commandArgs {R.utils}R Documentation

Extract Command Line Arguments

Description

Provides access to a copy of the command line arguments supplied when this R session 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 TRUE with name foo, and arguments of type -foo=value will be returned as character string value with name foo. In addition, if -foo value is given, this is interpreted as -foo=value, as long as value does not start with a double dash (--).
excludeReserved If TRUE, arguments reserved by R are excluded, otherwise not. Which the reserved arguments are depends on operating system. For details, see Appendix B on "Invoking R" in An Introduction to R.
excludeEnvVars If TRUE, arguments that assigns environment variable are excluded, otherwise not. As described in R --help, these are arguments of format <key>=<value>.
os A vector of character strings specifying which set of reserved arguments to be used. Possible values are "unix", "mac", "windows", "ANY" or "current". If "current", the current platform is used. If "ANY" or NULL, all three OSs are assumed for total cross-platform compatibility.
... Passed to commandArgs() of the base package.

Details

This function should be fully backward compatible with the same function in 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 R was 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 R argument or not.

Author(s)

Henrik Bengtsson (http://www.braju.com/R/)

See Also

commandArgs(), Platform()

Examples

  # 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")

[Package R.utils version 1.1.1 Index]