Using android adb shell

To excute shell command using your pc, connect device to your system, and give command as "adb devices", to check whether device is connected properly or not.
Now you can excute "adb shell" command to access shell of your device.

All available shell commands for Android phones can be checked using below command:

adb shell ls /system/bin

rm : It's similar to rm command of Unix to remove files and directories.

rmdir : rmdir(rd) command removes an empty directoryon Unix, windows, DOS systems

Some important adb commands for android debugging

adb root       - To get root access on device, this will provide full permission to user
adb remount - Remounts /system partition on the device
adb push      - To push any file, into device file system.

e.g. adb push <local system path>\<filename> <path on device>/<filename>

adb pull:  To pull out file form the device

e.g. adb pull <path on device>/<filename> <local system path>\<filename>

adb shell       - To enter into device's command prompt, and to execute shell command for device.
adb install     - To install any apk file( application file)

 e.g adb install mytest.apk

adb uninstall  - To remove application
adb version   - To know the adb tool version
adb devices   - list of devices connected to adb
adb get-serialno - Prints serial number
adb start-server - Starts ADB server
adb kill-server   - Stops ADB deamon server
adb logcat         - Collects device Log

Structure of IMEI and IMEISV

IMEI is called International Mobile station Equipment Identity.
As the name suggests it recognizes the manufacturer of the mobile equipment. It is a serial number which is allocated by equipment manufacturer, and is used to register to network operator, which stores it in EIR (Equipment Identity Register).

This is the serial which is used when your device gets stolen.
IMEI is of total 14 digits pus a check digit, while IMEISV is of 16 digits., this includes information on origin, model, and manufacturer of device.

Format of IMEI: AA-BBBBBB-CCCCCC-D
IMEISV: AA-BBBBBB-CCCCCC-EE

IMEI has following parts:

Type approval code(TAC): 6 decimal places (AA-BBBB), centrally assigned and tells about model
Final Assembly Code(FAC):2 decimal places (BB), tell about location of device's construction and is manufacturer specific.
Serial Number(SNR): 6 decimal places, assigned by manufacturer.
Spare/Checksum: 1 digit

IMEI = TAC+FAC+SNR+Checksum

In the new format of IMEI, FAC doesn't any more exist, now TAC is made 8 digits long and rest all is same.

IMEISV(IMEI Software version): contains 14 initial digits similar to IMEI but last 2 digits are called as Software Version Number (SVN)

To know your IMEA number on your handset, dial *#06#
Now based on this IMEI you can find out information about your device using below site:
IMEI Number Lookup

Example:
49015420: 
Issuer:BAPT

Brand: Nokia
Model: 3110
Manufacturer: Nokia Mobile
Devie type: Phone

A list of Manufacturers and thier TAC is vailable at below link:
List of TAC

AT Commands

Here are few of very common AT commands listed down for use:
AT: to check weather AT commands are working proper.

Call Control:
ATA: answer the Call.
ATD: Dial a call

AT+CGDCONT? : To know APN profiles on phone
AT+CGDCONT=<cmd>, <n>
                                cmd : 1/0 (Activate/Deactivate)
                                 n: number of profile index

Basic Information of Mobile:
AT+CGMI: Name of manufacturer
AT+CGMM: Model number
AT+CGSN: To get IMEI
AT+CGMR: To get software version

Basic information of Subscriber:
AT+CNUM: To get MSISDN
AT+CIMI: To get IMSI

Current Status Of phone:
AT+CREG? : Query
AT+CBC: Current battery charging query
AT+COPS? : Query for current operation state( like operator)

Security Related:
AT+CLCK: Facility locks opening or locking
AT+CPWD: To change password
AT+CPIN? : To check SIM Status

if you want ot know more in detail about AT command please leave a comment.