GetoptLong

This is a command-line argument parser which wraps the powerful Perl module Getopt::Long and with some adaptations for easier use in R. It also provides a simple way for variable interpolation in R.

There are two vignettes in the package which explain in more detail:

1. Parsing command-line arguments by Getopt::Long
2. Simple variable interpolation

Install

The package can be installed from CRAN:

install.packages("GetoptLong")

or directly from GitHub:

devtools::install_github("jokergoo/GetoptLong")

Usage

Control command line options

This package wraps the powerful Perl module Getopt::Long and keeps almost all features of it. The syntax of option specification is the same as Getopt::Long. So if you are from Perl and you know Getopt::Long, there would be no difficulty with using it.

The usage is very simple:

library(GetoptLong)

cutoff = 0.05
GetoptLong(
    "number=i", "Number of items.",
    "cutoff=f", "Cutoff for filtering results.",
    "verbose!", "Print message."
)

Then you can run this script by:

~\> Rscript foo.R --number 4 --cutoff 0.01 --verbose
~\> Rscript foo.R --number=4 --cutoff=0.01 --no-verbose
~\> Rscript foo.R -n 4 -c 0.01 -v
~\> Rscript foo.R -n 4 --verbose

Help message is automatically generated:

Usage: Rscript foo.R [options]

Options:
  --number, -n integer
    Number of items.
 
  --cutoff, -c numeric
    Cutoff for filtering results.
    [default: 0.05]
 
  --verbose
    Print message.
 
  --help, -h
    Print help message and exit.
 
  --version
    Print version information and exit.

Variable interpolation

This package also supports simple variable interpolation, which means you can embed variables into texts directly, just like in Perl.

r = c(1, 2)
value = 4
name = "name"
qq("region = (@{r[1]}, @{r[2]}), value = @{value}, name = '@{name}'")

## [1] "region = (1, 2), value = 4, name = 'name'"

So it would be much easier for you to construct complicated texts instead of using paste().

License

MIT @ Zuguang Gu