Spinner

_spinner.md

Tip

for ansicolor, either using \033[XXm directly, or use following c() function as below:

# credit: https://github.com/ppo/bash-colors
# author: @ppo
# shellcheck disable=SC2015,SC2059
c() { [ $# == 0 ] && printf "\e[0m" || printf "$1" | sed 's/\(.\)/\1;/g;s/\([SDIUFNHT]\)/2\1/g;s/\([KRGYBMCW]\)/3\1/g;s/\([krgybmcw]\)/4\1/g;y/SDIUFNHTsdiufnhtKRGYBMCWkrgybmcw/12345789123457890123456701234567/;s/^\(.*\);$/\\e[\1m/g'; }

Braille Patterns Spinner

1-dot

local spinner=( '⠁' '⠂' '⠄' '⡀' '⢀' '⠠' '⠐' '⠈' )

---

4-dots

local spinner=( '⣄' '⣆' '⡇' '⠏' '⠋' '⠹' '⢸' '⣰' '⣠' )

---

local spinner=(
  "$(c Rs)⣄$(c)"
  "$(c Ys)⣆$(c)"
  "$(c Gs)⡇$(c)"
  "$(c Bs)⠏$(c)"
  "$(c Ms)⠋$(c)"
  "$(c Ys)⠹$(c)"
  "$(c Gs)⢸$(c)"
  "$(c Bs)⣰$(c)"
  "$(c Ms)⣠$(c)"
)

---

7-dots

local spinner=( '⣾' '⣽' '⣻' '⢿' '⡿' '⣟' '⣯' '⣷' '⣿' )

---

local spinner=(
  "$(c Rs)⣾$(c)"
  "$(c Ys)⣽$(c)"
  "$(c Gs)⣻$(c)"
  "$(c Cs)⢿$(c)"
  "$(c Rs)⡿$(c)"
  "$(c Ys)⣟$(c)"
  "$(c Gs)⣯$(c)"
  "$(c Cs)⣷$(c)"
  )

---

others

local spinner=(
  "∙∙∙∙∙"
  "$(c Ys)●$(c)∙∙∙∙"     # yellow
  "∙$(c Gs)●$(c)∙∙∙"     # green
  "∙∙$(c Cs)●$(c)∙∙"     # cyan
  "∙∙∙$(c Bs)●$(c)∙"     # blue
  "∙∙∙∙$(c Ms)●$(c)"     # magenta
)

---

local spinner=(
  "$(c Rs)∙∙∙∙∙$(c)"     # red
  "$(c Ys)●∙∙∙∙$(c)"     # yellow
  "$(c Gs)∙●∙∙∙$(c)"     # green
  "$(c Cs)∙∙●∙∙$(c)"     # cyan
  "$(c Bs)∙∙∙●∙$(c)"     # blue
  "$(c Ms)∙∙∙∙●$(c)"     # magenta
)

---

local spinner=( '∙∙∙∙∙' '●∙∙∙∙' '∙●∙∙∙' '∙∙●∙∙' '∙∙∙●∙' '∙∙∙∙●' )

spinner-with-exitcode.sh

#!/usr/bin/env bash

# credit: https://github.com/ppo/bash-colors
# shellcheck disable=SC2015,SC2059
c() { [ $# == 0 ] && printf "\e[0m" || printf "$1" | sed 's/\(.\)/\1;/g;s/\([SDIUFNHT]\)/2\1/g;s/\([KRGYBMCW]\)/3\1/g;s/\([krgybmcw]\)/4\1/g;y/SDIUFNHTsdiufnhtKRGYBMCWkrgybmcw/12345789123457890123456701234567/;s/^\(.*\);$/\\e[\1m/g'; }

# capture ctrl-c to exit the sub-process
function withSpinner() {
  local msg="$1"; shift
  local __resultvar="$1"; shift
  local spinner=(
    "$(c Rs)⣄$(c)"
    "$(c Ys)⣆$(c)"
    "$(c Gs)⡇$(c)"
    "$(c Bs)⠏$(c)"
    "$(c Ms)⠋$(c)"
    "$(c Ys)⠹$(c)"
    "$(c Gs)⢸$(c)"
    "$(c Bs)⣰$(c)"
    "$(c Ms)⣠$(c)"
  )
  local frame=0
  local output
  local cmdPid
  local pgid=""
  local interrupted=0

  # explicit recovery cursor
  function restoreCursor() { printf "\033[?25h" >&2; }

  # ensure that any exit restores the cursor.
  trap 'restoreCursor' EXIT

  # hide cursor
  printf "\033[?25l" >&2
  printf "%s " "${msg}" >&2

  set -m
  trap 'interrupted=1; [ -n "${pgid}" ] && kill -TERM -- -${pgid} 2>/dev/null' INT

