Android - Start an Android application via a shell script?

Using adb, I believe it is possible:

am [start|instrument]
am start [-a <action>] [-d ] [-t <mime_type>]
[-c <category> [-c <category>] ...]
[-e <extra_key> <extra_value> [-e <extra_key> <extra_value> ...]
[-n <component>] [-D] [<uri>]
am instrument [-e <arg_name> <arg_value>] [-p <prof_file>]
[-w] <component>

for example we have android program with Manifest as under:

<manifest xmlns:android=""
  <application android:icon="@drawable/icon">
   <activity class=".Contact" android:label="@string/app_name">
    <action android:value="android.intent.action.MAIN" />
    <category android:value="android.intent.category.LAUNCHER" />

To run the code issue command like this (in one line):

am start -a android.intent.action.MAIN -n