interestingShell

#!bin/sh

# check the validation of commands
_=$(command -v docker);
if [ "$?" != "0" ]; then
  printf -- 'You do not seem to have Docker installed.\n';
  printf -- 'Get it: https://www.docker.com/community-edition\n';
  printf -- 'Exiting with code 127...\n';
  exit 127;
fi;

# show the process with animation
# for more related info, refer to  http://mywiki.wooledge.org/BashFAQ/034
printf -- 'Performing asynchronous action..';
./trigger-action;
DONE=0;
while [ $DONE -eq 0 ]; do
  ./async-checker;
  if [ "$?" = "0" ]; then DONE=1; fi;
  printf -- '.';
  sleep 1;
done;
printf -- ' DONE!\n';

# customize output with specific colors
# for more related info, refer to https://misc.flogisoft.com/bash/tip_colors_and_formatting
printf -- 'doing something... \n';
printf -- '\033[37m someone elses output \033[0m\n';
printf -- '\033[32m SUCCESS: yay \033[0m\n';
printf -- '\033[33m WARNING: hmm \033[0m\n';
printf -- '\033[31m ERROR: fubar \033[0m\n';

# choose specific exit code
if [ "$?" != "0" ]; then
  printf -- 'X happened. Exiting with status code 1.\n';
  exit 1;
fi;
# ...
if [ "$?" != "0" ]; then
  printf -- 'Y happened. Exiting with status code 2.\n';
  exit 2;
fi;