gdb print wchar_t *

wchar.gdb

define wchar_print 

        echo "

        set $i = 0
        while (1 == 1)
            set $c = (char)(($arg0)[$i++])
            if ($c == '\0')
                loop_break
            end
            printf "%c", $c
        end

        echo "\n
end

$ gdb -x wchar.gdb  ./myprogram
> wchar_print  mywidevar

or with modern gdb

> set target-wide-charset UTF-16
> p (wchar_t*) mywidevar

Source: https://www.generacodice.com/en/articolo/370005/How-can-I-display-Unicode-strings-while-debugging-on-linux

(Debug) GDB with full colored dashboard

$ pip install pygments

$ wget -P ~ https://git.io/.gdbinit

If gdb version prior to 7.7 and python prior to 2.7 execute this

$ mkdir -p ~/.gdbinit.d/
$ wget 'https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob_plain;f=gdb/python/lib/gdb/FrameDecorator.py' -O ~/.gdbinit.d/FrameDecorator.py
$ sed -i '1s/^/python gdb.COMPLETE_EXPRESSION = gdb.COMPLETE_SYMBOL\n/' .gdbinit
$ sed -i "s/gdb_breakpoint.temporary/None/g" .gdbinit

$ cat >>~/.gdbinit <<EOF
python

import imp
gdb.FrameDecorator = imp.new_module('FrameDecorator')
gdb.FrameDecorator.FrameDecorator = FrameDecorator
end
EOF

You can also send module to be shown on different terminals

start gdb 

$ gdb my_program

in another terminal

$ tty
> /dev/pts/3

in gdb to move Registers to this other terminal 

> dashboard breakpoints -output /dev/pts/3
> dashboard variables -output /dev/pts/3
> dashboard -layout variables stack source breakpoints

to Get help 

>>> help dashboard

Increment version in manifest.json file

$ cat manifest.json | awk -F'["]' -v OFS='"' '/"version":/ { split($4,a,"."); $4=a[1]"."a[2]"."a[3]+1 };1' > _temp_version_ && mv _temp_version_ manifest.json

manifest.json

{
 "version":1.2.3,
...
}

---->

{
 "version":1.2.4,
...
}

TMUX

.tmux.conf

source /usr/share/powerline/bindings/tmux/powerline.conf
set -g mouse on
set -g history-limit 30000

For the mouse work properly using Vim inside Tmux

In your .vimrc add:

set ttymouse=xterm2
set mouse=a

Atalhos TMUX

set -g status off

Type in all panes at same time
ctrl + b   : setw synchronize-panes on

ctrl + b z   maximize current pane

ctr + b t    show a clock, it can be used to ignore typing when in syncronize-panes on

Ctrl+b " — split pane horizontally.
Ctrl+b % — split pane vertically.
Ctrl+b arrow key — switch pane.
Hold Ctrl+b, don’t release it and hold one of the arrow keys — resize pane.
Ctrl+b c — (c)reate a new window.
Ctrl+b n — move to the (n)ext window.
Ctrl+b p — move to the (p)revious window.
Other thing worth knowing is that scrolling is enabled by
Ctr+b  Alt (arrow)  - resize
          Repeat Alt(arrow) - resize more times
Ctr+b Esc (arrow)  - resize
          Repeat Alt(arrow) - resize more times
Ctr+b Option (arrow)  - resize
          Repeat Option(arrow) - resize more times

C-b [    Start scroll mode, so press Arrow up or Page up

q   Exit scroll mode

C-b x          kill the current pane

C-b q          display pane numbers for a short while

C-b {          move the current pane to the previous position
C-b }          move the current pane to the next position
C-b C-o        rotate window ‘up’ (i.e. move all panes)
C-b M-o        rotate window ‘down’
C-b !          move the current pane into a new separate
               window (‘break pane’)
C-b :move-pane -t :3.2
               split window 3's pane 2 and move the current pane there


C-b c          create a new window
Switch between windows:
C-b 1 ...      switch to window 1, ..., 9, 0
C-b 9
C-b 0
C-b p          previous window
C-b n          next window
C-b l          ‘last’ (previously used) window
C-b w          choose window from a list

Disable bell in Vim, Bash

Disable bell in bash autocompletion


/etc/inputrc

 set bell-style none


 Disable bell when pressing ESC in Vim

 ~/.vimrc

set visualbell

curl multiple line request to remote host using HEREDOC and SED

$ curl -d @<(sed 's/##NOME##/'"${1}"'/' << SED_FILE
{
"nome": ##NOME##,
}
SED_FILE
) http://anywebservice.com/name/${1}

SSH Proxy SOCKS - Raspbian / Chromium

alias proxy.on='ssh -D 1337 -q -C -N myuser@mysshserver';
alias chromium.proxy='chromium-browser --proxy-server="socks5://localhost:1337" --host-resolver-rules="MAP * ~NOTFOUND , EXCLUDE localhost"';

