Ambidexterious

Qualcomm Short Term

2023-06-29T09:44:00.002-07:00

113 is the SL.

1st Target by mid July.

Bharti Airtel Analysis

2023-06-23T18:41:00.002-07:00

Entry/Exit and SL for the Bharti Airtel.

Daily/Weekly Time frame looks bullish.

DAILY

Weekly

Basket Swing Trading

2023-06-18T11:39:00.001-07:00

1. Super Trend usages

a. 1 hour buy trend

b. Day hour buy trend

c. Check Weekly Volume UP

d. Market is more than 1Cr

--> STOP LOSS: Day High Break

Example:

WEEKLY

Monthly

Daily

Technical Question May 22

2022-04-30T21:42:00.004-07:00

Technology

Difference between EEPROM and Flash memory.

- Flash memory is a non volatile storage memory which is electrically erasable and

programmable one.

- Flash memory is a special type of EEPROM.

- Flash memory can be erased and programmed in large blocks where as in EEPROM it

is in small blocks.

- Erase cycles are slow in EEPROM, this is advantages for flash memory for speed up

operations.

- Flash memory takes less power compared to the EEPROM.

- EEPROMS are generally used to store configuration information and booting

information.

- Flash memories are used in USB, memory cards etc.

Explain about I2C protocol. Is it possible to have more number of masters in the same

I2C lines.

- I2C "Inter Integrated Circuit" is a low level communication protocol used between low

speed devices.

- It is a two wire interface one line for Clock and other is for data line.

- I2C is simplex communication protoocol.

- I2C follows Master - Slave Communication protocol.

- I²C bus is a multi-master bus, which means more than one device capable of initiating

a data transfer can be connected to it. Master provides theClock to the slave devices.

- In a 8-bit address line first bit is used to indicate start bit with remaining 7-bits it can

able connect 2^7 devices.

- The communication between ?Master and Slave is as follows

1. Master waits until it sees no activity on the I2C bus. The SDA and SCL lines are

both high. The bus is 'free'.

2. The Master MCU issues a start condition, telling that "its mine - I have started

to use the bus". This condition informs all the slave devices to listen on the serial data

line for instructions/data.

3. Provide on the SCL line a clock signal. It will be used by all the ICs as the

reference time at which each bit of data on the SDA line will be correct (valid) and can be

used. The data on the data line must be valid at the time the clock line switches

from 'low' to 'high' voltage.

4. The Master MCU sends the unique binary address of the target device it wants

to access.

5. Master MCU puts a one-bit message (called read/write flag) on the bus telling

whether it wants to SEND or RECEIVE data from the other chip. This read/write flag is an

indication to the slave node whether the access is a read or a write operation.

6. The slave node ICs will then compare the received address with its own

address. The Slave device with the matching address responds back with an

acknowledgement signal. If the address doesn't match, they simply wait until the bus is

released by the stop condition.

7. Once the master MCU receives the acknowledgement signal, it starts

transmitting or receiving and the data communication proceeds between the Master and

the Slave on the data bus. Both the master and slave can receive or transmit data

depending on whether the communication is a read or write. The transmitter sends 8-bits

of data to the receiver, which replies with a 1-bit acknowledgement. And the action of

data transfer continues.

8. When the communication is complete, the master issues a stop condition

indicating that everything is done. This action free ups the bus. The stop signal is just

one bit of information transferred by a special 'wiggling' of the SDA/SCL wires of the bus.

Explain abot SPI protocol. How slave able to know it is write operation or read operation.

- SPI serial peripheral interface is three wire communication protocol in this one line for

Clock, two wires for MISO & MOSI, one optional one for Chip Select(CS).

- It is a Master-Slave communication protocol.

- SPI operates at full duplex (means, signals carrying data can go in both directions

simultaneously).

- SPI can have more number of Master or more number of Slaves. Master initiates the

communication. If more number of Slave are present GPIO pins are used for CS.

- Gives higher throughput than I2C.

