README.md

In kevinushey/RCLI: A Simple Rscript Argument Parser

RCLI

This is a lightweight, very opinionated package for generating R scripts that can be run from the command line using Rscript. It allows us to generate scripts with a minimal amount of boilerplate for nicer usage from the command line.

Using this package, we can write R scripts of the form (say in a file echo.R):

#!/usr/bin/env Rscript

library(RCLI)
description("A simple script that echos its arguments.")
usage("Takes arguments of the form 'a=b', and outputs the variable name 'a' and the value 'b'.")
args <- parse_args()

if( length(args) == 0 ) {
  print_description()
  print_usage()
}

for( i in seq_along(args) ) {
  arg <- args[[i]]
  name <- names(args)[i]
  cat("Argument number ", i, " has name ", name, " and value ", arg, ".\n", sep="")
}

Then one could run this from the command line as either:

Rscript echo.R a=1 b=2 c=3

or, with +x permissions:

echo.R a=1 b=2 c=3

One can also get the description and usage information printed out using -h or --help as a command line argument; this is currently the only - style argument supported.

echo.R --help

prints

Description: A simple script that echos its arguments. 
Usage: Takes arguments of the form 'a=b', and outputs the variable name 'a' and the value 'b'.

Note that it is (currently) a requirement that all arguments are passed as named arguments; this may change in the future, however, I prefer a strict simplicity over complexity of other solutions.

kevinushey/RCLI documentation built on May 20, 2019, 9:08 a.m.