slw287r / await

28Kb, small memory footprint, single binary that run list of commands in parallel and waits for their termination

await

28Kb, small memory footprint, single binary that run list of commands in parallel and waits for their termination

documentation

linux install

curl https://i.jpillora.com/slavaGanzin/await! | bash

With await you can:

Take action on specific file type changes

await 'stat **.c' --change --forever --exec 'gcc *.c -o await -lpthread'
# you can filter with:
`stat --format '%n %z' **; | grep -v node_modules`

Wait for FAANG to fail

await 'whois facebook.com' \
      'nslookup apple.com' \
      'dig +short amazon.com' \
      'sleep 1 | telnet netflix.com 443 2>/dev/null' \
      'http google.com' --fail

Notify yourself when your site down

await "curl 'https://whatnot.ai' &>/dev/null && echo UP || echo DOWN" \
      --forever --change --exec "ntfy send 'whatnot.ai \1'"

Use as concurrently

await "stylus --watch --compress --out /home/vganzin/work/whatnot/front /home/vganzin/work/whatnot/front/index.styl" \
      "pug /home/vganzin/work/whatnot/front/index.pug --out /home/vganzin/work/whatnot/front --watch --pretty 2>/dev/null" --forever --stdout --silent

Substitute while substituting

await 'echo -n 10' 'echo -n $RANDOM' 'expr \1 + \2' --exec 'echo \3' --forever --silent

Furiously wait for new iPhone in background process

await 'curl "https://www.apple.com/iphone/" -s | pup ".hero-eyebrow text{}" | grep -v 12' --interval 1000 --change --daemon --exec 'ntfy send "\1"'

Restart database and connect immediately after it become fully functional

sudo systemctl restart redis; await 'socat -u OPEN:/dev/null UNIX-CONNECT:/tmp/redis.sock' --exec 'redis-cli -s /tmp/redis.sock'

--help

await [arguments] commands

# runs list of commands and waits for their termination

OPTIONS:
  --help	#print this help
  --stdout -o	#print stdout of commands
  --silent -V	#do not print spinners and commands
  --fail -f	#waiting commands to fail
  --status -s	#expected status [default: 0]
  --any -a	#terminate if any of command return expected status
  --change -c	#waiting for stdout to change and ignore status codes
  --exec -e	#run some shell command on success;
  --interval -i	#milliseconds between one round of commands [default: 200]
  --forever -F	#do not exit ever
  --service -S	#create systemd user service with same parameters and activate it


NOTES:
# \1, \2 ... \n - will be subtituted with n-th command stdout
# you can use stdout substitution in --exec and in commands itself:
  await 'echo -n 10' 'echo -n $RANDOM' 'expr \1 + \2' --exec 'echo \3' --forever --silent


EXAMPLES:
# action on specific file type changes
 await 'stat **.c' --change --forever --exec 'gcc *.c -o await -lpthread'

# waiting google (or your internet connection) to fail
  await 'curl google.com' --fail

# waiting only google to fail (https://ec.haxx.se/usingcurl/usingcurl-returns)
  await 'curl google.com' --status 7

# waits for redis socket and then connects to
  await 'socat -u OPEN:/dev/null UNIX-CONNECT:/tmp/redis.sock' --exec 'redis-cli -s /tmp/redis.sock'

# lazy version
  await 'ls /tmp/redis.sock'; redis-cli -s /tmp/redis.sock

# daily checking if I am on french reviera. Just in case
  await 'curl https://ipapi.co/json 2>/dev/null | jq .city | grep Nice' --interval 86400

# Yet another server monitor
  await "curl 'https://whatnot.ai' &>/dev/null && echo 'UP' || echo 'DOWN'" --forever --change\
    --exec "ntfy send \'whatnot.ai \1\'"

# waiting for new iPhone in daemon mode
  await 'curl "https://www.apple.com/iphone/" -s | pup ".hero-eyebrow text{}" | grep -v 12'\
 --change --interval 86400 --daemon --exec "ntfy send \1"