Links: Source | crates.io

checkexec is a tool to conditionally execute commands based on modified timestamps of a target and a dependency list.

checkexec pairs well with just to offer a modular and modern build process and command runner toolkit. just fixes numerous problems with make, and checkexec adds back the conditional rebuild functionality of make.

Why not use make?

make has numerous usability problems which are discussed on the just Readme. make also violates the single responsibility principle by being both a build recipe tool and a dependency manager. just solves that problem, but it does not have built-in functionality to resolve dependencies. checkexec fills that gap.

Use cases

checkexec is great for when you build files from other files. Instead of relying on an ecosystem specific tool, you can use checkexec as part of any build tool. Here are some examples:

• You build images as part of your build command, and don't want to recompile them unless you need to.
• You build C libaries as part of your Python, Rust, Node (or any other) build process.
• You build Sass/Less/SCSS files and don't want to re-build them unnecessarily.

Installation

cargo install checkexec

Usage

Here's a simple example to compile a c program only if its source file has been updated.

checkexec build/my-c-program src/my-c-program.c -- cc -o build/my-c-program src/my-c-program.c

By default, checkexec executes the command directly, not in a shell. If you want to use a shell, specify it explicitly.

checkexec build/my-c-program src/my-c-program.c -- /bin/bash "cc -o build/my-c-program src/my-c-program.c && cp build/my-c-program /usr/local/bin/my-c-program"

Now, let's see checkexec in a Justfile.

# Justfile
build:
    checkexec target/debug/myprogram src/main.rs -- cargo build

Using this file, just build will only build the program if the source file has been updated, whereas the default cargo build usage will always build the program.