kmptrnote

#zsh
declare -f FuncName
#How to show zsh function definition (like bash “type myfunc”)?
The zsh idiom is whence, the -f flag prints function definitions:
zsh$ whence -f foo
foo () {
    echo hello
    }
zsh$
In zsh, type is defined as equivalent to whence -v, so you can continue to use type, but you'll need to use the -f argument:

zsh$ type -f foo
foo () {
        echo hello
}
zsh$
And, finally, in zsh which is defined as equivalent to whence -c - print results in csh-like format, so which foo will yield the same results.

man zshbuiltins for all of this.

Works, but only if no alias of the same name happens to be defined, in which case that is reported (whence -f, type -f, which report the highest-precedence form of the command).
declare -f foo is better because even if the function is hidden by an alias, it will still be shown, whereas 'whence' is liable to show just the alias, OR both the alias and the function.

setopt nocasematch
unsetopt nocasematch
setopt #list set options

#tar -C /opt -xzvf node-v4.2.0-linux-x64.tar.gz

#apache
httpd -V
Server version: Apache/2.4.17 (Fedora)
...
Server MPM:     prefork

#how to check if port is open and unused
netstat -tln | tail -n +3 | awk '{ print $4 }'

#&&
03f && ? ".f1*." ".f2*." ".f3*." ".f4*." ".f5*."

#get video dimension from ffmpeg -i
ffprobe -v error -show_entries stream=width,height -of default=noprint_wrappers=1 headscarf\ old\ women.jpg
width=960
height=640

#trim/clip, strip off audio/video
https://gist.github.com/protrolium/e0dbd4bb0f1a396fcb55
ffmpeg -codecs
ffmpeg -formats
https://trac.ffmpeg.org/wiki/Encode/HighQualityAudio
ffmpeg -i InputFile -c copy -ss 00:00:00 -t <duration> OutPutFile
ffmpeg -i InputFile  -vn -acodec copy -ss 00:00:00 -t <duration> OutPutFile
ffmpeg -i MGTOW\ Reason\ \#13\ -\ Aftershock\ From\ The\ Wedding-A17CBtwEmcE.webm -an -vcodec copy aftershock\ marriage-A17CBtwEmcE.webm
ffmpeg -i How\ to\ lace\ dress\ shoes\ ·\ Carmina\ shoemaker-L3p_jjYKImc.mkv -an -vcodec copy -ss 0:0:7 -t 0:0:39 lace_dress_shoe-L3p_jjYKImc.mkv
ffmpeg -i Building\ a\ yurt\ in\ 1.5\ hours\ \(the\ ultimate\ pop\ up\ tiny\ house\!\)-rMKt6xDn19c.mkv -ss 0:0:0 -an -c:v copy -t 0:4:0 build_yurt_popup_tiny_house.mkv;echo $?; ll build*
ffmpeg -i 21\ дарь\ эхийн\ ачлал.mkv -vn -c:a libmp3lame -aq 0 21\ дарь\ эхийн\ ачлал_aq_0.mp3
ffmpeg -i \'In\ Out\'\ Нэвтрүүлэг\ -\ Эдийн\ засгийн\ ухааны\ доктор\ Холбоос\ овогт\ Т.Баярхүү-xfJYJlSfRWM.webm -ss 0:0:15 -vn -c:a libopus -aq 0 -t 0:46:33 Т.Баярхүү2-xfJYJlSfRWM.opus;echo $?

#speed up av
ffmpeg -i Russian\ numbers\ 2\ 10\ 20\ 30,\ 100,\ 1000-vFlzWw62XQo.mp4 -filter:v "setpts=PTS/1.5" -filter:a "atempo=1.5" rus_num_1000-vFlzWw62XQo_1.5spd.mp4

#clip+speed
ffmpeg -i Russian\ Cursive\ Writing\(connecting\ letters\)-ZP8SDSHIk9g.mp4 -c copy -ss 0:0:40 -t 0:5:0 rus_cursive_connected-ZP8SDSHIk9g.mp4 && avspd rus_cursive_connected-ZP8SDSHIk9g.mp4 && echo '$?':$?

#concatenate
FFMeg Concat: "unsafe file name" error
The demuxer accepts the "-safe" option (obviously an input option, to
be placed before the corresponding input file):
    safe
        If set to 1, reject unsafe file paths.
        [...]
        If set to 0, any file name is accepted.
ffmpeg -f concat -safe 0 -i filelist -c copy "swanlake-part1__No.4_Gmajor_K41_II.Andante.mp3"

https://trac.ffmpeg.org/wiki/Concatenate
ffmpeg -f concat -i filelist -c copy "Подмосковные Вечера(en+rss).mp3"
#content of filelist
file '/tmp/Moscow Night  Helmut Lotti-VbZHzF-Av1I.mp3'
file '/tmp/Russian Red Army Choir - Moscow Nights-aw5L0IdKjps.mp3'

#crop, scale
ffmpeg -i crop_1.jpg -vf crop="250:ih-15:0:15" crop_2.jpg
ffmpeg -i pktr/me_kamer_metrik.jpg -vf scale=800:-1 me2015.jpg

#List Cron Jobs
crontab –l –u username

#Edit Cron Jobs
To use cron for tasks meant to run only for your user profile, add entries to your own user's crontab file. Start the crontab editor from a terminal window:
crontab -e
add line:
07,37 * * * * /usr/bin/tunlrupdate.sh

