commandArgs: Extract Command Line Arguments

Description

Provides access to a copy of the command line arguments supplied when this Rsession was invoked. This function is backward compatible with commandArgs() of the base package, but adds more features.

Usage

commandArgs(asValues=FALSE, excludeReserved=FALSE, excludeEnvVars=FALSE, os=NULL, ...)

Arguments

asValues

If TRUE, a named list is returned, where command line arguments of type --foo will be returned as

excludeReserved

If TRUE, arguments reserved by Rare excluded, otherwise not. Which the reserved arguments are depends on operating system. For details, see Appendix B on "Invoking R" in An Intro

excludeEnvVars

If TRUE, arguments that assigns environment variable are excluded, otherwise not. As described in R --help, these are arguments of format =.

A vector of character strings specifying which set of reserved arguments to be used. Possible values are "unix", "mac

...

Passed to commandArgs() of the base package.

Value

Returns a character vector containing the names of the executable and the user-supplied command line arguments, or a list if asValue is TRUE. The first element is the name of the executable by which Rwas invoked. As far as I am aware, the exact form of this element is platform dependent. It may be the fully qualified name, or simply the last component (or basename) of the application. The attribute isReserved is a logical vector specifying if the corresponding command line argument is a reserved Rargument or not.

Details

This function should be fully backward compatible with the same function in the base package.

Examples

Run this code

# Get all arguments
  commandArgs()

  ## Spawn a copy of this application as it was invoked.
  ## system(paste(commandArgs(), collapse=" "))

  # Get only "private" arguments and not the name of the R executable.
  commandArgs(excludeReserved=TRUE)[-1]

  # If R is started as
  #   R DATAPATH=../data --args --root="do da" --foo bar --details --a=2
  # then commandArgs(asValue=TRUE) returns a list like
  #   list(R=NA, DATAPATH="../data" args=TRUE, root="do da", foo="bar", details=TRUE, a="2")

Run the code above in your browser using DataLab

Last chance! 50% off unlimited learning