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This is yet another command-line argument parser which wraps the powerful Perl module Getopt::Long and with some adaptation 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 in R

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 as same as Getopt::Long. So if you are coming from Perl and you know Getopt::Long, there would be no difficulty with using it.

Also, this package supports default values, imports option names into working environment, and automatically generates help messages. The usage is very simple:

cutoff = 0.05  # cutoff has default value and not necessary to specify in command line
    "cutoff=f", "cutoff of something (default is 0.05)",
    "input=s%", "input file",
    "verbose!", "print messages"

Then you can run this script by:

Rscript foo.R --cutoff 0.01 --input file=foo.txt --verbose
Rscript foo.R -i file=foo.txt -v
Rscript foo.R -i file=foo.txt --no-verbose

Help message can be automatically generated:

> Rscript test_list.R --help
Usage: Rscript foo.R [options]

  --cutoff numeric
    cutoff of something (default is 0.05)

  --input { name=character, ... }
    input file

    print messages

    Print help message and exit

    Print version information and exit

Also, arguments can be set when calling GetoptLong:::source(), so it would be convinient to control variables even you are in an interactive R session:

GetoptLong:::source("foo.R", argv = "--cutoff 0.01 --input file=foo.txt --verbose")

Variable interpolation

This package also supports simple variable interpolation in R, 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.


GPL (>= 2)

jokergoo/GetoptLong documentation built on June 9, 2018, 6:24 p.m.