Commands that normally run with administrative privileges (i.e. they are generally run using sudo) should be added to the root user's crontab (instead of the user's crontab):
sudo crontab -e
add same line:
07,37 * * * * /usr/bin/tunlrupdate.sh

Depending on the commands being run, you may need to expand the root users PATH variable by putting the following line at the top of their crontab file:
PATH=/usr/sbin:/usr/bin:/sbin:/bin

#Remove Cron Jobs
crontab -ir

#rename files in respective directories
#find /mnt/0 -type f -iname 'dwn.wait' -execdir mv {} dwn.todo +

#Perl rename
find /mnt/0 -type f -iname 'dwn.wait' -execdir rename -v 's/\.wait/\.todo/' {} \;
#shell built-in rename
find /mnt/0 ~ -xdev -type f -iname 'dwn*' -execdir rename -v dwn dl '{}' \;
find /mnt/0 ~ -xdev -type f \( -iname 'dl' -o -iname 'dl.todo' \) -execdir rename -v dl dllst '{}' \;

find . -type f -exec chmod 644 {} +
find -type f \( -name '*' -or -name '.*' \) -execdir wc -l {} ';'
find -type f \( -name '*' -or -name '.*' \) -execdir wc -l {} \;
find /mnt/0 ~ -type f \( -iname '*07n*' -o -iname '*0n7*' -o -iname '*0o7*' -o -iname '*07o*' \) -exec ls -alF {} +
find /mnt/0 ~ -xdev -type f -iname 'dwn' -execdir rm {} + && echo '$?':$?
#find output redirection works
find /mnt/0 ~ -xdev -type f -iname '*.py' -exec ls -alF {} + > outfile

http://stackoverflow.com/questions/6844785/how-to-use-regex-with-find-command
find /mnt/0 ~ -xdev -type f -regextype posix-extended -regex '.*node.*(\.(pdf|epub|(ppt|doc|xls)x?)?)?' -print
find /mnt/0 ~ -xdev -type f -regextype posix-egrep -regex '.*node.*(\.(pdf|epub|(ppt|doc|xls)x?)?)?' -print
sudo find /mnt/0 ~ -xdev -regextype posix-extended -iregex '.+\.(opus|aac|m4a|flac|mp3|wav)$'

http://askubuntu.com/questions/419115/make-bluetooth-disabled-by-default
rfkill unblock bluetooth
sudo systemctl disable bluetooth.service

DEVICES_TO_DISABLE_ON_STARTUP="bluetooth"
/etc/default/tlp

#Create Symbolic Links in Linux
sudo ln -s /mnt/0/gthb/xrcs/utv.sh /usr/local/bin/utv

grep -Ril "2>&1" .
grep -HinR "usermod -aG" /mnt/0/gthb/xrcs/
alias grep='grep --color=auto -R -n -H -C 5 -i --exclude-dir={.git,.svn,.hg,.bzr,CVS}'

#sed, vim
sed 's/\x22\|\x27//g'  #' "
sed -i.bak "s/\"\\\\n\"/'\\\\n'/g" *.cpp /* cout << "\n" --> cout << '\n' (see Effective Modern C++ by Scott Meyer) */
%s/\(>\s*[/\w.+~-]\+\)\s\+2>&1/\&\1/gc #pattern not found
g/\(>\s*[/\w.-]\+\)\s\+2>&1/s//\&\1/gc #pattern not found
g/\(>.\+\)\s\+2>&1/s//\&\1/gc	#work

7z x -o/mnt/0/vrk -p".*\!#" vrk.7z  #-o{OutputDirectory} x:eXtract with full paths
7z a -p".*\!#" curr.7z curr

less /proc/sys/dev/cdrom/info
cdrecord -minfo -v

grub2-mkconfig -o /boot/grub2/grub.cfg

utl $(cat list)

➜  DEBS sudo dpkg -R -i .

How to modify invalid /etc/sudoers file?
pkexec visudo
Better create custom sudoers in /etc/sudoers.d instead of modifying /etc/sudoers
pkexec visudo -f /etc/sudoers.d/myOverrides

dd if=kali-linux-2017.1-amd64.iso of=/dev/sdb bs=512k

#Stapler is a pure Python alternative to PDFtk, a tool for manipulating PDF documents from the command line
pdf-stapler del photography_BasicPrinciples.pdf 2-8 photography_BasicPrinciples_DavidCapel_346B_IST.pdf
https://github.com/hellerbarde/stapler
sudo dnf install pdf-stapler
#pdftk polymersummit-es6.pdf cat 15-69 72-end output use-es6-with-polymer,2015.pdf
#pdftk Eloquent\ JavaScript,\ 2nd\ Edition.pdf cat 1 8 13-end output eloquent_JavaScript_2nd_ed.NoStarchPress.pdf

cd /mnt/0
fdupes -Sr js nodejs_screencast java cpp aws c c++graphic eecs-ict php embnix nixcpp nixc3d nixpythn socket 01 fpga wbst swift ms tekvid android game hak how pentst

