sharkdp / lucid

A simple mock-application for programs that work with child processes

lucid

A simple mock-application that can be used by other programs that work with child processes.

lucid is similar to sleep, but has a few additional features that can be helpful when debugging applications that spawn subprocesses.

Demo

Introduction

Applications or scripts that handle child processes need to deal with a lot of different scenarios.

There are really simple processes that successfully terminate after a short period of time:

lucid 2

Others also finish after some time, but fail with a non-zero exit code:

lucid 3 --exit-code=1

Some processes just run forever (but can be terminated via SIGINT or SIGTERM):

lucid

Others refuse to handle termination signals properly and just ignore them:

lucid 10 --no-interrupt

There are also processes that choose to daemonize themselves immediately:

lucid 10 --daemon

Many processes print a lot on standard output:

lucid 10 --verbose

While some others might generate error messages:

lucid 10 --stderr --verbose

Usage

USAGE:
    lucid [OPTIONS] [duration]

OPTIONS:
    -c, --exit-code <CODE>    Terminate with the given exit code [default: 0]
    -d, --daemon              Daemonize the process after launching
    -I, --no-interrupt        Do not terminate when receiving SIGINT/SIGTERM signals
    -p, --prefix <PREFIX>     Prefix all messages with the given string [default: lucid]
    -v, --verbose             Be noisy
    -q, --quiet               Do not output anything
    -e, --stderr              Print all messages to stderr
    -h, --help                Prints help information
    -V, --version             Prints version information

ARGS:
    <duration>    Sleep time in seconds. If no duration is given, the process will sleep forever.

Installation

On Debian-based systems

wget "https://github.com/sharkdp/lucid/releases/download/v0.3.0/lucid_0.3.0_amd64.deb"
sudo dpkg -i lucid_0.3.0_amd64.deb

On other distrubutions

Check out the release page for binary builds.

Via cargo

cargo install lucid

lucid's Issues

Add option to print to stderr by default

Add possibility to daemonize itself

Add --exit-code <code> option

Add --name or --prefix option to prefix all output

Add option to sleep indefinitely

Print status information (in verbose mode)

Print things like:

• lucids own PID
• Whether or not stdin, stdout and stderr are connected to an interactive terminal.
• start and end timestamps

Make cycle-time configurable

Show some output by default, but add --quiet