1. The communication is initiated by the master all the time. The master

first configures the clock, using a frequency, which is less than or equal to the maximum

frequency that the slave device supports. The master then select the desired slave for

communication by pulling the chip select (SS) line of that particular slave-peripheral

to "low" state.

2. A full duplex data transmission can occur during each clock cycle.

That means the master sends a bit on the MOSI line; the slave reads it from that same

line and the slave sends a bit on the MISO line; the master reads it from that same line.

3. Data transfer is organized by using Shift register with some given

word size such as 8- bits (remember, its not limited to 8-bits), in both master and slave.

They are connected in a ring. While master shifts register value out through MOSI line,

the slave shifts data in to its shift register.

Jammu Plans 22

2022-02-10T07:15:00.001-08:00

Place to visit Jammu: https://traveltriangle.com/blog/best-places-to-visit-in-jammu/

Place to visit Udhampur: https://www.tripadvisor.in/Attractions-g12375023-Activities-Udhampur_District_Jammu_Jammu_and_Kashmir.html

Place to visit Patnitop: https://www.tripadvisor.in/Attractions-g1152719-Activities-Patnitop_Udhampur_District_Jammu_Jammu_and_Kashmir.html

Place to visit Srinagar: https://www.tripadvisor.in/Attractions-g297623-Activities-Srinagar_Srinagar_District_Kashmir_Jammu_and_Kashmir.html

--> See Mughal Gardens:- Visit Pari Mahal Then visit to Chesham Shahi and Shalimar Garden known as 'Garden of love' in the evening enjoy a romantic SHIKARA RIDE on world famous Dal Lake in which you will cover, Floating Gardens, Vegetable Gardens, Golden Lake, Inner markets like Mena Bazar, and Canals etc, also enjoy the scenic view of Zabarwan Mountains, Overnight stay at the Houseboat.

--> Srinagar -Gulmarg (45 kms / approx. 90 Mins drive)

Gondola ride (cable car Included In Package) from Gulmarg to Kongdoori & Marry Shoulder

--> Srinagar - Pahalgam (98KMS / approx. 3½ hour drive)

visit Saffron fields, Avantipur ruins and Anantnag sulphur spring. Pahalgam is the most famous place for Indian Film Industry. Pahalgam is also famous for its alpine treks, nature walk and is also the central point of Amaranth Yatra.

--> Day Excursion to Sonmarg (90 kms / approx. 3 hour drive)

many places you can enjoy the view of paddy fields with rivers flowing on one side.in Sonamarg you can visit Thajwas Glacier which is around 4Kms from Sonamarg a Local Taxi Or Pony Ride has to be hired (on your own Expenses) in the evening return back to Srinagar overnight stay in Hotel at Srinagar.

Sonmarg:https://www.youtube.com/watch?v=_Kb6W4LiKhM

BIKE Rent in Srinagar: 7569374836 ( Driven)

==============Plans===========

1. Jammu stay: 2 days Min

2. Udhampur : 2 day Min

3. Srinagar: 2 Days Min

4. Buffer : 1 Days

5. Srinagar to HYD

Strategy 6: Rising Wedge Pattern

2020-11-15T08:41:00.004-08:00

The rising wedge is a popular reversal pattern that is predictive in nature and can give traders a clue to the direction and distance of the next price move.

Rising wedges appear regularly in the financial markets and traders gravitate towards the pattern because of its simplicity in identification and application

WHAT IS A RISING WEDGE PATTERN?

The forex rising wedge (also known as the ascending wedge) pattern is a powerful consolidation price pattern formed when price is bound between two rising trend lines. It is considered a bearish chart formation which can indicate both reversal and continuation patterns – depending on location and trend bias. Regardless of where the rising wedge appears, traders should always maintain the guideline that this pattern is inherently bearish in nature (see image below).

HOW TO IDENTIFY A RISING WEDGE PATTERN

The rising wedge pattern is interpreted as both a bearish continuation and bearish reversal pattern which gives rise to some confusion in the identification of the pattern. Both scenarios contain a different set of observation dynamics which must be taken into consideration.

