parse.args {reader}

Function to collect arguments when running R from the command line

Description

Allows parameter specification by A=..., B=... in the command line e.g, R < myScript.R M=1 NAME=John X=10.5, using commandArgs()

Usage

parse.args(arg.list = NULL, coms = c("X"), def = 0, list.out = F,
  verbose = TRUE)

Arguments

arg.list

the result of a commandArgs() call, or else NULL to initiate this call within the function

coms

list of valid commands to look for, not case sensitive

def

list of default values for each parameter (in same order)

list.out

logical, whether to return output as a list or data.frame

verbose

logical, whether to print to the console which assignments are made and warning messages

Value

returns dataframe showing the resulting values [column 1, "value"] for each 'coms' (rownames); or, if list.out=TRUE, then returns a list with names corresponding to 'coms' and values equivalent to 'value' column of the data.frame that would be returned if list.out=FALSE

Author(s)

Nicholas Cooper [e-mail]

Examples

parse.args(c("M=1","NAME=John","X=10.5"),coms=c("M","X","NAME"))
parse.args(c("N=1")) # invalid command entered, ignored with warning
temp.fn <- "tempScript1234.R"
# make a temporary R Script file to call using the command line
# not run # writeLines(c("require(reader)","parse.args(coms=c('M','X','NAME'))"),con=temp.fn)
bash.cmd <- "R --no-save < tempScript1234.R M=1 NAME=John X=10.5"
# run above command in the terminal, or using 'system' below:
# not run # arg <- system(bash.cmd)
# not run # unlink(temp.fn) # delete temporary file