs/yargs/issues) :) examples ======== With yargs, the options be just a hash! ------------------------------------------------------------------- plunder.js: ````javascript #!/usr/bin/env node var argv = require('yargs').argv; if (argv.ships > 3 && argv.distance < 53.5) { console.log('Plunder more riffiwobbles!'); } else { console.log('Retreat from the xupptumblers!'); } ```` *** $ ./plunder.js --ships=4 --distance=22 Plunder more riffiwobbles! $ ./plunder.js --ships 12 --distance 98.7 Retreat from the xupptumblers!  But don't walk the plank just yet! There be more! You can do short options: ------------------------------------------------- short.js: ````javascript #!/usr/bin/env node var argv = require('yargs').argv; console.log('(%d,%d)', argv.x, argv.y); ```` *** $ ./short.js -x 10 -y 21 (10,21) And booleans, both long, short, and even grouped: ---------------------------------- bool.js: ````javascript #!/usr/bin/env node var argv = require('yargs').argv; if (argv.s) { process.stdout.write(argv.fr ? 'Le perroquet dit: ' : 'The parrot says: '); } console.log( (argv.fr ? 'couac' : 'squawk') + (argv.p ? '!' : '') ); ```` *** $ ./bool.js -s The parrot says: squawk $ ./bool.js -sp The parrot says: squawk! $ ./bool.js -sp --fr Le perroquet dit: couac! And non-hyphenated options too! Just use `argv._`! ------------------------------------------------- nonopt.js: ````javascript #!/usr/bin/env node var argv = require('yargs').argv; console.log('(%d,%d)', argv.x, argv.y); console.log(argv._); ```` *** $ ./nonopt.js -x 6.82 -y 3.35 rum (6.82,3.35) [ 'rum' ] $ ./nonopt.js "me hearties" -x 0.54 yo -y 1.12 ho (0.54,1.12) [ 'me hearties', 'yo', 'ho' ] Yargs even counts your booleans! ---------------------------------------------------------------------- count.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .count('verbose') .alias('v', 'verbose') .argv; VERBOSE_LEVEL = argv.verbose; function WARN() { VERBOSE_LEVEL >= 0 && console.log.apply(console, arguments); } function INFO() { VERBOSE_LEVEL >= 1 && console.log.apply(console, arguments); } function DEBUG() { VERBOSE_LEVEL >= 2 && console.log.apply(console, arguments); } WARN("Showing only important stuff"); INFO("Showing semi-important stuff too"); DEBUG("Extra chatty mode"); ```` *** $ node count.js Showing only important stuff $ node count.js -v Showing only important stuff Showing semi-important stuff too $ node count.js -vv Showing only important stuff Showing semi-important stuff too Extra chatty mode $ node count.js -v --verbose Showing only important stuff Showing semi-important stuff too Extra chatty mode Tell users how to use yer options and make demands. ------------------------------------------------- area.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .usage('Usage: $0 -w [num] -h [num]') .demand(['w','h']) .argv; console.log("The area is:", argv.w * argv.h); ```` *** $ ./area.js -w 55 -h 11 The area is: 605 $ node ./area.js -w 4.91 -w 2.51 Usage: area.js -w [num] -h [num] Options: -w [required] -h [required] Missing required arguments: h After yer demands have been met, demand more! Ask for non-hyphenated arguments! ----------------------------------------- demand_count.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .demand(2) .argv; console.dir(argv); ```` *** $ ./demand_count.js a Not enough non-option arguments: got 1, need at least 2 $ ./demand_count.js a b { _: [ 'a', 'b' ], '$0': 'demand_count.js' } $ ./demand_count.js a b c { _: [ 'a', 'b', 'c' ], '$0': 'demand_count.js' } EVEN MORE SHIVER ME TIMBERS! ------------------ default_singles.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .default('x', 10) .default('y', 10) .argv ; console.log(argv.x + argv.y); ```` *** $ ./default_singles.js -x 5 15 default_hash.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .default({ x : 10, y : 10 }) .argv ; console.log(argv.x + argv.y); ```` *** $ ./default_hash.js -y 7 17 And if you really want to get all descriptive about it... --------------------------------------------------------- boolean_single.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .boolean('v') .argv ; console.dir(argv.v); console.dir(argv._); ```` *** $ ./boolean_single.js -v "me hearties" yo ho true [ 'me hearties', 'yo', 'ho' ] boolean_double.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .boolean(['x','y','z']) .argv ; console.dir([ argv.x, argv.y, argv.z ]); console.dir(argv._); ```` *** $ ./boolean_double.js -x -z one two three [ true, false, true ] [ 'one', 'two', 'three' ] Yargs is here to help you... --------------------------- Ye can describe parameters fer help messages and set aliases. Yargs figures out how ter format a handy help string automatically. line_count.js: ````javascript #!/usr/bin/env node var argv = require('yargs') .usage('Usage: $0 <command> [options]') .command('count', 'Count the lines in a file') .demand(1) .example('$0 count -f foo.js', 'count the lines in the given file') .demand('f') .alias('f', 'file') .nargs('f', 1) .describe('f', 'Load a file') .help('h') .alias('h', 'help') .epilog('copyright 2015') .argv; var fs = require('fs'); var s = fs.createReadStream(argv.file); var lines = 0; s.on('data', function (buf) { lines += buf.toString().match(/\n/g).length; }); s.on('end', function () { console.log(lines); }); ```` *** $ node line_count.js count Usage: line_count.js <command> [options] Commands: count Count the lines in a file Options: -f, --file Load a file [required] -h, --help Show help [boolean] Examples: line_count.js count -f foo.js count the lines in the given file copyright 2015 Missing required arguments: f $ node line_count.js count --file line_count.js 26 $ node line_count.js count -f line_count.js 26 methods ======= By itself, ````javascript require('yargs').argv ```` will use the `process.argv` array to construct the `argv` object. You can pass in the `process.argv` yourself: ````javascript require('yargs')([ '-x', '1', '-y', '2' ]).argv ```` or use `.parse()` to do the same thing: ````javascript require('yargs').parse([ '-x', '1', '-y', '2' ]) ```` The rest of these methods below come in just before the terminating `.argv`. <a name="alias"></a>.alias(key, alias) ------------------ Set key names as equivalent such that updates to a key will propagate to aliases and vice-versa. Optionally `.alias()` can take an object that maps keys to aliases. Each key of this object should be the canonical version of the option, and each value should be a string or an array of strings. .argv ----- Get the arguments