watch linux command is used to run a command at regular intervals.

The command below is the simplest form of watch:

watch YOUR_COMMAND

For instance:

watch df -h

The command above runs df -h (check disk space) every 2 seconds by default.

In order to change the interval:

watch -n 5 df -h

-n or --interval specify update interval in second. The command will not allow quicker than 0.1 second interval.

In case you want to see the differences in your output command use -d or --differences. It wil highlight
when part of your command output changes. For example in our command if disk space usage changes we will see
the new result highlighted.


SIDE NOTE: -h in df command will show a human readable format of disk space in mega byte.


#linux #sysadmin #watch

minimum interval of 0.1 is hardcoded in the source code of watch command in the link below line 171:

http://procps.cvs.sourceforge.net/viewvc/procps/procps/watch.c?view=markup

Thousand separator using format in python:

your_number = 35200000
 print '{:,}'.format(your_number)

#python #format #thousand_separator

A comprehensive management system for Apache Kafka®

https://www.confluent.io/product/control-center/

#kafka #confluent #monitoring

If you want to run a script, ALWAYS log script output into a file or you will be bitten in the ass and would not have any log data for future reference.

In a regular whay when you try to run a python script you would use:

python my_script.py

Anything that will be printed inside of the script will be printed out into the stdout, so you use the below code to put the script output (stdout) into a file:

python my_script.py >> my_script.log

The above command will put the output into a persisted file that can be referenced in the future.

NOTE: The above scenario is for cases when you don't use a log handler in your script, or when
you are in a hurry and just want to put output in a file. Logging solution is definitely a good s
olution.

Finally if you want to run the script in background use:

python my_script.py >> my_script.log 2>&1

2>&1: 1 is for stdin and 2 is for stderr( if exist code of non-success happens). This command s
ays that send stderr messages into stdout.

#linux #python #script #log

You can open new tabs in vim using tabe command:

:tabe

At the top of the vim you would see [No Name] which refers to the current file
name. Now in order to navigate between tabs you can use the below command when your vim is in command mode:

gt

To go to the previous tab use:

gT

#vim #tab #multi_window #gt #tabe #tips

https://stackoverflow.com/questions/32461229/why-use-redux-over-facebook-flux

#react #reactjs #flux #redux

Is learning a new language hard?

The answer is yes and no. It's a bit like writing. Everybody can learn how to write, and you can too. But what if you wanted ro become a poet? Then writing alone is not enough. You need to learn the rythm 🎼

https://medium.com/@ageitgey/how-to-break-a-captcha-system-in-15-minutes-with-machine-learning-dbebb035a710

#tensorflow #machine_learning #captcha #recaptcha

What are cat and zcat commands and what is their differences?

cat is used to print the content of a file (in stdout or a file, etc). It's main usage is when you want to search something in the whole file like a log file:

sudo cat /var/log/nginx/access.log | grep --color "SOMETHING TO SEARCH"

zcat command on the other is used to get the content of a .gz compressed text file like apache.log.1.gz:

sudo zcat /var/log/apache/apache.log.1.gz | grep --color "SOMETHING TO SEARCH"

NOTE: grep command is used to search in a file. the symbol | (pipeline) is used to send (pipe) first command result into the second command.

#linux #grep #cat #zcat #command

Some useful pip (python package manager) command:

show: used to know specific information about a module installed on your system:

$ pip show requests
 Name: requests
 Version: 2.13.0
 Summary: Python HTTP for Humans.
 Home-page: http://python-requests.org
 Author: Kenneth Reitz
 Author-email: me@kennethreitz.com
 License: Apache 2.0
 Location: /Library/Python/2.7/site-packages
 Requires:

search: used to search a python package on pypi.python.org:

$ pip search "suds"
 suds-aop (0.6.1)                  - Lightweight SOAP client (aop's fork)
 ...
 ...
 ...

NOTE: the above list is truncated.

list: list installed packages.

pip list

NOTE: you can grep on pip list to see if a specific package is installed or check its version:

pip list | grep "requests"

freeze: this command does the the same task as list, but its output can be placed inside of the requirements.txt.

uninstall: remove a package from your system:

pip uninstall requests

#python #pip #list #freeze #show #info #search

The table provides a list of useful aggregation functions available in NumPy

#numpy #aggregation #sum #prod #mean #std #min #max #any #all

Some magic about PyCharm:

Type a.if in a .py file and press tab, the final result would be:

if a:

a.ifn:

if a is None:

a.ifnn:

if a is not None:

app.run().main

if __name__ == '__main__':
     app.run()

These are called postfix completion and helps programmers to not go back and forth when coding. You can see the complete list in PyCharm setting.

#pycharm #trick #postfix #auto_completion #postfix_completion

طراحی سایت با لوگین و قابلیت پرداخت برای فروش و دانلود Object 3D
جهت تماس با کارفرما لطفا با شناسه زیر ارتباط بگیرید:
@amir3dsmax

#job #project

Some useful docker commands:

docker stack ls
List stacks or apps

docker stack deploy -c <composefile> <appname>
Run the specified Compose file

docker service ls
List running services associated with an app

docker service ps <service>
List tasks associated with an app

docker inspect <task or container>
Inspect task or container

docker container ls -q
List container IDs

docker stack rm <appname>
Tear down an application

docker swarm leave --force
Take down a single node swarm from the manager

#docker #cheatsheet #inspect #stack #swarm #service

The CLI uses the Docker REST API to control or interact with the Docker daemon through scripting or direct CLI commands. Many other Docker applications use the underlying API and CLI.

#docker #docker_cli #docker_rest #architecture

To change a password on behalf of a user in Linux, first sign on or "su" to the "root" account. Then type:

passwd user

It will prompt for the password and then prompt to retype the password. The password will be change as soon as you enter retype password.

#linux #passwd #change_password

To make a user as sudoer use usermod as below:

usermod -aG sudo username

If it gives error that sudo group does not exist, use groups to see list of users, it maybe root like below:

usermod -aG root username

#linux #sysadmin #usermod #sudo #sudoer #root

ویندوز بالاخره صاحب ssh می‌شه

https://jadi.net/2017/12/windows-ssh/

یکی از چیزهای بسیار عجیب ویندوز، نداشتن ابزارهای گنو است. این ابزارها که احتمالا روی هم ۱۰۰ مگ هم نیستن بخش بزرگی از قدرت کامند لاین لینوکس رو می‌سازن. یکی از مهمترین این ابزارها ssh برای وصل شدن به سرورهای راه دور بود که نبودنش توی لینوکس و اجبار به استفاده از کلاینت های دهه ۹۰ی مثل پاتی (مشهور به پوتی) یکی از شکنجه هایی است که می شه به هر مدیر سیستم لینوکسی داد.

حالا خوشبختانه ویندوز داره قدم به قدم خودش رو اصلاح می کنه و ظاهرا در ویندوز ۱۰ قراره نه فقط کلاینت که سرور اس اس اچ رو هم داشته باشیم. دقیقا بودن این ابزارها در مک یکی از دلایلی است که مدیر سیستم ها حتی اگر دوست نداشته باشن می تونن با مک کار کنن ولی با ویندوز نه.

اگر این گزینه بتا روی سیستم شما فعال شده، می تونین به Manage Optional Features برین و با زدن Add a feature فهرست رو ببینین و اوپن اس اس اچ کلاینت و سرور و فعال کنین. البته ایده اجرا کردن یک سرویس شبکه ای بتا روی ویندوز شاید خیلی عالی نباشه اما به هرحال شروع خوبیه.

کانال @jadinet

#ebook #book #pdf #mongo #mongodb