nreplops-tool (nr)
nreplops-tool (nr) is a non-interactive nREPL client designed to be used in
shell scripts and on the command-line.
Early α warning: This project is still at a very early development phase. While the tool is probably reasonably usable (and the author uses it daily) the current development focus is not on quality, stability, or documentation.
Try it out in 1 minute
This example assumes you are able to install packages with Homebrew. See the Installation section below for other options.
Start by installing nreplops-tool (nr) and Babashka (bb):
brew install mjhanninen/sour/nreplops-tool borkdude/brew/babashka
Launch a Babashka nREPL server (that listens on the port 1667 by default):
bb nrepl-server
Open another terminal and evaluate an expression with nr:
nr -p 1667 -e '(println "Hello, world!")'
Quick examples
Before starting make sure that you have a Clojure nREPL server running in the
background and there is a corresponding .nrepl-port file in either the current
working directory or any of its ancestor.
Evaluate the expression (+ 1 2) on a nREPL server:
$ nr -e '(+ 1 2)'
3
Pass the expressions through a pipe:
$ echo '(+ 1 2)' | nr
3
Evaluate the content of a file:
$ echo '(+ 1 2)' > plus.clj
$ nr plus.clj
3
Create an executable nREPL scripts:
$ cat <<EOF > plus.nrepl
+ #!/usr/bin/env nr -!
+ (+ 1 2)
+ EOF
$ chmod +x plus.nrepl
$ ./plus.nrepl
3
Suppose the nREPL server had a function called get-user-by-email that searched
in retrieved users from the application database by email. A script exposing
that functionality to the command line could look something like this:
$ cat <<EOF > get-user-by-email.nrepl
+ #!/usr/bin/env nr -! --no-results
+ (clojure.pprint/pprint
+ (get-user-by-email db "#nr[1]"))
$ EOF
$ chmod +x get-user-by-email.nrepl
$ ./get-user-by-email.nrepl wile.e.coyote@example.com
{:name "Wile E. Coyote"
:email "wile.e.coyote@example.com"
:phone "555-555 555"}
Installation
Homebrew
brew install mjhanninen/sour/nreplops-tool
Cargo
cargo install nreplops-tool
Building from sources
git clone https://github.com/mjhanninen/nreplops-tool.git
cargo install --path .
Goals
- Easy of use in shell scripts
- Consistency and interoperability with selected CLI tools: Babashka, Jet, and jq
License
Copyright 2022 Matti Hänninen
Licensed under the Apache License 2.0