Continuation Pattern:

Established downtrend
Rising wedge consolidation formation
Linking higher highs and lower lows using a trend line assembling towards a narrowing point
Confirm divergence between price and volume using volume function - MACD may also be used
Overbought signal can be confirmed by other technical tools like oscillators (RSI)
Look for break below support for short entry

Reversal Pattern:

Established uptrend
Rising wedge consolidation formation
Linking higher highs and lower lows using a trend line assembling towards a narrowing point
Confirm divergence between price and volume using volume function - MACD may also be used
Overbought signal can be confirmed by other technical tools like oscillators
Look for break below support for short entry

HOW TO TRADE THE RISING WEDGE PATTERN

The chart above shows a rising wedge ‘continuation’ pattern after a determined downtrend. The rising wedge is outlined by the blue dashed lines showing diminishing bull strength in the uptrend. Confirmation of the uptrend waning in strength can be seen using the volume tool on the chart which depicts fading volume in concurrence with the ascending price in the market. This is known as divergence, showing that the upward movement is coming to an end.

The entry point (labelled) occurs once the trend support line of the rising wedge has been breached. There are two common methods of entry:

Wait for a candle close below the support trend line before entry
Enter into the short position as soon as the price breaks the support line, regardless of the candle close

The stop level as highlighted on the chart is elected from the high point of the rising wedge located on the resistance trend line. This identification point makes it relatively simple to locate the stop level for novice traders. The limit in this example was taken from the previous swing low giving this trade an extremely positive risk-reward ratio.

Strategy 5: HEAD AND SHOULDERS PATTERN

2020-11-15T07:24:00.001-08:00

key action points when identifying this pattern:

Identify the overall market trend using price action and technical indicators (preceding uptrend)
Isolate the Head and Shoulders chart construction
The distance between the ‘Head’ and ‘Shoulders’ should be as close to equidistant as possible
Delineate the neckline at the low point between both ‘shoulders’ – preferably horizontal but not obligatory

The Head and Shoulders chart pattern is a price reversal pattern that helps traders identify when a reversal may be underway after a trend has exhausted itself. This reversal signals the end of an uptrend. The Head and Shoulders pattern has a distinctive appearance resembling its namesake which includes a distinct ‘left shoulder’, ‘head’, ‘right shoulder’ and ‘neckline’ formation.

WHAT IS THE INVERSE HEAD AND SHOULDERS PATTERN?

The Inverse Head and Shoulders (informally known as the 'Reverse Head and Shoulders pattern) resembles the same structure as the standard foration but reversed. The Inverse Head and Shoulders is observable in a downtrend (see image below) and indicates a reversal of a downtrend as higher lows are created.

There is a general rule of thumb to designate stop and limit levels. Taking the high point off the ‘right shoulder’ will specify the stop level whilst the vertical distance between the neckline and high of the ‘head’ will approximate the limit distance – 1832.8 pips in this case. The risk-reward ratio on this trade is roughly 1:1.2 which is still within the DailyFX recommended risk management parameters.

Machine Learning

2020-10-25T05:53:00.001-07:00

How to start:

1. Analyze the Train Data completely :

Skewness : https://www.kaggle.com/getting-started/110134
Null values
types of data or values

SMOTE: https://imbalanced-learn.readthedocs.io/en/stable/generated/imblearn.over_sampling.SMOTE.html

Where available, you should select among these using the average parameter.

"macro" simply calculates the mean of the binary metrics, giving equal weight to each class. In problems where infrequent classes are nonetheless important, macro-averaging may be a means of highlighting their performance. On the other hand, the assumption that all classes are equally important is often untrue, such that macro-averaging will over-emphasize the typically low performance on an infrequent class.
"weighted" accounts for class imbalance by computing the average of binary metrics in which each class’s score is weighted by its presence in the true data sample.
"micro" gives each sample-class pair an equal contribution to the overall metric (except as a result of sample-weight). Rather than summing the metric per class, this sums the dividends and divisors that make up the per-class metrics to calculate an overall quotient. Micro-averaging may be preferred in multilabel settings, including multiclass classification where a majority class is to be ignored.
"samples" applies only to multilabel problems. It does not calculate a per-class measure, instead calculating the metric over the true and predicted classes for each sample in the evaluation data, and returning their (sample_weight-weighted) average.
Selecting average=None will return an array with the score for each class.

