bash #linux #bash

Reload bash profile source ~/.bash_profile
Display environment variable echo $VARNAME
Dir by date ls -Ghaltr
Copy with SCP scp username@host:/some/remote/dir/\{a,b,c} ./
Copy with SCP scp {foo,bar}.txt username@host:/some/remote/dir/
Generate SHA256 hash openssl sha -sha256 <file>
Status of network interfaces netstat -i (Local, Broadcast, Multicast, Promiscuous, Running, Up)
Set network promiscous mode ifconfig eth0 promisc
Show physical and logical network devices iw dev
Map logical network device to physical iw phy phy0 interface add mon0 type monitor
Update expired Kali repo keys wget -q -O - https://archive.kali.org/archive-key.asc | apt-key add
Biggest files and directories du -ah /home | sort -hr | head -n 5
IP Address on login screen - Add to /etc/issues eth0: \4{eth0}
Auto refresh a command - watch [command]
CentOS DeltaRPM - yum install deltarpm
Shell loop - for f in *.txt; do echo "Processing $f file..."; done
Byte revers file - < file.gnp xxd -p -c1 | tac | xxd -p -r > file.png

/dev/tcp/host/port
    If host is a valid hostname or Internet address, and port is an integer port number
    or service name, bash attempts to open a TCP connection to the corresponding socket.

/dev/udp/host/port
    If host is a valid hostname or Internet address, and port is an integer port number
    or service name, bash attempts to open a UDP connection to the corresponding socket.

xenon-lornix:~> cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_6.2p2 Debian-6
^C pressed here

Profiles Understanding .bashrc and .bash_profile
/etc/profile is a global file that gets run before ~/.profile
/etc/profile.d/ is a folder that contains scripts called by /etc/profile
When /etc/profile is called (when you start/login a shell), it searches for any files ending in .sh in /etc/profile.d/ and runs them with one of these commands:
- source /etc/profile.d/myfile.sh
- . /etc/profile.d/myfile.sh
  Putting 00- before the file name to make it execute before the rest of the scripts.
  You can also add your aliases in /etc/profile, but this isn't recommended.
30 Handy Bash Shell Aliases
10 Handy Bash Aliases
Convert EPOCH time - date -d @<timestamp>
Recursive Hashing - `find ./dir/ -type f -exec sha1sum {} \; > files.sha1
Recursive Hashing 2 - `find ./dir/ -type f -print0 | xargs -0 sha1sum > /files.sha1
Recursive Hashing 3 - shopt -s globstar dotglob; sha1sum ** (Sets variables "globstar" for recursive match on **, and "dotglob" to enable matching hidden files)
Time a command runtime - time <command> (Returns real/user/sys times)
Set default editor - export VISUAL=vim; export EDITOR="$VISUAL"
Test if is running from shell script

if !(systemctl -q is-active <service> )
    then
    echo "Service is not running."
    exit 1
fi

Test if user is running as root from shell script

if [[ $EUID -ne 0 ]]
    then
    echo "Must be run as root."
    exit 1
fi

interface to promiscuous mode:

  ip link set eth1 promisc on
  ifconfig eth1 promisc

 Flags BMPRU will be updated:
  B	Broadcast
  M Multicast
  P Promiscuous
  R Running
  U Up

cactaceae21/information.md