#access and mount iPhone 6 in Linux
sudo apt install ideviceinstaller python-imobiledevice libimobiledevice-utils libimobiledevice4 libplist2 python-plist ifuse 
sudo vim /etc/fuse.conf
idevicepair pair
ifuse /opt/iPhone/
fusermount -u /opt/iPhone

eog - GNOME image viewer

#turn off globbing(wildcard expansion) temporaly/for current session
➜  0 ? https://www.youtube.com/watch?v=kGosatWQ5ag
zsh: no matches found: https://www.youtube.com/watch?v=kGosatWQ5ag
➜  0 disable -p ?                                 
disable: invalid pattern: c
➜  0 disable -p '?'                               
➜  0 ? https://www.youtube.com/watch?v=kGosatWQ5ag
Search for ID [kGosatWQ5ag] now...
find: ‘/home/r/.dbus’: Permission denied
-rw-rw-r-- 1 r r 43429548 сен 25  2014 /mnt/0/oros(Русский)/Weekly Russian Words with Katya - Computer Words-kGosatWQ5ag.mkv
➜  0 enable ?
enable: no such hash table element: ?
➜  0 enable -p ?
➜  0 ? https://www.youtube.com/watch?v=kGosatWQ5ag
zsh: no matches found: https://www.youtube.com/watch?v=kGosatWQ5ag
➜  0 disable -p "?"                               
➜  0 ? https://www.youtube.com/watch?v=kGosatWQ5ag
Search for ID [kGosatWQ5ag] now...
find: ‘/home/r/.dbus’: Permission denied
-rw-rw-r-- 1 r r 43429548 сен 25  2014 /mnt/0/oros(Русский)/Weekly Russian Words with Katya - Computer Words-kGosatWQ5ag.mkv
#persistent effect
setopt noglob
#bash
set -o noglob

diff ~/.zshrc /mnt/0/gthb/xrcs/.zshrc 
diff ~/.zsh-func /mnt/0/gthb/xrcs/.zsh-func 
diff /mnt/0/gthb/xrcs/Makefile /mnt/0/xrc/Makefile

#Delete lines in text file that containing specific string
ex +g/match/d -cwq file

top -b -o +%MEM | head
ps -eo %mem,%cpu,pid,ppid,cmd --sort=-%mem | head

#chntpw
cd %systemroot%/System32/config
sudo chntpw [-u <username>] SAM

#ftp
lcd(local cd) get put del/rm?

#date
\date +"now is week: %V of %Y"
\date +"now is week: %U of %Y"
gsettings set com.canonical.indicator.datetime time-format 'custom'
gsettings set com.canonical.indicator.datetime custom-time-format '%A %B %d %Y %H:%M:%S %:::z'

#linux commnad line weather
curl wttr.in/hailar
curl wttr.in/st.petersburg

https://fedoraproject.org/wiki/How_to_create_and_use_Live_USB#quickstarts
sudo dd if=/path/to/image.iso of=/dev/sdX bs=8M status=progress oflag=direct

#ACL
drwxr-x---+  3 root root 4096 сен 24 17:56 r/
➜ getfacl r
# file: r
# owner: root
# group: root
user::rwx
user:r:r-x
group::---
mask::r-x
other::---

#set ACL
chown -R root:root /mnt/0/*
chown -R root:root /mnt/0/.*
#find /mnt/0 -type f -execdir chmod 640 {} \;
#find /mnt/0 -type d -execdir chmod 750 {} \;
find /mnt/0 -type d -execdir chmod 750 {} \; -execdir setfacl -m u:r:rwx {} \;
find /mnt/0 -type d -name '.*' -execdir chmod 750 {} \; -execdir setfacl -m u:r:rwx {} \;
find /mnt/0 -type f -name '.*' -execdir chmod 640 {} \; -execdir setfacl -m u:r:rw {} \;
find /mnt/0 -type f -execdir chmod 640 {} \; -execdir setfacl -m u:r:rw {} \;
#effective permissions are formed by ANDing permissions with umask.
➜  xrcs git:(master) ✗ getfacl .
# file: .
# # owner: root
# # group: root
# user::rwx
# user:r:rwx			#effective:r-x
# group::r-x
# mask::r-x
# other::---
#
# ➜  xrcs git:(master) ✗ umask 
# 022

#linux recursive search and replace string in directory
find . -type f -execdir sed -i 's/\/media\/r\/0/\/mnt\/0/g' {} \;

#UNIX / Linux Command To Check Existing Groups and Users
➜  xrcs git:(master) ✗ groups r
r : r
➜  xrcs git:(master) ✗ id r
uid=1000(r) gid=1000(r) groups=1000(r)
➜  xrcs git:(master) ✗ id adm
uid=3(adm) gid=4(adm) groups=4(adm)
➜  xrcs git:(master) ✗ id admin
id: ‘admin’: no such user
➜  xrcs git:(master) ✗ getent group r
r:x:1000:
➜  xrcs git:(master) ✗ getent group adm
adm:x:4:
➜  xrcs git:(master) ✗ getent group admin

#Change the Primary Group of a User: usermod -g
usermod -g adm r

#shell cmd
print - $((524288000/1024/1024))

find /mnt/0 ~ ! -path '/mnt/0/linux/*' ! -path '/mnt/0/linux-insides/*' -type f -iname '*debug*' -exec ls -alF {} +
sudo find / -xdev -path /mnt -prune -o -iname 'algorithm' -exec ls -alF {} + ;echo '$?':$?
sudo find / -xdev -path /mnt -prune -o -iname 'algorithm' -printf '%y %p\n';echo '$?':$?
f /usr/include/c++/7/algorithm
f /usr/include/c++/7/ext/algorithm
f /usr/include/c++/7/experimental/algorithm
f /usr/include/c++/7/parallel/algorithm
d /usr/share/perl5/vendor_perl/Algorithm
f /usr/lib64/clang/4.0.1/include/cuda_wrappers/algorithm
$?:0
sudo find / -xdev -path /mnt -prune -o -iname 'algorithm' -exec grep -HiRn 'stl_algo' {} + ;echo '$?':$?
/usr/include/c++/7/algorithm:61:#include <bits/stl_algobase.h>
/usr/include/c++/7/algorithm:62:#include <bits/stl_algo.h>
$?:0