Call Oauth Token server and decode JWT (Json Web Token) from command line

function jwt-d() {
     sed 's/\./\n/g' <<< $(cut -d. -f1,2 <<< $1) | base64 --decode | jq
}

decode_base64_url() {
    local len=$((${#1} % 4))
    local result="$1"
    if [ $len -eq 2 ]; then
         result="$1"'=='
    elif [ $len -eq 3 ];
         then result="$1"'='
fi
#echo "$result" | tr '_-' '/+' | openssl enc -d -base64
echo "$result" | tr '_-' '/+' | base64 -d
}

decode_jwt(){

    IFS=. read -r jwt_header jwt_body jwt_trail<<<$(echo -n $1)
    echo -e "HEADER:"
    decode_base64_url ${jwt_header} | jq .
    echo -e "\nBODY:"
    decode_base64_url ${jwt_body} | jq --arg TZ $(date +"%Z") 'if .exp then (.expStr = (.exp + 3600*($TZ|tonumber) |gmtime|strftime("%d %B %Y - %H:%M:%S"))) | del (.exp) else . end | if .ia
t then (.iatStr = (.iat + 3600*($TZ|tonumber) |gmtime|strftime("%d %B %Y - %H:%M:%S"))) | del(.iat) else . end'

    echo -e "TRAIL: \n\n${jwt_trail}"
}

alias jwtd="decode_jwt"

sts_token() {
    local tk=$(curl -k -X POST 'https://geratoken.com.br/api/token' --header 'Content-Type: application/x-www-form-urlencoded' --header 'x-empresa-apikey: XXXXXXXX' --header 'x-empresa-correlationID: 123' --header 'x-empresa-flowID: 456' --data-urlencode 'client_id=XXXXXXX' --data-urlencode 'grant_type=client_credentials'
--data-urlencode 'client_secret=XXXXXXX' --cert ~/certificados/mycert.crt --key ~/certificados/mycerkey.key | jq -r .access_token)
    echo "TOKEN: " ${tk}
    jwtd ${tk}
}

Make your Linux Terminal and VIM statusline more visually beautiful and eye candy with Powerline

sudo apt-get install powerline python3-powerline


.bashrc
powerline-daemon -q POWERLINE_BASH_CONTINUATION=1 POWERLINE_BASH_SELECT=1 . /usr/share/powerline/bindings/bash/powerline.sh

.vimrc
python3 from powerline.vim import setup as powerline_setup 

python3 powerline_setup() 

python3 del powerline_setup 

set laststatus=2 

set t_Co=256

.tmux.conf

source /usr/share/powerline/bindings/tmux/powerline.conf

For Windows Git-Bash or WSL
https://github.com/diesire/git_bash_windows_powerline
https://devpro.media/install-powerline-windows/#configure-vim
https://www.hanselman.com/blog/HowToMakeAPrettyPromptInWindowsTerminalWithPowerlineNerdFontsCascadiaCodeWSLAndOhmyposh.aspx
https://github.com/microsoft/cascadia-code/releases?WT.mc_id=-blog-scottha

Record and Replay Mouse and Keyboard events for User interface test automation

Record 999000 events of mouse and keyboard

$ cnee --record --events-to-record 999000 --mouse --keyboard -o /tmp/xnee.xns


Replay


$ cnee --replay -f /tmp/xnee.xns -v -e /tmp/xnee.log -ns -sp 15


Xephyr / Xnest para abrir um Xwindow dentro de outro

Visual Git commands training

https://git-school.github.io/visualizing-git/#free

Access Remote Webcam (Take Picture and Live Stream), Access VNC Through SSH

Take picture on remote and display locally

ssh cloud_raspi 'fswebcam tapeiga.png && cat tapeiga.png' | display

Take screenshot on remote and display locally

ssh cloud_raspi 'DISPLAY=:0 scrot tapeiga2.png && cat tapeiga2.png' | display

Live video recording on remote and live display locally

ssh cloud_raspi ffmpeg -an -f video4linux2 -s 640x480 -i /dev/video0 -r 10 -b:v 500k -f matroska - | mplayer - -idle -demuxer matroska

Turn on TV connected on HDMI, on remote

ssh cloud_raspi 'vcgencmd display_power 1'

Turn off TV connected on HDMI, on remote

ssh cloud_raspi 'vcgencmd display_power 0'

Live Record Video Locally and Live Display on Remote TV
ffmpeg -an -f video4linux2 -s 640x480 -i /dev/video0 -r 10 -b:v 500k -f matroska - | ssh cloud_raspi 'DISPLAY=:0 mplayer - -idle -demuxer matroska'