While multiclass data is provided to the metric, like binary targets, as an array of class labels, multilabel data is specified as an indicator matrix, in which cell [i, j] has value 1 if sample i has label j and value 0 otherwise.

How to handle Multicollinearity

: https://www.analyticsvidhya.com/blog/2020/03/what-is-multicollinearity/

To be checked: https://scikit-learn.org/stable/auto_examples/ensemble/plot_adaboost_multiclass.html#sphx-glr-auto-examples-ensemble-plot-adaboost-multiclass-py

https://scikit-learn.org/stable/auto_examples/ensemble/plot_adaboost_regression.html#sphx-glr-auto-examples-ensemble-plot-adaboost-regression-py

Strategy 4: Bullish Flag Pattern

2020-10-19T09:12:00.006-07:00

Bullish Flag Pattern

Strategy 2: V shape

2020-10-18T07:47:00.001-07:00

V shape Strategy

As the name implies, the "V" chart patterns have the letter "V" shape and prices shift their momentum from an aggressive sell-off to aggressive rally in its structure.

The key factors of the pattern identification:

1. Sharp Downtrend
2. Sharp Uptrend
3. V shaped Pattern (usually 1-3 bars reversals)
4. Volume increase in both breakdown and breakout phases
5. Breakout over neckline
6. Pullback to the Neckline
7. Target

Stop loss: The stop loss is placed under the last lowest one

How to Do Option Chain Analysis

2020-10-18T05:23:00.003-07:00

OPTION Chain Analysis

NSE LINK:

Old Link:

https://www1.nseindia.com/live_market/dynaContent/live_watch/option_chain/optionKeys.jsp?symbolCode=-10006&symbol=NIFTY&symbol=NIFTY&instrument=-&date=-&segmentLink=17&symbolCount=2&segmentLink=17

New Link:

Nifty Bank Analysis 18 oct 2020

2020-10-18T04:50:00.003-07:00

NIFTY Bank Analysis

As we can see it is formed V Pattern we can see the retracement of the 5% from the Top.

So We can short it and Target Around 22600 by Oct End.

INTRADAY: strategy 1

2020-10-18T01:05:00.006-07:00

Today will see the intraday simple strategy it is mostly 90% looks good for me, but need to do the RND

2 Min/ 1 Min strategy ( time frame)
BUY Signal

PRICE is Uptrend
20day EMA is UP
200 day EMA is up

Example:

Nifty:

3. SELL Signal:

200 day EMA is Down.
20 day EMA is down
Price is down

Example Nifty

CandleSticks Basic

2020-10-17T09:40:00.001-07:00

Type of Candle stick:

Bullish

Bearish
DOJI: The Doji is an excellent potential reversal signal. It occurs when the open and the close are the same. Usually, the open and the close are found in the middle of the price range.
HAMMER : It is important to recognize this sing as and indication of a potential reversal When it develop in Harmonic area.

HARMONIC PATTERNS

2020-10-16T11:25:00.006-07:00

HARMONIC PATTERNS:

Content from Below Book:

BOOK: The Harmonic Trader

--------------------------------------------------------------------------------------------------------------------------------

Everyone knows that October historically has been a troubling month for the major markets.
particularly evident when several harmonic calculations converge at a specific price area to define critical support or resistance. This area is known as the Potential Reversal Zone.
The Key to utilizing these harmonic measures when analyzing a price chart is to determine the area where the greatest amount of calculated rations congregate.
When three, four or even five numbers come together within a specific area as defined by their respective structure, you must respect the high probability for some type of reversal.