/usr/include/c++/7/parallel/algorithm:35:#include <parallel/algorithmfwd.h>
/usr/include/c++/7/parallel/algorithm:36:#include <parallel/algobase.h>
/usr/include/c++/7/parallel/algorithm:37:#include <parallel/algo.h>

#shell single quote file name with single quote and space
infile_quoted=$(printf \'%s\' "$(printf %s "$infile" | sed "s/'/'\\\\''/g")")
outfile_quoted=$(printf \'%s\' "$(printf %s "$outfile" | sed "s/'/'\\\\''/g")")
echo '"${infile_quoted}"':"${infile_quoted}"
echo '"${outfile_quoted}"':"${outfile_quoted}"
echo '"$infile_quoted"':"$infile_quoted"
echo '"$outfile_quoted"':"$outfile_quoted"
echo '$infile_quoted':$infile_quoted
echo '$outfile_quoted':$outfile_quoted

#read into var
read start _ < <(du -bcm kali-linux-2016-W41-amd64.iso| tail -1); echo $start

scrub -p dod /dev/sdb
echo '$?':$?
$?:0
#or
scrub -p dod /dev/sdb1...

#Find Out What Version of Linux You Are Running
http://www.tecmint.com/find-linux-kernel-version-distribution-name-version-number/
cat /proc/version
cat /etc/os-release
lsb_release -a

lscpu

#disown, nohup
#Detach a Linux Processes From Controlling Terminal
#to completely detach a process from a controlling terminal, use the command format below, this is more effective for graphical user interface (GUI) applications such as firefox:
firefox </dev/null &>/dev/null &
http://www.tecmint.com/run-linux-command-process-in-background-detach-process/

#list all open ports or currently running ports including TCP and UDP
cat /etc/services | less
netstat -lntu

#youtube
framestep through a paused video using , (comma) and . (dot) to go backwards and forwards 1 frame.

#shell debug
1. #!/bin/bash -xv
2. bash/zsh/ksh -xv shellscript

#tee
pstree | tee -a pstree_tee.out

http://docstore.mik.ua/orelly/unix3/upt/ch37_01.htm
#save the debugging output in file and see it on screen? Use tee to copy the scrfile stdout and stderr; add tee to the pipeline before the pager.
# $ scrfile | tee outfile 2>&1 | less
shellscript | tee output 2>&1 | less

tail -f shellscript.log

#linux lock screen and power off display from command line
https://geek1011.github.io/linux-tip-lock-screen-from-command-line/
https://github.com/geek1011/Scripts.sh/blob/master/LockScreen/LockScreen.sh
xset dpms force off
dbus-send --type=method_call --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.Lock

dbus-send --type=method_call --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.Lock;xset dpms force off;utv0

#Linux Unified Key Setup (LUKS)
#The security issue relies due to a vulnerability (CVE-2016-4484) in the implementation of the Cryptsetup utility used for encrypting hard drives via Linux Unified Key Setup (LUKS), which is the standard implementation of disk encryption on a Linux-based operating system.
#modify the cryptroot file to stop the boot sequence when the number of password attempts has been exhausted.
http://thehackernews.com/2016/11/hacking-linux-system.html
sed -i 's/GRUB_CMDLINE_LINUX_DEFAULT="/GRUB_CMDLINE_LINUX_DEFAULT="panic=5 /' /etc/default/grub grub-install

#UEFI
dd;BIOS UEFI mode;secure boot OFF #Kali 2016.2+
dd;BIOS UEFI mode #Fedora

#change case of entire file
dd if=tst.tst of=tst.ucase conv=ucase
diff tst.tst tst.ucase
dd if=tst.tst of=tst.lcase conv=lcase
diff tst.tst tst.lcase

#rpm
rpm -qa | grep rpmfusion
rpmfusion-free-appstream-data-25-3.fc25.noarch
rpmfusion-free-release-25-2.noarch

rpm -qa | grep vlc

rpm -qa | egrep '(uname)|(vim)|(gdb)|(gcc)|(g++)|(git)|(openssl)|(ssh)|(libreoffice)|(ffmpeg)|(gimp)|(vlc)|(firefox)|(xmllint)|(node)|(youtube-dl)' #grep lot more other app

#?
tar -xvzf wkhtmltopdf-0.10.0_rc2-static-amd64.tar.bz2 -C /opt
tar --bzip2 -xf /path/to/boost_1_63_0.tar.bz2

#.tar.lz
tar --lzip -xvf gmp-6.1.2.tar.lz

#clang
clang++ -std=c++14 your_source.cpp -o your_binary

#sort & uniq
#After running sort on an input stream, you can remove repeated lines with uniq as in the example below.
#To indicate the number of occurrences of a line, use the -c option and ignore differences in case while comparing by including the -i option:
sort txt_file | uniq -i -c

#sjis -> utf8
for i in $(find . -xdev -type f -iname '*.*sh' -o -iname '*.sql' -o -iname '*.csv');do
#iconv -f shift-JIS -t utf-8 < ${i} > ${i%.*}_utf-8.${i##*.}  #${var}? vs "$var"
iconv -f shift-JIS -t utf8 ${i} > ${i%.*}_utf8.${i##*.}  #${var}? vs "$var" #man iconv: utf8,utf-8
echo '$?':$?
done

#useradd
useradd amlkcfr && usermod -aG appGrp amlkcfr

#Find Number of Files in a Directory and Subdirectories
FILES=$(sudo find . -type f -print | wc -l)
echo "There are $FILES in the current working directory."

