We all know that Android operating system which is widely popular in mobile devices is actually based on Linux. As such it has many features that are present in Linux too. But other features that are not directly accessible, can be used through some third party apps. For example, Linux has a terminal window which is akin to the command prompt window in Microsoft Windows and you can access terminal interface in Android through a free app called Android Terminal Emulator. This way you can issue useful commands like netstat, ping, etc., from even in your Android smartphone.
The Android Terminal Emulator is a simple app that gives you terminal like access to the basic Linux commands in Android. It does not require root access, but if your smartphone is rooted then it can be used to carry out some of the powerful commands.
Using the Terminal Emulator is very simple, just launch this app and it will show you a familiar terminal window that you may have seen previously in Linux computers. You can type in the commands in this window just like you would do in any Linux computer because the syntax and commands are same. But this does not support all the Linux commands and you may often get “access denied” error if your phone is not rooted. You can open many terminal windows by clicking on the small + icon in the Terminal Emulator window.
One of the problems that you may come across the missing Ctrl, Alt, Shift keys in Android soft keyboard. But Terminal Emulator comes around this problem by providing you with simple alternatives. For example, you can press the Volume Down button for Ctrl key. This way you can use Volume Down + C in place of Ctrl+C to cancel a running command.
In the preferences of Terminal Emulator, you can change its look, change font size, change the terminal color, enable UTF fonts (for non-English characters), choose the alternatives for the Ctrl, Alt or Fn keys, choose shell command (usually sh), close the terminal window on exiting the app and more.
Conclusion: Terminal Emulator app for Android brings a simple terminal interface in Android for advanced users. Although it does not support all the Linux commands, it can be used for basic file operations, changing system settings and testing network to name a few.
You can get Android Terminal Emulator app from https://play.google.com/store/apps/details?id=jackpal.androidterm.