RULES

Bigger the Pattern, the more significant the potential reversal ( Example : Weekly chart)
If a PRZ contains four or five numbers, the area should be considered very harmonic. If the price action reverse from this area, the PRZ could be considered as an important turning point. BUT if the price action doesn't reverse it worked indicate that the predominant trend is quite strong.
To determine valid reversals and to optimize trade executions. These skills require consistent dedication to research past harmonic examples and to analyze current set-ups.
Price Gap in the PRZ occurs most frequently and is the strongest of all the warning signals. A price gap is an extremely significant indicator of an invalid setup and has kept me out of my bad trade

INTRADAY RULES for Stocks

2020-10-10T09:45:00.008-07:00

INTRADAY RULES for Stocks

I have divided the level in three categories L1/L2/L3. it is up to you what you think in Which Level.

What I have felt in my journey on the Trading sessions I have kept it here.

IMPORTANT LINKS:

https://in.tradingview.com/chart/WITCkega/
https://www.tickertape.in/stocks/pvr-PVRL : Used for check the status of any STOCK it will give more details
https://in.investing.com/portfolio/?portfolioID=Y2dhNzZgYz01azsxZzU3NQ%3D%3D
https://www.screener.in/?gclid=CjwKCAjw_NX7BRA1EiwA2dpg0tnuutOo63PAgEdFF4KuaIwXiMWeEaa8oQxujZK2RL_uQr_0ZN2YWhoCkXoQAvD_BwE : Company Analysis
https://www.moneycontrol.com/markets/technicals/ More details on the Market
https://www.moneycontrol.com/mutual-funds/nav/canara-robeco-blue-chip-equity-fund-direct-plan/MCA212 : Check on the which MF and adding the stock or deleting the stock.
Option Chain Analysis: https://www1.nseindia.com/live_market/dynaContent/live_watch/option_chain/optionKeys.jsp?symbolCode=-10006&symbol=NIFTY&symbol=NIFTY&instrument=-&date=-&segmentLink=17&symbolCount=2&segmentLink=17
https://www.subhashtechlive.com/ : For Daily Resistance and supported provided

=========BEGNIEERS ( L1)============

NO BTST ( Buy Today and Sell Tomorrow or vice versa)
NO HYPOTHESIS/ ASSUMPTION
TRADE WITH ONLY 1 lot in OPTIONS
Don't go 1st with the Target after, taking the Entry first set the Stop loss. do the Trailing Stop loss.
Target for the Minimum 500/1000 per day.
Stick on the Trendlines and Strategies

STRATEGY:

2_Min_with EMA

=========INTERMEDIATE (L2)============

=========EXPERTS (L3) ============

2020-10-10T09:23:00.003-07:00

Entry Exit when the W Pattern seen

Above diagram we can see the W pattern Making so Making the Entry when we see the upward Move.

Keeping the Target Minimum of Middle of the W . Later keep the Trailing Stop Loss

2020-09-25T06:57:00.002-07:00

Trading Strategy

1. Step trend line then book profits.

2. Shadow trend line is to go reverse.

IR (Information Retrieval ) 2nd SEM

2019-02-17T06:09:00.002-08:00

QUIZ

1.Proximity operators are less efficient computationally because the index needs to store positional information.

Data structure SS ZG 519 Information

2018-12-10T10:51:00.001-08:00

1st SEM Data Structure SS ZG 519 paper

Text Book(s)

T1	Algorithms Design: Foundations, Analysis and Internet Examples Michael T. Goodrich, Roberto Tamassia, 2006, Wiley (Students Edition)

Reference Book(s) & other resources

R1	Data Structures, Algorithms and Applications in C++, Sartaj Sahni, Second Ed, 2005, Universities Press
R2	Introduction to Algorithms, TH Cormen, CE Leiserson, RL Rivest, C Stein, Third Ed, 2009, PHI

NOTES:

Link for notes
Previous year papers and solutions:

Data Structure SS ZG 519 paper 1

Data Structure SS ZG 519 paper 2

MTECH (WILP) BITS pilani

2018-12-10T10:40:00.004-08:00

Basic Information for the M.Tech (WILP) with BITS Pilani

I have chosen the Software System. First you have apply to the BITS portal (https://wilpadmissions.bits-pilani.ac.in/ )

For More details you can download the Brochure :https://bits-pilani-wilp.ac.in/m-tech/software-systems.php#downloadbrochuremodal

Once you got the username and password after BITS accepted your application.
you can login to the portal and access the information.

Some Basic Points:

Online class, no offline class.
Only you have to give exams offline, that is you have to go to the center and write the exams. Exams will be paper and pen not objectives.
Quiz will be online mode
Assignment you can prepare and submit to the portal.
you can join class and access the pre recorded videos on mobile/Laptop/Tablet etc.
Mobile apps you can download it from (https://play.google.com/store/apps/details?id=com.moodle.moodlemobile&hl=en) App name is moodle.
BITS have concept of comprehensive and Makeup. if suppose you missed the comprehensive Exam you can give the Makeup. But if you missed both then you are FAIL. no other options.

Android Crash analysis tips

2017-04-07T02:43:00.005-07:00

CRASH Analysis

Crash(Analyze linux crash dump data or a live system) and gdb are both interactive tools, where the user by using a command line interface can analyze
the crash in much more details.

Trace 32(Lautherbach) is a hardware debugger used primary on modified phones and breakout boards.

readelf and addr2line are standard linux tools to examine elf files, e.g. read symbolic informatiion or finding the corresponding
source code giving a PC (program counter) value.

BugReport:
1. It is normally stored on the SD-card (/sdcard/BugReport/BugReport-<IMEI>-date&time.gz
2. log file requires 250KB+ free space.
3. "adb bugreport" can be used to generate the bugreport.
4. chkBugReport is a tool that does some parsing and visualization for the bugreports.(https://github.com/sonyxperiadev/ChkBugReport)
4.1. it will generate a PDF and contain following info: errros,vm traces, system and event log, Ftrace, Battery history, CPU freq, SurfaceFlinger.
4.2. It contains all process and thier stack traces at the point of saveing the bugreport.
it also does some simple main thread violation check.
4.3. Also, if there is a deadlock between the thread(circular dependency/waiting), that will be reported as well.
4.4. Event log extracts the log generated by the ActivityManager (am_*) and plots a chart showing the running activities and services
4.5. Crash Info page tries to show all relevent information that can be found in vmcore file(eg. if carash notes information about current process,
crash register is available)

Find the source (line number where crash happen)
addr2line -e bluetooth.default.so 0x8200345a --> btif_config.c:144
using abouve command line tool (addr2line) we can find the corresponding source code line, in this case line 144 in btif_config.c

from the log we will the address 0x8200345a in program counter
NOTE: we need the same execuitable/.so file where the crash happen.

Android log files can view using the following commands:
1. adblog -m (main)
2. adblog -s (system)
3. adblog -e (event)
4. adblog -r (radio)

Debugging segmentation Fault using GDB

2017-04-07T02:42:00.002-07:00

GDB:
It is a general debugger and is the recommended tool to analyze problems in user land.

First we have to compile our source code with below option:

1. gcc -g -O0 test.c
2. gdb a.out
gdb -x gdb_cmd_for_processid : --> Run gdb using dump file

below are the some basic command which we use while debugging:

$(gdb) bt : command for the call stack for selected thread
$(gdb) bt full : commands for the call stack with values of the local variables
$(gdb) info threads : to show the list of threads
$(gdb) info th[reads] [<thread number>]: to show the particular thread
$(gdb) frame[<number>]: show current frame
$(gdb) info lo[cals] : to show local variable in current frame
$(gdb) info ar[gs]: to show parameters to current frame
$(gdb) disas[semble]: disassemble current function or specified function.
$(gdb) wha[tis]<variable> : show type for a variable/function
$(gdb) print <expr> : to print the value of the expression or variable.
$(gdb) help<command> : to get more information on the commmadns use help

Manifest File and repo commands

2017-04-06T02:35:00.001-07:00

Inside of the manifest file

The manifest file can be found in hidden directory under the project root.(.repo/manifests/default.xml)

The directory .repo/manifest is a git repository.
The branches in this git reflect the branhes in the project

<manifest>
.....
...