Live Record Audio Remotelly and play Locally
ssh cloud_raspi "arecord -f cd -D plughw:1 | ffmpeg -ac 1 -i - -f ogg - " | mplayer - -idle -demuxer ogg
Live Record Audio Locally and Play on Remote
arecord -f cd -D plughw:1 | ffmpeg -ac 1 -i - -f ogg - | ssh cloud_raspi 'mplayer - -idle -demuxer ogg'
or

arecord -f cd | ssh cloud_raspi 'aplay'

or

arecord -f S16_LE -r 3600 | ssh cloud_raspi 'aplay'

Connect on VNC via cloud

On remote machine start VNC Server
and start a tunnel
ssh -R 6900:localhost:5900 user@mycloudserver.com

On local machine start a tunnel
ssh -L 5900:localhost:6900 user@mycloudserver.com
and connect vnc client to localhost
vncviewer localhost

ssh multiple hops / SSH Config

ssh -tt user_b@HOSTB ssh user_c@HOSTC -p 4567

ssh -J user_b@HOSTB,user_c@HOSTC user_d@HOSTD


Exemplos de ~/.ssh/config

------------------------------------------------------------------------------------------------------- user_a@HOSTA -> user_b@HOSTB:22 -> user_c@HOSTC:4567

Host *
   ControlPersist 18000
   ControlMaster auto
   TCPKeepAlive yes
   ServerAliveInterval 30


Host c_jump1
  User user_c
  Hostname HOSTC
  Port 4567
  ControlPath /tmp/ssjump1
  ProxyCommand ssh -W %h:%p user_b@HOSTB

Host c_jump2
  User user_c
  Hostname HOSTC
  Port 4567
  ControlPath /tmp/ssjump2
  ProxyCommand ssh user_b@HOSTB exec nc %h %p

------------------------------------------------------------------------------
user_a@HOSTA -> user_b@HOSTB:22 -> user_c@HOSTC:4567 -> user_d@HOSTD:7890

Host c_jump3
  Hostname HOSTD
  User user_d
  Port 7890
  ControlPath /tmp/ssjump3
  ProxyJump user_b@HOSTB:22,user_c@HOSTC:4567


-----------------------------------------------------------------------------
# man 5 ssh_config

https://www.systutorials.com/docs/linux/man/5-ssh_config/
http://www.openssh.com/txt/release-5.4

Transfer file through ssh connection using cat pipe

cat z.cpp | ssh user@hostname 'cat > /remote_folder/copy_of_z.cpp'

ssh user@hostname 'cat /remote_folder/copy_of_z.cpp' > z.cpp

Enable acess of internet connected to a VPN

nano /etc/sysctl.conf

Add or find and comment out the following line

net.ipv4.ip_forward=1

Save, close the file and run the following command to make the changes take effect.

sysctl -p

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

The following iptables firewall rules allow port 1723, GRE and perform NAT

iptables -I INPUT -p tcp --dport 1723 -m state --state NEW -j ACCEPT
iptables -I INPUT -p gre -j ACCEPT
iptables -t nat -I POSTROUTING -o eth0 -j MASQUERADE

In the last rule replace “eth0″ with the interface connecting to the internet on your VPN server. Finally the following rule is required to ensure websites load properly

iptables -I FORWARD -p tcp --tcp-flags SYN,RST SYN -s 172.20.1.0/24 -j TCPMSS  --clamp-mss-to-pmtu

Replace 172.20.1.0/24 with the IP address range used in the “remoteip” option in the /etc/pptpd.conf this firewall rule is used to ensure a proper MTU value is used to prevent fragmentation.

Auto Login with Python + SSH + Expect

Python and Expect

#!/usr/bin/python                                                                                                                     
import argparse
from ConfigParser import ConfigParser
import pexpect

def main(args):
    url = args.url
    user, host = url.split('@', 1)

    cfg_file = '/home/user/bala_python.passwords'
    cfg = ConfigParser()
    cfg.read(cfg_file)
    passwd = cfg.get(user, host)

    child = pexpect.spawn('ssh {0}'.format(url))
    child.expect('password:')
    child.sendline(passwd)
    child.interact()

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Run ssh through pexpect')
    parser.add_argument('url')
    args = parser.parse_args()
    main(args)