#firefox simplified/text-only print preview
about:config >> print.use_simplify_page
Alt-f-v

#g++
g++ -std=c++11 -Wall -Wextra -O0 -ggdb3 -S numberpermute.cpp /*output: numberpermute.s*/

#make
linux makefile put rules for different programming languages in one makefile (possible with java and c++ on RHEL7.1, tested on Mar.17,2017)

#systemctl
udisks2.service changed on disk. Run 'systemctl daemon-reload' to reload units.

#seq
seq -s, 2 7 100
seq -s, 100

#df
df -aTh

$alias which
which='(alias; declare -f) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot'

#one-liner(env check): utilize ';' , query multiple aliases at once!
echo $CLASSPATH ; echo $JAVA_HOME
java -version ; javac -version
alias jv8c="$JAVA_HOME/bin/javac -g -Xdiags:verbose -d . -classpath ."
alias jv8="$JAVA_HOME/bin/java -classpath ."
alias g++ gcc gxx jv8c jv8

java -Xmx64m -jar c:\workspace\BPO\FileDivision.jar c:\workspace\BPO\conf.properties c:\workspace\BPO\sl4j.properties

#shutdown after wget exit
wgetf url && s0
wgetf url ; s0
scrblk;wgetf url --limit-rate=100k;s0

ps -eo %mem,%cpu,pid,ppid,cmd --sort=-%mem | head

/*
If a script expects a command-line parameter but is invoked without one, this may cause a null variable assignment, generally an undesirable result. One way to prevent this is to append an extra character to both sides of the assignment statement using the expected positional parameter.

variable1_=$1_  # Rather than variable1=$1
# This will prevent an error, even if positional parameter is absent.

critical_argument01=$variable1_

# The extra character can be stripped off later, like so.
variable1=${variable1_/_/}
# Side effects only if $variable1_ begins with an underscore.
# This uses one of the parameter substitution templates discussed later.
# (Leaving out the replacement pattern results in a deletion.)

#  A more straightforward way of dealing with this is
#+ to simply test whether expected positional parameters have been passed.
if [ -z $1 ]
then
  exit $E_MISSING_POS_PARAM
fi

#  However, as Fabian Kreutz points out,
#+ the above method may have unexpected side-effects.
#  A better method is parameter substitution:
#         ${1:-$DefaultVal}
#  See the "Parameter Substition" section
#+ in the "Variables Revisited" chapter.
*/

c/c++ make generate object file in separate directory

#wildcard autocomplete 
#/etc/profile
set -o GLOB_COMPLETE #err!
set completion-ignore-case on

~/.inputrc:
set show-all-if-ambiguous on
#!/usr/bin/env bash
shopt -s extglob   # and others, such as nullglob dotglob
shopt -s dotglob nullglob
shopt -s failglob
shopt -s globstar

sudo ufw allow 139/tcp
sudo ufw allow 445/tcp
sudo ufw allow 137/udp
sudo ufw allow 138/udp
sudo ufw reject 139/tcp
sudo ufw reject 445/tcp
sudo ufw reject 137/udp
sudo ufw reject 138/udp

ipp://192.168.1.140:631/ipp

#MAC -> IP
nmap -sP 192.168.1.0/24 >/dev/null && arp -an | grep 1b:a9:f1:b4:8f | awk '{print $2}' | sed 's/[()]//g'
nmap -sP 192.168.1.0/24 >/dev/null && arp -an | grep 1b-a9-f1-b4-8f | awk '{print $2}' | sed 's/[()]//g'

shopt extglob

~/.inputrc

chsh -s /bin/zsh
chsh -s /bin/zsh <usr>

firefox-esr -private

http://c.learncodethehardway.org/book/ex20.html

#Systemd
http://www.howtogeek.com/216454/how-to-manage-systemd-services-on-a-linux-system/
systemd --version

systemctl status cups.service
systemctl start cups.service 

gnome-terminal --tab-with-profile=Unnamed --working-directory=/home/x --tab-with-profile=Unnamed --working-directory=/home/x/work

#$/etc/init.d/postgresql start
#[ ok ] Starting postgresql (via systemctl): postgresql.service.

systemctl start postgresql.service

#book
Get a Job, Build a Real Career, and Defy a Bewildering Economy

➜  xrc whereis sqlite
sqlite: /usr/bin/sqlite /usr/share/man/man1/sqlite.1.gz
➜  xrc file /usr/bin/sqlite
/usr/bin/sqlite: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=2a525971bb453b5055027afe95874abf3b94f530, stripped
➜  xrc whereis sqlite3
sqlite3: /usr/bin/sqlite3 /usr/share/man/man1/sqlite3.1.gz
➜  xrc file /usr/bin/sqlite3 
/usr/bin/sqlite3: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=27fb684767059284231748075dd874bed1837485, stripped

FUD (fully undetecable) #backdoor with msfvenom ( part of metasploit framework )
Fear, uncertainty and doubt (often shortened to FUD) is a disinformation strategy used in sales, marketing, public relations, politics and propaganda. FUD is generally a strategy to influence perception by disseminating negative and dubious or false information and a manifestation of the appeal to fear.