  # shellcheck disable=SC2034,SC2030
  output="$(
    {
      "$@" 2>/dev/null &
      cmdPid=$!
      pgid=$(ps -o pgid= ${cmdPid} | tr -d ' ')
      echo "${pgid}" > "${tmpfile}"

      while kill -0 "$cmdPid" 2>/dev/null && (( interrupted == 0 )); do
        printf "\r\033[K%s %b" "${msg}" "${spinner[frame]}" >&2
        ((frame = (frame + 1) % ${#spinner[@]}))
        sleep 0.1
      done

      wait "${cmdPid}" 2>/dev/null
    }
  )"

  # \r : beginning of line
  # \033[K : clear current position to end of line
  if (( interrupted )); then
    printf "\r\033[K\033[31m✗\033[0m Interrupted!\033[K\n" >&2
    # shellcheck disable=SC2031
    [ -n "${pgid}" ] && kill -TERM -- -"${pgid}" 2>/dev/null
  else
    printf "\r\033[K\033[32m✓\033[0m Done!\033[K\n" >&2
  fi

  # a separate recovery cursor is no longer required because the exit trap is handled
}

# main function
function main() {
  tmpfile=$(mktemp)
  trap 'rm -f "${tmpfile}"' EXIT

  withSpinner "Loading..." result sleep 5
  echo "Exit code: $?"
}

main "$@"

# vim:tabstop=2:softtabstop=2:shiftwidth=2:expandtab:filetype=sh:

spinner-with-stdout.sh

#!/usr/bin/env bash

# credit: https://github.com/ppo/bash-colors
# shellcheck disable=SC2015,SC2059
c() { [ $# == 0 ] && printf "\e[0m" || printf "$1" | sed 's/\(.\)/\1;/g;s/\([SDIUFNHT]\)/2\1/g;s/\([KRGYBMCW]\)/3\1/g;s/\([krgybmcw]\)/4\1/g;y/SDIUFNHTsdiufnhtKRGYBMCWkrgybmcw/12345789123457890123456701234567/;s/^\(.*\);$/\\e[\1m/g'; }

# capture ctrl-c to exit the sub-process
# return the sub-process stdout ( to external variable )
function withSpinner() {
  local msg="$1"; shift
  local __resultvar="$1"; shift
  local spinner=(
    "$(c Rs)⣾$(c)"
    "$(c Ys)⣽$(c)"
    "$(c Gs)⣻$(c)"
    "$(c Cs)⢿$(c)"
    "$(c Rs)⡿$(c)"
    "$(c Ys)⣟$(c)"
    "$(c Gs)⣯$(c)"
    "$(c Cs)⣷$(c)"
  )
  local frame=0
  local output
  local cmdPid
  local pgid=''
  local interrupted=0

  # define the cursor recovery function
  restoreCursor() { printf "\033[?25h" >&2; }

  # make sure that any exit restores the cursor
  trap 'restoreCursor' EXIT

  # hide cursor
  printf "\033[?25l" >&2
  printf "%s " "$msg" >&2

  set -m
  trap 'interrupted=1; [ -n "$pgid" ] && kill -TERM -- -$pgid 2>/dev/null' INT

  # use file descriptor to capture output
  local tmpout
  tmpout=$(mktemp)
  exec 3<> "${tmpout}"

  # shellcheck disable=SC2031,SC2030
  output="$(
    {
      # execute command and redirect output to file descriptor 3
      "$@" >&3 2>/dev/null &
      cmdPid=$!
      pgid=$(ps -o pgid= "$cmdPid" | tr -d ' ')

      # update the spinner while the command is running
      while kill -0 "$cmdPid" 2>/dev/null && (( interrupted == 0 )); do
        printf "\r\033[K%s %b" "${msg}" "${spinner[frame]}" >&2
        ((frame = (frame + 1) % ${#spinner[@]}))
        sleep 0.08
      done

      wait "$cmdPid" 2>/dev/null
      # show the captured content
      cat "${tmpout}"
    }
  )"

  # clean the temporary file
  exec 3>&-
  rm -f "${tmpout}"

  # \r : beginning of line
  # \033[K : clear current position to end of line
  # shellcheck disable=SC2031
  if (( interrupted )); then
    printf "\r\033[K\033[31m✗\033[0m Interrupted!\033[K\n" >&2
    [ -n "${pgid}" ] && kill -TERM -- -"${pgid}" 2>/dev/null
  else
    # or using `printf "\r" >&2` directly without sub-progress status output
    printf "\r\033[K\033[32m✓\033[0m Done!\033[K\n" >&2
  fi

  # assign the result to an external variable
  printf -v "$__resultvar" "%s" "$output"
}

function main() {
  # shellcheck disable=SC2155
  local tmpfile=$(mktemp)
  trap 'rm -f "${tmpfile}"' EXIT

  local response
  withSpinner "Loading..." response \
    curl -s https://<API> ...

  # check curl output
  echo "${response}" 
}

main "$@"

# vim:tabstop=2:softtabstop=2:shiftwidth=2:expandtab:filetype=sh: