ssh-keygen -t rsa
file type checking
file="$1"

touch -d '8 June 2020 11:02'

:%s/search_string/replacement_string/g
# make sure filename supplied as command line arg else die
[ $# -eq 0 ] && { echo "Usage: $0 filename"; exit 1; }

# invoke the is_file_dir and pass $file as arg
is_file_dir "$file"
comment

Email verify , development tools

https://www.tutorialspoint.com/online_dev_tools.htm

echo "My message" | mail -s DEV03.APEXTSI.COM jitenpatel@apex-tech.com

#getting IP address
arp -a | grep 14:10:9f:e0:61:f7 | awk  {'print $2'} | sed -e 's/(//g' | sed -e 's/)//g'


diff <(ls -l reqs/) <(ssh dev04.apextsi.com ls -l /var/www/html/saumitra/aerion/all_development/admin/market/reqs/)

iostat -xtc 5 3

grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'

https://superuser.com/questions/573773/how-do-i-configure-sar-to-collect-disk-information-ala-d


https://www.tecmint.com/install-vnstat-and-vnstati-to-monitor-linux-network-traffic/



https://www.geeksforgeeks.org/vnstat-command-in-linux-with-examples/



for i in $( ls * ); do sed -i '1 s/^/This is my first line\n/' $i; done
for i in $( ls * ); do cat $i; done
for i in $( ps -ef | grep rsync | awk {'print $2'} ); do kill -9 $i; done
$ sed '1 s/^/This is my first line\n/' file1 > file2

while read line ; 
do 
    lineCols=( $line ) ;
    echo "${lineCols[0]}"
    echo "${lineCols[1]}"
done < $myFQFileToRead ;

while read whole_line ; 
do
     something with "$whole_line"
done

#if you only want only column 1 in $first, and everything else in $second_and_rest_of_line:
while read  first second_and_rest_of_line
 do
     something with "$first" and "$second_and_rest_of_line"
done

#if you only want col 1 and 2, and don't care about any extra cols:
while read  first  second  nonimportant
do
    something with $first and "$second" #we don't care about $nonimportant's content
done


https://www.willmaster.com/library/web-development/replace-div-content.php
https://stackoverflow.com/questions/21698459/how-to-change-content-without-reloading-the-page
https://stackoverflow.com/questions/14429854/load-a-certain-div-without-refreshing-the-page-in-a-query



<?php

  exec('tail /var/log/apache2/error.log', $error_logs);

  foreach($error_logs as $error_log) {

       echo "<br />".$error_log;
  }

 ?>

Php file content read

http://php.net/manual/en/function.fread.php

https://www.tutorialrepublic.com/php-tutorial/php-file-system.php

https://www.w3resource.com

http://html5doctor.com/element-index/

https://www.tutorialspoint.com/php/php_files.htm

http://www.studentstutorial.com/php/number-to-words.php

https://www.phptpoint.com/html-tags/

https://www.studentstutorial.com/php/send-otp-through-mail.php


Php form submit

https://www.w3schools.com/html/tryit.asp?filename=tryhtml_form_submit


https://superuser.com/questions/156189/how-to-convert-word-doc-to-pdf-in-linux


js for loop
https://www.w3schools.com/jsref/met_doc_getelementsbyname.asp

document.write js example
https://www.youtube.com/watch?v=m1gs57iz3J0

https://www.ateamsystems.com/services-support/pricing/

SELECT sum(TABLE_ROWS) FROM INFORMATION_SCHEMA.TABLES where table_schema = 'aerion';
select sum((data_length + index_length) / 1024 / 1024)as database_size from INFORMATION_SCHEMA.TABLES where table_schema = 'aerion';


https://www.phpclasses.org/package/6709-PHP-Limit-the-speed-of-files-served-for-download.html#information

Execute shell from mysql
\! ls -l

update aerion.dev_est set owner_ref_tab = 'emp';
update aerion.dev_est set est_ref_tab = 'emp';
update aerion.dev_est set owner_ref_id = owner_id;
update aerion.dev_est set est_ref_id = estimater_id;

https://www.ip2location.com/free/plugins

https://www.snel.com/support/how-to-configure-802-1q-vlan-tagging-on-centos-7/

https://www.kernel.org/doc/Documentation/networking/ipvlan.txt