если бла-бла-бла (вывод) | grep <expression> то выполнить <cmd>

echo "123" >/dev/tcp/127.0.0.1/7777

>/dev/tcp/127.0.0.1/23
bash: connect: Connection refused
bash: /dev/tcp/127.0.0.1/23: Connection refused

cut -c 140-240 file

hostname -I

cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 10 | sed 1q
base64 -w 15 /dev/urandom | head

? d????????? ? ? ? ?            ? .
? d????????? ? ? ? ?            ? ..
? -????????? ? ? ? ?            ? gpg.conf
? d????????? ? ? ? ?            ? openpgp-revocs.d
? -????????? ? ? ? ?            ? pubring.kbx
? -????????? ? ? ? ?            ? pubring.kbx~
? -????????? ? ? ? ?            ? trustdb.gpg

chmod -R a+X /path/to/folder

<SOME_DATA> | awk '{s+=$1}END{print s}'

nice find ./ -type f -mtime +365 | xargs du | awk '{ t+=$1 } END { print t }'

find ./ -type f -mtime +365 -exec ls {} \; 

nice find ./ -type f -mtime +365 -exec rm {} \; 

cmd=$(ps aux)
printf "%s\n" "$cmd"

kubectl ()
{
  PS1="\e[1;31m $(/usr/bin/kubectl config current-context) \e[m \[\e]0;\u@\h: \w\a\]\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]$ "
  if [[ "$#" == "0" ]]; then return; fi
  /usr/bin/kubectl "$@"
  PS1="\e[1;31m $(/usr/bin/kubectl config current-context) \e[m \[\e]0;\u@\h: \w\a\]\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]$ "
}

helm ()
{
  PS1="\e[1;31m $(/usr/bin/kubectl config current-context) \e[m \[\e]0;\u@\h: \w\a\]\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]$ "
  if [[ "$#" == "0" ]]; then return; fi
  read -p "Context $(tput setaf 1)$(/usr/bin/kubectl config current-context)$(tput sgr 0) is proper? [Y/n]: " userinput
  if [[ ! "$userinput" == "" ]]; then return; fi
  /usr/local/bin/helm "$@"
}

for i in $(ls *.back); do echo $i is now ${i/back/hi-bo0om}; done
1.2.back is now 1.2.hi-bo0om
3.4.back is now 3.4.hi-bo0om
5.6.back is now 5.6.hi-bo0om

find -type f -name "*.html~" |
while read f; do
    mv "$f" "${f%\~}"
done

for i in $(ls *.back); do basename $i .back; done

basename -s .back $(find ./ -name *.back)