#windows
winkey+r: mspaint, calc, excel, msword, snippingtool
GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}

echo %windir%
echo %SystemRoot%/SysWOW64
echo %USERPROFILE%Envs

#excel formula
#always use & instead of concatenate()!
=$A$1&" = "&""""&$A$2&""""&";"

#list all group in linux
cut -d: -f1 /etc/group | sort

#Google Chrome Bookmarks Location
~/.config/google-chrome/Default/Bookmarks

#batch convert .png images to .jpg
bash -c 'for image in *.png; do convert "$image" "${image%.png}.jpg"; echo -n “$image:$?,”; done' #-n: do not output the trailing newline

#vlc
$HOME/.config/vlc/vlcrc
#Save snapshots in the same folder as the video;Save snapshots with timestamp(where is the snapshot in the video): filename+current_playback_time.jpg
Video snapshot directory: /$N_$T
Video snapshot file prefix: EMPTY

#youtube-dl
#download range: download byte ranges;determine which bytes correspond to (slice)begin/start and (slice)end times, most likely by peeking into the first or last bytes of the file;reassemble that sequence to play
https://github.com/rg3/youtube-dl/issues/622

<?xml version="1.0" encoding="UTF-8"?>

#clamav
awk -F: '/^[^#]/ { print $1 }' /etc/freshclam.conf | uniq
--exclude-dir=^/sys  --exclude-dir=^/dev --exclude-dir=^/proc
sudo freshclam;sudo clamscan --exclude-dir="^/sys" -i --bell -r /;echo '$?':$?
{ echo "braced logging start."; sudo freshclam; sudo clamscan --exclude-dir='^/sys' -i --bell -r / ; echo "braced logging end."; } &> ~/.cache/clam.log
#braced group logging
#shell group output redirection
{echo $(date) ; /mnt/0/gthb/xrcs/py/sendmail.py /mnt/0/workspace/mail.txt ; echo $(date)} &>> /mnt/0/workspace/test.log && s0
(echo $(date) ; /mnt/0/gthb/xrcs/py/sendmail.py /mnt/0/workspace/mail.txt ; echo $(date)) &>> /mnt/0/workspace/test.log && s0  #execute in subshell

{echo $(date) ; /mnt/0/gthb/xrcs/py/sendmail.py /mnt/0/workspace/mail.txt ; echo $(date)} &>> /mnt/0/workspace/test.log ; s0
(echo $(date) ; /mnt/0/gthb/xrcs/py/sendmail.py /mnt/0/workspace/mail.txt ; echo $(date)) &>> /mnt/0/workspace/test.log ; s0  #execute in subshell

&>> |

# '&>' litter log files with tons of progress string(CTRL-M (^M))! Log only errors instead!
# keep track of wget's input file dir and CD to there if execute other commands and scripts first!
(echo $(date);wget -i dllst;utv;echo $(date);s0) 2>> ~/dl.log &  # shutdown didn't perform successfully when put in background!
(echo $(date);wget -i dllst;utv;echo $(date)) 2>> ~/dl.log ; s0 &

#docker
Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://cloud.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/engine/userguide/

groupadd docker
systemctl restart docker
ll /var/run/docker.sock 
srw-rw----. 1 root docker 0 Jun 25 21:21 /var/run/docker.sock
usermod -aG docker (user)
su - (user) #or log out and log back in again

#record voice from builtin Mic or speaker
pacmd list-sources|awk '/index:/ {print $0}; /name:/ {print $0}; /device\.description/ {print $0}'
ffmpeg -f pulse -i alsa_input.pci-0000_00_1b.0.analog-stereo -c:a libmp3lame Native-Mandarin-Voice-Sample.mp3

#python
#ll ~/.local/lib/
#ll ~/.local/bin/
#set one virtualenv per user:group and give proper system permissions to the folder containing python package? installed with pip install --user <EOL>
https://stackoverflow.com/questions/33412974/how-to-uninstall-a-package-installed-with-pip-install-user
pip install --user -U pip setuptools
https://docs.python.org/3/howto/pyporting.html
http://python-future.org/automatic_conversion.html

#futurize
pip install coverage future pylint caniusepython3 tox six configparser --user
futurize --stage1 -f idioms -w *.py
futurize --stage2 -w *.py
#Note that with recursive globbing in bash or zsh, you can apply stage 1 to all Python source files recursively with:
futurize --stage1 -f idioms -w **/*.py
futurize --stage2 -w **/*.py
###
RefactoringTool: There were 4 errors:
RefactoringTool: Can't parse download/tor-browser_en-US/Browser/TorBrowser/Tor/PluggableTransports/twisted/web/test/test_newclient.py: ParseError: bad input: type=22, value=u'=', context=(u' ', (1641, 17))
RefactoringTool: Can't parse pro-python-best-practices/maze_run-master/part1_debugging/event_loop.py: ParseError: bad input: type=1, value=u'print', context=('', (23, 15))
RefactoringTool: Can't parse pro-python-best-practices/maze_run-master/part1_debugging/to_debug/chapter02_load_tiles.py: ParseError: bad input: type=1, value=u'pygame', context=(u' ', (8, 6))
RefactoringTool: Can't parse pro-python-best-practices/maze_run-master/part1_debugging/to_debug/chapter04_event_loop.py: ParseError: bad input: type=1, value=u'print', context=('', (26, 15))
###

#pasteurize
pasteurize -w **/*.py

pip install --user beautifulsoup selenium chromedriver
##python excel
pip install --user openpyxl pillow
pip install --user kitchen
##html xml
pip install --user lxml requests

python -m site

#python interpreter
http://docs.python-guide.org/en/latest/dev/virtualenvs/#lower-level-virtualenv
export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3

