slavaganzin / 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

install

# recommended way (crossplatform)
eget slavaGanzin/await --to /usr/local/bin/

# nix
nix-shell -p await

# arch
yay -S await

# not recommended, but it works!
curl https://i.jpillora.com/slavaGanzin/await! | bash

completions

It's a single binary distribution, so you need to do it yourself (or download from a release)

# bash
await --autocomplete-bash > ~/.bashrc

#zsh
await --autocomplete-zsh > ~/.zshrc

#fish
await --autocomplete-fish > ~/.config/fish/completions/await.fish

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
  --version -v	#print the version of await
  --autocomplete-fish	#output fish shell autocomplete script
  --autocomplete-bash	#output bash shell autocomplete script
  --autocomplete-zsh	#output zsh shell autocomplete script


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"

await's Issues

How can I use it in script with bash functions?

 ╰─λ cat test.sh 
#!/bin/bash
function func {
echo 2
}
await 'echo 1' -e 'func'

 ╰─λ test.sh 
sh: line 1: func: command not found
⣷ echo 1

I've tried to pass function with different approaches, but no result. Is it possible to pass function (without using another scripts.sh files or writing entire commands in await) in my case?

Curl und run will never die

curl https://i.jpillora.com/slavaGanzin/await! | bash
This should never ever be done.
Make it worse, use | sudo bash

Please do not recommend this procedure

Invalid SSL cert on documentation website

Website documentation certificate problem:
https://await-cli.app/

The documentation website gives me an invalid certificate error:

Your connection isn't private
Attackers might be trying to steal your information from await-cli.app (for example, passwords, messages or credit cards).
NET::ERR_CERT_COMMON_NAME_INVALID

Completion of error handling

Would you like to add more error handling for return values from functions like the following?

• fopen ⇒ service
• malloc ⇒ replace

Error: No asset for platform darwin-amd64

When I try to install await on my M1 Macbook Pro it returns the following error:

curl https://i.jpillora.com/slavaGanzin/await! | bash
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  4581    0  4581    0     0   5812      0 --:--:-- --:--:-- --:--:--  5813
============
Error: No asset for platform darwin-amd64

Feature Request: Version flag

Hi, is it possible to add a version flag to the command line switch?
e.g.

await --version
1.0.2

Many thanks!

Feature request: Bash auto-completion

Availability via package managers

Hi Slava,

I just stumbled over await and it looks great!

It would be great if it would be available via platform independent package managers like Flathub or Snap.
And for OS/X users a brew package would be nice.

This way everybody could profit from automated updates.
Thank you so much! 🙌