tricky

process bar

reference:
How to add a progress bar to a shell script?

with dot `.`

reference:
colorful output : c()
c() can be also found in .marslorc

while true; do
  (( i++ == 0 )) && printf $(c sY)%-6s$(c) 'waiting ...' || printf $(c sY)%s$(c) '.'
  sleep 1
done

with `▉ ▎ ▌ ▊`

another:
A progress bar for the shell

# main function designed for quickly copying to another program
progressBar() {
  Bar=""                                  # Progress Bar / Volume level
  Len=25                                  # Length of Progress Bar / Volume level
  Div=4                                   # Divisor into Volume for # of blocks
  Fill="▒"                                # Fill up to $Len
  Arr=( "▉" "▎" "▌" "▊" )                 # UTF-8 left blocks: 7/8, 1/4, 1/2, 3/4

  FullBlock=$((${1} / Div))               # Number of full blocks
  PartBlock=$((${1} % Div))               # Size of partial block (array index)

  while [[ $FullBlock -gt 0 ]]; do
      Bar="$Bar${Arr[0]}"                 # Add 1 full block into Progress Bar
      (( FullBlock-- ))                   # Decrement full blocks counter
  done

  # if remainder zero no partial block, else append character from array
  if [[ $PartBlock -gt 0 ]]; then Bar="$Bar${Arr[$PartBlock]}"; fi

  # Pad Progress Bar with fill character
  while [[ "${#Bar}" -lt "$Len" ]]; do Bar="$Bar$Fill"; done

  echo progress : "$1 $Bar"
  exit 0                                  # Remove this line when copying into program
} # progressBar

Main () {
  tput civis                              # Turn off cursor
  for ((i=0; i<=100; i++)); do
    CurrLevel=$(progressBar "$i")         # Generate progress bar 0 to 100
    echo -ne "$CurrLevel"\\r              # Reprint overtop same line
    sleep .04
  done
  echo -e \\n                             # Advance line to keep last progress
  echo "$0 Done"
  tput cnorm                              # Turn cursor back on
} # main

Main "$@"

with `[###----]`

another solution:
fearside/ProgressBar

BAR='##############################'
FILL='------------------------------'
totalLines=100
barLen=30
count=0

while [ ${count} -lt ${totalLines} ]; do
  # update progress bar
  count=$(( ${count}+ 1 ))
  percent=$(( (${count} * 100 / ${totalLines} * 100)/ 100 ))
  i=$(( ${percent} * ${barLen} / 100 ))
  echo -ne "\r[${BAR:0:$i}${FILL:$i:barLen}] ${count}/${totalLines} (${percent}%)"
  sleep .1
done

with `|\|/`

while :; do
  for s in / - \\ \|
    do printf "\r$s"
    sleep .1
  done
done

Integralist/python progress bar.py

save & restore screen

reference
Terminal codes (ANSI/VT100) introduction

`tput`

clear
```
$ tput smcup
```
restore
```
$ tput rmcup
```

`echo`

save
```
$ echo -e '\033[?47h'
```
restore
```
$ echo -e '\033[?47l'
```

terminfo escape sequences

$ infocmp
  ...
  colors#256, cols#80, it#8, lines#24, pairs#32767,
  bel=^G, blink=\E[5m, bold=\E[1m, cbt=\E[Z, civis=\E[?25l,
  clear=\E[H\E[2J, cnorm=\E[?12l\E[?25h, cr=^M,
  ...

`tput`

reset terminal

[!NOTE]
Shell does not show typed-in commands, what do I do to fix it?

$ reset
# or
$ stty sane

clear screen

$ tput home

# or
$ tput cup %py %px
# or
$ tput cup %py %px >/dev/null

show term

$ tput color

show terminal width

$ tput cols

customized colorful output

references:
imarslo: highlight output

$ export GREP_COLORS="sl=0;33;49:ms=1;34;49"
$ find /etc/ -type f | head | grep --color=always '^\|[^/]*$'

`Operation not permitted`

[!NOTE|label:references:]
How to Fix 'rm: cannot remove '/etc/resolv.conf': Operation not permitted'
Can not edit resolv.conf
Un-removable /etc/resolv.conf
mac equivalent
chflags
/bin/ls -lO
$ /bin/ls -lO
total 288
-rwxr-xr-x@  1 marslo  staff  compressed,dataless 1116834851 Feb 21 17:00 Ubuntu2204-221101.AppxBundle

$ sudo lsattr /etc/resolv.conf
----i-------------- /etc/resolv.conf
$ sudo rm -rf /etc/resolv.conf
rm: cannot remove '/etc/resolv.conf': Operation not permitted

# solution
$ sudo chattr -i /etc/resolv.conf
$ sudo lsattr /etc/resolv.conf
------------------- /etc/resolv.conf
$ sudo mv /etc/resolv.conf{,.bak}

# revert back
$ sudo chattr +i /etc/resolv.conf
$ sudo lsattr /etc/resolv.conf
----i-------------- /etc/resolv.conf