[below are the list of project, above this line are Manifest head]
<project path="system/bt" name="system/bt"/>
<project path="hardware/libhardware" name="hardware/libhardware"/>

<manifest>

---------Most common Repo commands------
1. repo sync --> Download the latest changes in all repositories.
2. repo start --> Create a new branch
3. repo upload --> Upload one or more change to gerrit

Major issue :

If you forgot to create brnach and do the change and want to commit then it will FAIL.

Solution: once your change is ready, then better you can create the patch for your change and then
create the branch. Once branch is created you can apply your patch.

GIT configuration and basic command

2017-04-06T00:53:00.000-07:00

Git practical

About: GIT is a distributed version control system designed to handle everything from small to very large projects with speed and efficiency.

GERRIT: it is purely web based and relies on GIT for storing the source code.

Configure git and repo (on your local machine)

we will setup git on your local machine. This will include user specific configuration settings for git in the .gitconfig file and Gerrit setup.

Configure name and email in ~/.gitconfig file.

1. Start a terminal/shell. To configure your name and email execute these commands and replace with your values.

$ git config --global user.name <"FirstName Lastname">

$ git config --global user.email <username@xyz.com>

2. Run $ git config --global color.ui auto to configure colorization of git output.

3. Run $ git config --global core.editor nano to configure your standard git editor as nano/vim. Choose an editor that you are comfortable with. Nano is a good default choice.

4. Verify in your .gitconfig file that the right credentials have been set.

$ cat ~/.gitconfig

You should now have a section in your ~/.gitconfig file that looks like this

[user]

name = Firstname Lastname

email = username@xyz.com

[color]

ui = auto

[core]

editor = nano

Configure [url] section in ~/.gitconfig file.

Set the URL

$ git config --global url git://review.source_code.org/

SSH key Generation

In this step you will configure SSH Username and email in Gerrit, create an SSH keypair on your local client machine and add your public key to Gerrit.

1. Start a terminal/shell

2. Type the text below with your email address and press Enter.

$ ssh-keygen -t rsa -C username@xyz.com

3. You will now be requested to enter file in which to save the key: DON’T TYPE ANYTHING. Just press Enter when asked.

4. You will now be requested to enter name and password: DON’T TYPE ANYTHING. Just press Enter when asked.

Enter passphrase (empty for no passphrase):

Enter same passphrase again:

5. Your public/private rsa key pair will be generated and stored in ~/.ssh

6. Go to Gerrit page https://review.source_code.org, Settings – SSH Public Keys

7. In the Profile section add (or verify) your username as <username > and then click “Change Username” button to confirm.

8. Click the Add Key button.

9. Open the file id_rsa.pub with a text editor by typing this in a terminal:

        $ vi ~/.ssh/id_rsa.pub

        Copy everything in that file, and paste it into the SSH Keys tab field in Gerrit. Click on Add.

        Your SSH key and SSH Username are now configured in Gerrit. The last step is to add a preferred email.

10. Go to Gerrit page https://review.source_code.org, Settings – Contact information

11.  Register New Email and add your email, if mail id is correct then skip it.

12. If you registered a new email you will receive a confirmation e-mail from Gerrit. There’s a link in the mail, copy the hyperlink into the browser for verification.

*** we will focus on how to reset your working directory and staging area. This is useful if something gets messed up and you need to start over again.

Figure 1

Unstage particular files from the “Staging area”

Create a new file and stage for commit. Also unstage it from the index.

