[Android Pro] app_process command in Android

reference to : http://blog.csdn.net/wangkaiblog/article/details/46050587

原本覺得存放在／systen／bin／下的monkey、input、am等adb shell命令都是二進制可執行程，偶爾cat input下，發現不是二進制文件，內容以下：

# Script to start "input" on the device, which has a very rudimentary
# shell.
#
base=/system
export CLASSPATH=$base/framework/input.jar
exec app_process $base/bin com.android.commands.input.Input $*

這段腳本的做用就是經過app_process工具啓動放在／system／farmework／下的input.jar 文件。我查看了下framework文件夾裏面的確有input.jar文件。

What is this app_process

Although not that popular 「app_process」 command is used heavily in Android, for example the well know 「am」 script is using it. Everybody knows how to start an application from adb shell:
am start -n yourpackagename/.activityname
However 「am」 is just a shell script and what stays in the base of the am script is our app_process binary:

root@android:/ # cat /system/bin/am
cat /system/bin/am
# Script to start "am" on the device, which has a very rudimentary
# shell.
base=/system
export CLASSPATH=$base/framework/am.jar
exec app_process $base/bin com.android.commands.am.Am "$@"
root@android:/ #

So app_process is the binary used to start java code. All the apps, instrumentations or installations are tarted using this.

Lets see the official usage output:

root@android:/ # app_process
Usage: app_process [java-options] cmd-dir start-class-name [options]
Not quite complete as usual :)