....
bala_python.passwords
[user1]
host1 = password1
host2 = password2

[user2]
host1 = password1
host2 = password2

PS | Script for Top equivalent command for AIX

#!/bin/sh

# If the shell script is stopped with CTRL+C, the screen
# might need to be sized correctly.

trap 'eval $(resize); exit 2' 2

# A loop to display activity.
while [ 1 ] ; do
eval $(resize)
#output=$(ps -eF "pcpu time pid user rssize comm" | grep -v TIME | sort -rn | head -$(("$LINES"-2)))
output=$(ps -eF "pcpu time pid user time etime rssize comm" | grep -v TIME | sort -rn | head -$(("$LINES"-2)))

echo ' %CPU TIME PID USER TIME ELAPSED RSS COMMAND'
echo "$output"
sleep 3
done
------------------------
ps -eof pid,cmd linux
ps -ef -o pid,args aix

ps f  # show ascii tree hierarchy

ps f -eo rss,ppid,pid,cmd   # shows memory process parent id, process id, comand and ascii hierarchy

ps faux # shows all process of all users and tree hierarchy

print all children of xrdp program
ps f -g $(ps -o sid= -p `pidof xrdp`)

pstree # show hierarchy with lines instead of slash and bars

http://meinit.nl/alternative-top-aix

Tcpdump

TCP Dump
----------------------------------------------------------------------------------
$ sudo tcpdump -s 0 -A host www.uol.com.br and port 80 #Show ASCII
$ sudo tcpdump -s 0 -X host www.uol.com.br and port 80 #Show Hexdump and ASCII

#Filter only packages in port range from 4210-4218, with tcp-flag Push, and do not buffer output with "-l" so I can pipe and don't freeze

$ sudo tcpdump -l -i eth0 -X -s 0 -n 'host snelnxa124 and portrange 4210-4218 and (tcp[tcpflags] & (tcp-push) != 0)'
$ sudo tcpdump -l -i eth0 -A -s 0 -n 'host snelnxa124 and portrange 4210-4218 and (tcp[tcpflags] & (tcp-push) != 0)' | grep -v Flags
$ sudo tcpdump -l -i eno1  -A -s 0 -n 'host www.ic.unicamp.br and tcp port http'

Extra
-----------------------------------------------------------------------------------
$ telnet towel.blinkenlights.nl #Star wars ascii

https://goo.gl/AwpNxV
https://fwknowledge.wordpress.com/2013/03/05/tcpdump-flags/
https://www.wains.be/pub/networking/tcpdump_advanced_filters.txt

Expect to login in ssh server through balabit

#!/usr/bin/expect -f

trap {
   set XZ [stty rows   ]
   set YZ [stty columns]
   stty rows $XZ columns $YZ < $spawn_out(slave,name)
} WINCH


proc getpass pwprompt {
       set oldmode [stty -echo -raw]
       send_user "\n     $pwprompt"
       set timeout -1
       expect_user -re "(.*)\n"
       send_user "\n"
       eval stty $oldmode
       return $expect_out(1,string)
}

set host [lrange $argv 0 0]

#Save Last Path ########
set last_path_file "/tmp/.save_bala_ssh_$host.txt"
if {[file exists $last_path_file]} {
       set f [open "/tmp/.save_bala_ssh_$host.txt"]
       set lp [split [read $f] "\n"]
       set last_path [lindex $lp 1]
       send_user "Last Path for host $host: $last_path\n"
       close $f
}
########################

#set user [lrange $argv 1 1]
set user "usuario_balabit"
set path [lrange $argv 1 1]
#set pass [getpass "Password: "]
set pass "senha_balabit"
set timeout -1
#spawn -noecho bash;
#send "ssh -A $host\r"
spawn ssh -t $host
set passwords { "senha1" "senha2" "senha3" }
set try 0
##
set timeout 2
expect {
       "Gateway username: " {
               send -- "$user\r"
               exp_continue
       }

       "Gateway password: " {
               send -- "$pass\r"
               exp_continue
       }

       "password:" {
               if { $try >= [llength $passwords] } {
                       send_error ">>> wrong passwords\n"
                               exit 1
               }
               send -- "[lindex $passwords $try]\r"
               incr try
               set timeout 3
               exp_continue
       }

       "denied" {
               set timeout 5
               exp_continue
       }

       timeout {
               #interact
               send_user "\nOK Cool! Finally Connected\n"
               if { $path != "" } {
                       if { $path != "-l" } {
                               send  -- "\nclear\ncd $path\n"
                       } else {
                               send  -- "\nclear\ncd $last_path\n"
                       }
               }
               #interact
               set CTRLZ \032
               interact {
                       -reset $CTRLZ {exec kill -STOP [pid]}
                       #\003   exit
                       #mostra_data {
                       #       send_user "The date is [exec date]."
                       #}
                       #foo {
                       #       send_user "bar"
                       #}
                       #\001   {send_user "you typed a control-A\n";
                       #       send "\001"
                       #}
                       #\002   {send_user "you typed a control-B\n";
                       #       send "\002"
                       #}
                       ç {
                               send "pwd\r"
                               expect "/*\n"
                               puts [open $last_path_file w] $expect_out(buffer)
                       }
               }
       }
}

Remove files with special characters

user@host $ ls -i
65649 file?name
user@host $ find . -inum 65649 -exec rm {} \;
./-.txt