parse_args {W4MRUtils}

Parse Command arguments

Description

parse_args Replacement for the parseCommandArgs utility from batch. Note that inputs like ⁠script.R some-list c(1, 2, 3)⁠ will result in args$some-list to be the string "c(1, 2, 3)", and not a vector anymore as this ability was permitted by dangerous behaviours from the batch package (the usage of eval which MUST NEVER be used on user's inputs).

To get a list of numeric from users, instead of using the c(1, 2) trick, please, use regular lists parsing:

> args$`some-list`
[1] "1,2"
args$`some-list` <- as.numeric(strsplit(args$`some-list`, ",")[[1]])
> args$`some-list`
[1] 1 2

Usage

parse_args(
  args = NULL,
  convert_booleans = TRUE,
  convert_numerics = TRUE,
  strip_trailing_dash = TRUE,
  replace_dashes = TRUE
)

Arguments

args

optional, provide arguments to parse. This function will use 'commandArgs()' if args is not provided

convert_booleans

logical - tells the function to convert values into logical if their value is "TRUE" or "FALSE".

convert_numerics

logical - tells the function to convert values into numeric if possible.

strip_trailing_dash

• tells whether to remove trailing hyphens from the start of the parameter name

replace_dashes

• tells whether to turn trailing hyphens into underscores

Value

a named list object containing the input parameters in values and the parameters names in names

Author(s)

L.Pavot

Examples

## faking command line parameters:

commandArgs <- function() {
  list(
    "--args",
    "param1", "a value",
    "param2", "42"
  )
}

## extracting command line parameters:
parameters <- W4MRUtils::parse_args(args = commandArgs())
str(parameters)