doc: add example using FileMagic and update README

README.md

@@ -15,6 +15,60 @@ The projects directly uses the native C implementation of libmagic, transpiled t
 
 NOTE: file system access is required and therefore the module is only useful in node.js environment. There is possibility though to enhance it to provide content identification using buffers and with the magic file preloaded in emscripten virtual filesystem (not implemented for now).
 
+### Using the simple FileMagic API
+
+```typescript
+import * as fs from 'fs';
+import * as path from 'path';
+import { FileMagic, MagicFlags } from '../lib/index';
+
+// Tell FileMagic where to find the magic.mgc file
+FileMagic.magicFile = path.normalize(
+  path.join(__dirname, '..', '..', 'dist', 'magic.mgc')
+);
+
+// We can onlu use MAGIC_PRESERVE_ATIME on operating suystems that support
+// it and that includes OS X for example. It's a good practice as we don't
+// want to change the last access time because we are just checking the file
+// contents type
+if (process.platform === 'darwin' || process.platform === 'linux') {
+  FileMagic.defaulFlags = MagicFlags.MAGIC_PRESERVE_ATIME;
+}
+
+// Get the single instance of FileMagic and work with it
+FileMagic.getInstance()
+  .then((magic: FileMagic) => {
+    // The version is a number with the left most digit being the major
+    // version and the other digits are the minor
+    const version = magic.version();
+    const major = ('' + version).charAt(0);
+    const minor = ('' + version).substr(1);
+    console.log(`Using magic version: ${major}.${minor}`);
+
+    // We can call the detection methods
+    const files = fs.readdirSync('.');
+    console.log(`${files.length} files to check`);
+    files.forEach(file => {
+      console.log(
+        file,
+        ' : ',
+        magic.detect(file, magic.flags | MagicFlags.MAGIC_MIME)
+      );
+      console.log(file, ' : ', magic.detect(file));
+    });
+
+    // When we are done, close
+    FileMagic.close();
+  })
+  .catch((err: Error) => {
+    console.error(err);
+    // when the initialization fails, FileMagic already cleans up, but
+    // there is no harm in getting used to always close when no longer 
+    // needed.
+    FileMagic.close();
+  });
+```
+
 ### Using the raw binding
 
 ```typescript

examples/file-magic-example.ts

@@ -0,0 +1,49 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { FileMagic, MagicFlags } from '../lib/index';
+
+// Tell FileMagic where to find the magic.mgc file
+FileMagic.magicFile = path.normalize(
+  path.join(__dirname, '..', '..', 'dist', 'magic.mgc')
+);
+
+// We can onlu use MAGIC_PRESERVE_ATIME on operating suystems that support
+// it and that includes OS X for example. It's a good practice as we don't
+// want to change the last access time because we are just checking the file
+// contents type
+if (process.platform === 'darwin' || process.platform === 'linux') {
+  FileMagic.defaulFlags = MagicFlags.MAGIC_PRESERVE_ATIME;
+}
+
+// Get the single instance of FileMagic and work with it
+FileMagic.getInstance()
+  .then((magic: FileMagic) => {
+    // The version is a number with the left most digit being the major
+    // version and the other digits are the minor
+    const version = magic.version();
+    const major = ('' + version).charAt(0);
+    const minor = ('' + version).substr(1);
+    console.log(`Using magic version: ${major}.${minor}`);
+
+    // We can call the detection methods
+    const files = fs.readdirSync('.');
+    console.log(`${files.length} files to check`);
+    files.forEach(file => {
+      console.log(
+        file,
+        ' : ',
+        magic.detect(file, magic.flags | MagicFlags.MAGIC_MIME)
+      );
+      console.log(file, ' : ', magic.detect(file));
+    });
+
+    // When we are done, close
+    FileMagic.close();
+  })
+  .catch((err: Error) => {
+    console.error(err);
+    // when the initialization fails, FileMagic already cleans up, but
+    // there is no harm in getting used to always close when no longer 
+    // needed.
+    FileMagic.close();
+  });