1. Change active directory to ~/aosp/system/bt

2. Open your favorite editor and type something into it. Save the file as backup.txt

3. View repository status by running git status. Change file reside in “working directory” according to above figure1.

4. Now add your file, git add backup.txt

5. Run git status again. Change file reside in “Staging area” according to above figure 1.

6. You want to unstage the file from the “staging area”.

You can do this by using git reset -- file. Now reset the file,

$ git reset -- backup.txt

Backup.txt file will get removed, if it is newly created, otherwise the changes what we have done, it will get reverted.

Unstage all files from the “Staging area”.

1. Change work directory to ~/aosp/system/bt/. Modify 2 or more files and Run git status, several files and added them to the staging area.

2. Now you want to unstage all files in the “Staging area”, this can be done with git reset. If no file/ files are specified, all files will be unstaged. Run git reset and then check the result by running git status.

How to restore all back to normal.

1. Change work directory to ~/aosp/system/bt/. If you run git status in here, you will find that we have modified several files.

	Working directory	Staging area
Tracked	tracked-working.txt	tracked-added_to_staging.txt
Untracked	untracked-working.txt	untracked-added_to_staging.txt

Figure 2

2. You want to undo your changes and restore everything to your latest commit (HEAD). This can be done with git reset –hard(this will move the tracked file to untracked section of files).

5. Now undo your other changes to restore all remaining files to HEAD,

$ git reset --hard HEAD

5. Run git status and compare with figure 2.

We will not get any change files, we will get only the original files.

git log –Show commit logs

1. Change active directory to ~/aosp/system/bt.

2. Do a git log within the directory to view the history of the repository.

$ git log

3. List all local branches using git branch. The * in front of master indicates that this is the currently checked out branch. You will also find another branch in the list. Now view the history for the branch feature.

$ git log branch_name

4. It is possible to view history for specified files or directories.

$ git log -- file

git diff -Show changes between commits, commit and working tree etc.

1. Change active directory to ~/aosp/system/bt/ if not already set.

2. Choose one of the files. Open it in an editor and make a change to it.

3. Use git diff to show the difference between your working directory and the index.

$ git diff

Now we will learn how to amend a commit with faulty author. We will also upload a new patch set to an existing change in Gerrit.

Amend a commit with a wrong author. In this step we have already created a commit ready for upload.

1. Change active directory to ~/aosp/system/bt

2. Make sure that system_bt is checked out. On this branch we have prepared a commit for you to submit for code review in Gerrit.

3. Using repo upload . you will now upload changes to Gerrit.

When asked to confirm the upload, press y and enter.

If it is success then you will get the full gerrit URL

4. If you want to change the author of gerrit then we can change by below command.

$ git commit –-amend –-author="Firstname Lastname <username@xyz.com>"

When it is time to enter the commit message, you will find that the previous commit message is now prefilled for you. This is because you in fact are rewriting that commit. Just save and exit, there is no need to change the message.

Use git log to check that author of the commit now username@xyz.com

5. Now reattempt the upload command.

6. Please note down the URL that is given by the upload command. Review your change in Gerrit by surfing to the URL.

Upload a new patch set to an existing change in Gerrit.

1. Make sure that you have system_bt branch checked out.

2. Open the file Makefile(or any file where you want to change it) and correct the faulty line.

3. We now want to add this fix into the commit that already contains the original change. Add your file with git add, and then to include the fix in the the previous commit run this:

$ git commit –-amend ( don’t change the CHANGE ID)

4. Verify that your change is complete, run git log and git diff to verify!

5. You now want to upload your amended commit as a new patch set to your change in Gerrit. This is done using the --replace option.

$ repo upload

6. Verify your new patch set in Gerrit.

other git command with one line desciption:

1. git rm test.c --> it will remove the file from the git reprository
2. git commit --> to add the commit message and make the patch
3. git format-patch -1 --> it will create the patch for the last commit .

BRANCHES: A branch is only a pointer to a commit.
4. git checkout localbranch --> swithch between branch, switch to brnach localbranch
5. git branch mylocalbranch --> for creating local brnach
6. git commit --amend --> to apply the changes to git(if cherry pick being used), we can use this when we want to ammend the
change to the already existing gerrit.