1. pip install --user pipenv
cd myproject
pipenv install requests
pipenv run python main.py
2. Lower level: virtualenv
virtualenv -p /usr/bin/python3 py-prj_vrtenv

http://docs.python-guide.org/en/latest/writing/style/#general-concepts
pip install --user pycodestyle autopep8
pycodestyle optparse.py
autopep8 --in-place optparse.py

autopep8 --in-place --aggressive --aggressive <filename>

#fedora Reinstalling packages with missing/corrupt files
https://unix.stackexchange.com/questions/216697/reinstalling-packages-with-missing-corrupt-files?rq=1
rpm -qf $(rpm -Va 2>&1 | grep -vE '^$|prelink:' | sed 's|.* /|/|') | sort -u

#ll
ll **/*py

#systemd unit file
systemctl daemon-reload;echo $?

sudo systemctl status sysupdate.service
sudo journalctl -o verbose -u sysupdate.service
journalctl -xe

https://superuser.com/questions/476379/how-do-i-setup-a-systemd-service-to-be-started-by-a-non-root-user-as-a-user-daem
Systemd normally does not allow ordinary users to start system services. While it does support giving access via polkit, that part is still somewhat lacking, and you cannot yet allow only one specific service.
Since rtorrent is not actually a system service, and because you want every user to have their own instance of rtorrent, experiment with systemd's "user" mode.
When you log in, the system will start a user@<uid>.service system unit for you, which will launch a separate "--user" instance of systemd. The new user-systemd will read unit files (starting with default.target) from ~/.config/systemd/user/, /etc/systemd/user/ and /usr/lib/systemd/user/.

https://www.brendanlong.com/systemd-user-services-are-amazing.html
Auto-start and lingering
To enable autostart, I just had to run:
systemctl --user enable moin # or ghost or whatever
Then:
loginctl enable-linger moin # this will need authentication from a sudoer

#systemd user timer and service in ~/.config/systemd/user
systemctl --user daemon-reload && systemctl --user enable sysupdate.timer
systemctl --user list-timers -all
journalctl -o verbose -u sysupdate.service
journalctl -xe

#todo: NOT work
#1.sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the 'nosuid' option set or an NFS file system without root privileges?
#2.systemd service: Failed to determine supplementary groups: Operation not permitted
#inside sysupdate.service
#User=nobody
#User=r
#Group=adm

#system startup time
last reboot
who -b

http://www.diveintopython.net/power_of_introspection/filtering_lists.html
Python list filtering syntax:
[mapping-expression for element in source-list if filter-expression]
methodList = [method for method in dir(object) if callable(getattr(object, method))]

#Python Flatten list of lists
#Python convert nested list into one-dimensional list
https://stackoverflow.com/questions/17485747/how-to-convert-a-nested-list-into-a-one-dimensional-list-in-python
The way to do nested list comprehensions is to put the for statements in the same order as they would go in regular nested for statements.
[... for inner_list in outer_list for item in inner_list]
flattened = [val for sublist in list_of_lists for val in sublist]

#git push multiple repos under a directory recursively from command line
for repo in xrcs note;do cd /mnt/0/gthb/$repo && ggpush;done

#check installed Linux Kernels
ls /boot/ | grep vmlinuz
#On RHEL / CentOS / Scientific Linux / Fedora:
sudo rpm -qa kernel
#On Debian / Ubuntu / Linux Mint:
dpkg --list | grep linux-image

rpm -qf $(rpm -Va 2>&1 | grep -vE '^$|prelink:' | sed 's|.* /|/|') | sort -u

#work
sudo find /mnt/0 ~ -xdev -user root -group root -execdir sudo chown -R r:adm {} \;
#NOT work
sudo find /mnt/0 ~ -xdev -user root -o -group root -execdir sudo chown -R r:adm {} \;
#validate with
sudo find /mnt/0 ~ -xdev -user root -group root
sudo find /mnt/0 ~ -xdev -user root -o -group root

#gawk
#output only distinct lines
gawk '!x[toupper($0)]++ {printf "%s ", $0} END {print ""}' dllst
cmd="\? $(gawk -v singlqt="'" '!seen[toupper($0)]++ {printf "%s%s%s ", singlqt, $0, singlqt} END {print ""}' $file)"

#Remove duplicate lines while keeping the order of the lines
https://en.wikipedia.org/wiki/Schwartzian_transform
https://unix.stackexchange.com/questions/194780/remove-duplicate-lines-while-keeping-the-order-of-the-lines
cat -n infile.txt | sort -k2 -k1n | uniq -f1 | sort -nk1,1 | cut -f2- > ._tmp_ && command mv -f ._tmp_ infile.txt

#shell Internal Variables: $$ $!
The $$ variable is the PID (Process IDentifier) of the currently running shell. This can be useful for creating temporary files, such as /tmp/my-script.$$ which is useful if many instances of the script could be run at the same time, and they all need their own temporary files.
The $! variable is the PID of the last run background process. This is useful to keep track of the process as it gets on with its job.

ll (*|.)vim*
-rw-r--r--. 1 r adm 2766 Oct 25 06:24 vimrc_etc
-rw-r-----+ 1 r r   7562 Oct 15 09:50 vim-rfrnc
-rw-r-----+ 1 r r   2785 Sep 10 21:55 .vimrc
ll {.,*}vim*
-rw-r--r--. 1 r adm 2766 Oct 25 06:24 vimrc_etc
-rw-r-----+ 1 r r   7562 Oct 15 09:50 vim-rfrnc
-rw-r-----+ 1 r r   2785 Sep 10 21:55 .vimrc

