Batch-cmd NPM | npm.io

batch-cmd

Executing multiple commands in batches concurrently. It provides useful command-line tools and can also be imported as a library in JS (ESM).

Installation

You can install it directly from npm:

npm install batch-cmd

Command-line Usage

This repo provides two tools, bcmd and bssh. The first one is used for running general shell commands, while the second one is more conveniently for running commands on remote machines via SSH.

Both tools will handle OS signals in the following way:

Upon receiving the first SIGINT / SIGTERM: the program will send SIGTERM to all running commands and wait for them to stop.
Upon receiving the second SIGINT / SIGTERM: the program will send SIGKILL to force kill all running commands.
Upon receiving more than two SIGINT / SIGTERM: the program itself will exit forcefully.

Both tools will pass input from stdin to stdin of all the commands. It will also collect stdout / stderr from all commands and output in the stdout / stderr, with a prefix to distinguish them.

bcmd

# running 3 commands with 3 variables (-- is used to separate options from command)
# variables can be used in the template command (must be quoted)
bcmd -v A B C -- "echo {}"
# multiple variables can be used for each command by specifying a separator
bcmd -v A:1 B:2 C:2 -s ":" -- "echo {0} {1}"
# read variables from a file (can be combined with -v option)
bcmd -f vars.txt -- "mkdir {0} && echo {0}"
# pipe input to all commands
echo 'var' | bcmd -v A B C -- "cat -"

For more usage, please see bcmd -h.

bssh

bssh is similar to bcmd but more convenient to run command on remote machines. The first variable for each command must be the address of the remote machine.

# running 3 commands with 3 variables (-- is used to separate options from command)
# variables can be used in the template command (must be quoted)
bssh -v host1 host2 host3 -- "ls"
# multiple variables can be used for each command by specifying a separator
# note: the first argument is consumed internally using {0}, so other placeholders must be numbered as well
bssh -v host1:A host2:B -s ":" -- "echo {1}"
# read variables from a file (can be combined with -v option)
bssh -f hosts.txt -v host3 host4 -- "echo {0}"
# pipe input to all commands
echo 'var' | bssh -v host1 host2 -- "cat -"

For more usage, please see bssh -h.

Library Usage

This repo also exports a JS (ESM) library (with type declarations). Example usage:

import { CommandExecutor, runExecutor } from "../src/lib.js";

const executor = new CommandExecutor([
  ["a", "1"],
  ["b", "2"],
  ["c", "3"]
]);
await runExecutor(executor, "echo From {0}: {1}", ":");

Changelog

See CHANGELOG.md.

License

This project is licensed under AGPL-3.0.

Copyright (C) 2023 DCsunset
This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.