init

Author: Uday Hiwarale

.gitignore

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+node_modules

README.md

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-# md5-file-cli
-A CLI to display MD5 Checksum of a file's contents.
+# File Checksum CLI
+A CLI tool to calculate checksum of file's content using **md5** or **sha1** algorithms.
+
+## Installation
+```
+$ npm install -g file-checksum
+```
+
+## Help and Version
+```
+$ file-checksum -v
+1.0.0
+
+$ file-checksum --help
+Calculate checksum of a file.
+
+Usage: file-checksum <filepath> [options]
+
+Options:
+  -v, --version                Print current CLI version.
+  -a, --algorithm <algorithm>  Algorithm to be used for hashing (md5 or sha1) (default: "md5")
+  -h, --help                   output usage information
+```
+
+## Calculate checksum
+Once this package is installed globally, you can use `file-checksum` command.
+```
+$ file-checksum <filepath>
+$ file-checksum <filepath> -a sha1
+$ file-checksum <filepath> --algorithm sha1
+```
+
+#### Example
+```
+$ file-checksum test/file.txt
+
+5e7c683623bdabaeae97f8157e80f85c
+```
+
+> If `-a` or `--algorithm` flag is missing, by default **md5** algorithm is used.
+
+---
+
+To create your own CLI tool using node.js, follow my article on [**Medium**](https://itnext.io/making-cli-app-with-ease-using-commander-js-and-inquirer-js-f3bbd52977ac).

index.js

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+#!/usr/bin/env node
+
+const program = require( 'commander' );
+const _ = require( 'lodash' );
+const chalk = require( 'chalk' );
+
+// import package.json
+const package = require( './package.json' );
+
+// import lib/checksum file
+const checksum = require( './lib/checksum' );
+
+// import valid algorithms
+const { ALGORITHMS } =  require( './lib/constants' );
+
+// intialize CLI interface
+program
+.version( package.version, '-v, --version', 'Print current CLI version.' )
+.description( 'Calculate checksum of a file.' )
+.arguments( '[filepath]' )
+.option( '-a, --algorithm <algorithm>', `Algorithm to be used for hashing (${ _.join( ALGORITHMS, ' or ' ) })`, _.first( ALGORITHMS ) )
+.action( ( filepath, options ) => {
+
+    // extract required options
+    const { algorithm } = options;
+    
+    // check for filepath
+    if( _.isEmpty( filepath ) ) {
+        return console.log( chalk.red( `Provide a file path with the command using command : ${ chalk.bold( 'file-checksum <filepath>' ) }` ) );
+    }
+
+    // check for valid algorithm
+    if( ! _.includes( ALGORITHMS, algorithm ) ) {
+        return console.log( chalk.red( `Provide a valid algorithm : use ${ chalk.bold( _.join( ALGORITHMS, ' or ' ) ) }` ) );
+    }
+
+    // calculate checksum
+    checksum.calculate( { filepath, algorithm } );
+} )
+;
+
+// parse command line argument vector
+program.parse( process.argv );
+
+// pick options from commander
+// console.log( program );

lib/calculate-md5.js

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+const md5 = require( 'md5' );
+
+// export function that returns `md5` hash
+module.exports = ( buffer ) => {
+    return md5( buffer );
+};

lib/calculate-sha1.js

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+const sha1 = require( 'node-sha1' );
+
+// export function that returns `sha1` hash
+module.exports = ( buffer ) => {
+    return sha1( buffer );
+};

lib/checksum.js

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+const fs = require( 'fs-extra' );
+const path = require( 'path' );
+const chalk = require( 'chalk' );
+const _ = require( 'lodash' );
+
+// import valid algorithms
+const { ALGORITHMS } =  require( './constants' );
+
+// create a map of hash calculators based on algorith names
+// HASHERS = { <algorithm>: require(<algorithm-hash-calculator-file>) }
+const HASHERS = _.fromPairs( _.map( ALGORITHMS, ( ALGORITHM ) => {
+    return [ ALGORITHM, require( `./calculate-${ ALGORITHM }` ) ];
+} ) );
+
+// current working directory (where terminal is opened)
+const CWD = process.cwd();
+
+// export a common function to calculate checksum
+exports.calculate = ( { filepath, algorithm } ) => {
+
+    // get absolue file path
+    const file = path.resolve( CWD, filepath );
+
+    // check if file exists
+    if( ! fs.existsSync( file ) ) {
+        return console.log( chalk.red( `File at location ${ chalk.bold( file ) } does not exist.` ) );
+    }
+
+    // get file contents in buffer
+    const fileBuffer = fs.readFileSync( file );
+
+    // calculate hash of the buffer
+    const hash = HASHERS[ algorithm ]( fileBuffer );
+
+    // print hash
+    console.log( chalk.green.bold( hash ) );
+
+};

lib/constants.js

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+// hashing algorithms
+exports.ALGORITHMS = [ 'md5', 'sha1' ];

package-lock.json

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+{
+  "name": "file-checksum",
+  "version": "1.0.0",
+  "description": "A CLI tool to display MD5 or SHA1 checksum of a file's contents.",
+  "main": "index.js",
+  "bin": "index.js",
+  "scripts": {
+    "test": "node test/index.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/thatisuday/file-checksum.git"
+  },
+  "keywords": [
+    "checksum",
+    "cli",
+    "md5",
+    "sha1"
+  ],
+  "author": "Uday Hiwarale <[email protected]>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/thatisuday/file-checksum/issues"
+  },
+  "homepage": "https://github.com/thatisuday/file-checksum#readme",
+  "dependencies": {
+    "chalk": "^2.4.2",
+    "commander": "^3.0.0",
+    "fs-extra": "^8.1.0",
+    "lodash": "^4.17.15",
+    "md5": "^2.2.1",
+    "node-sha1": "^1.0.1"
+  }
+}

package.json

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+"Hello World"