#algorithm-mnemonics.vim
https://github.com/dawikur/algorithm-mnemonics.vim
g:algorithm_mnemonics_const_return="Left"

#chatbot
http://itchat.readthedocs.io/zh/latest/
pip install --user --upgrade itchat

tr -t '[:upper:]' '[:lower:]' <<< $tst_var

cd ~otherUsrName

ctrl-\
coredump analysis
program record replay toolkit
pinplay Dr debug

time {cmd1 ; cmd2 ...}

#macOS
sw_vers
hostinfo
ls $(dirname $(whereis cat))
basename
PPID: ps -jp PID
history

https://stackoverflow.com/questions/864316/how-to-pipe-list-of-files-returned-by-find-command-to-cat-to-view-all-the-files
find ... -print0 | xargs -0 cat -n

#for each (for-each) in zsh
http://improve-future.com/en/for-each-in-bash-sh-and-zsh.html
local varZip=($(ls *Code.zip))
echo $varZip
for varZ in $varZip;do unzip -d /mnt/0/kod_coderprog $varZ;echo '$?':$?;done

#Linux Unix: Find Files Modified On Specific Date
https://www.cyberciti.biz/faq/unix-linux-list-all-files-modified-on-given-date/
find . -type f -iname '*.rar' -newerct 2017/11/1 ! -newerct 2017/12/25;echo $?
{find . -type f -iname '*.rar' -newerct '2017/12/01' ! -newerct '2017/12/20';echo $?} > 01.txt
{find . -type f -iname '*.rar' -newerct '2017/12/1' ! -newerct '2017/12/20';echo $?} > 1.txt

#mv/cp create destination directory if not exist?
https://stackoverflow.com/questions/547719/is-there-a-way-to-make-mv-create-the-directory-to-be-moved-to-if-it-doesnt-exis
mkdir -p angular-best-practice && mv angular-best-practices.part*rar $_ && cd $_ ; echo '$?':$?
mkdir /mnt/0/essential-git && mv essential-git*rar $_ && cd $_ && ll

DNS settings Linux
r:/etc/resolv.conf
/var/run/NetworkManager/resolv.conf
0. browser: Firefox about:config media.peerconnection.enabled:false, restart Firefox.
1. Open DNS
w:/etc/dhcp/dhclient.conf
exc:service network-manager restart
r:/etc/resolv.conf
2. OpenVPN: vpnbook.com/freevpn
3. DNS leak test: dnsleaktest.com

*nix shell:
<< : heredoc>
<<< : here string

tr -d '\\' <<< '[https://www.youtube.com/watch\?v\=QSPaL4aVjRo]'
[https://www.youtube.com/watch?v=QSPaL4aVjRo]
sed 's/\\//g' <<< '[https://www.youtube.com/watch\?v\=QSPaL4aVjRo]'
[https://www.youtube.com/watch?v=QSPaL4aVjRo]
sed 's/\\//g' <<< [https://www.youtube.com/watch\?v\=QSPaL4aVjRo]
[https://www.youtube.com/watch?v=QSPaL4aVjRo]
tr -d '\\' <<< [https://www.youtube.com/watch\?v\=QSPaL4aVjRo]
[https://www.youtube.com/watch?v=QSPaL4aVjRo]

declare -f delBkslsh

github https -> ssh
ll ktnwr/.git/config; less ktnwr/.git/config
➜  ktnwr git:(master) git remote set-url origin git@github.com:rrrgh/ktnwr.git

SSH
ssh-keygen -o -a 4096 -t ed25519

change email/label: ssh-keygen -c -C 'email@gitconifg' -f <prvt-key-file>

Add SSH key to the ssh-agent
1. eval "$(ssh-agent -s)"
2. Add your SSH key to the ssh-agent. If you are using an existing SSH key rather than generating a new SSH key, you'll need to replace id_rsa in the command with the name of your existing private key file. Enter this command $ ssh-add -K <prvt-key-file>

ssh-add -l
ssh-add -L

https://superuser.com/questions/380432/git-permission-denied-public-key-error
Set SSH configuration file (~/.ssh/config) so SSH knows which key to be used for which server.
Host github.com
  HostName github.com
  User git
  IdentityFile ~/.ssh/<prvt-key-file>

Host github-client
  HostName github.com
  User git
  IdentityFile /Users/XXXUser/.ssh/id_rsa_XXXSECONDUSER

https://superuser.com/questions/421074/ssh-the-authenticity-of-host-host-cant-be-established
➜ ssh-keyscan -t RSA github.com                                          
# github.com:22 SSH-2.0-libssh_0.7.0
github.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==
➜ rtvl 
$?:0
➜ ssh-keyscan -t RSA github.com | ssh-keygen -lv -f -
# github.com:22 SSH-2.0-libssh_0.7.0
2048 SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8 github.com (RSA)
+---[RSA 2048]----+
| =+o...+=o..     |
|o++... *o .      |
|*.o.  *o.        |
|oo.  ..o.= .     |
|.+o. .. S =      |
|*=+ .  o = .     |
|OE .  . o        |
| o     .         |
|                 |
+----[SHA256]-----+

https://stackoverflow.com/questions/2643502/git-permission-denied-publickey
Extensive troubleshooting and even automated fixing can be done with:
ssh -vT git@github.com
Source: http://help.github.com/ssh-issues/