#parallel #shell

app async-cmd

A tool to run shell commands in parallel

1 unstable release

0.1.1 Jun 27, 2019
0.1.0 Jun 27, 2019

#76 in #parallel


562 lines


async is a tool to run shell commands in parallel and is designed to be able to quickly parallelize shell scripts with minimal changes. It was inspired by GNU Parallel, with the main difference being that async retains state between commands by running a server in the background.


All information about the command line interface is available using async --help. Below is an example on how to use async to parallelize commands:


async -s="$S" server --start

for i in {1..20}; do
    # prints command output to stdout
    async -s="$S" cmd -- bash -c "sleep 1 && echo test $i"

# wait until all commands are finished
async -s="$S" wait

# configure the server to run four commands in parallel
async -s="$S" server -j4

mkdir "/tmp/ex_dir"
for i in {21..40}; do
    # redirects command output to /tmp/ex_dir/file*
    async -s="$S" cmd -o "/tmp/ex_dir/file$i" -- bash -c "sleep 1 && echo test $i"

async -s="$S" wait

# stops server
async -s="$S" server --stop

If you encounter an unexpected error or crash, please turn on logging by setting the environment variable RUST_LOG=debug and open an issue on the Github repository.


async can be installed using cargo with cargo install async-cmd or from the AUR.


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