README
argparser
is a cross-platform command-line argument parser for R, written in R,
with no external dependencies. This package is useful with the Rscript
front-end and facilitates turning an R script into an executable script.
History
v0.6
Incompatability: values of numeric and integer arguments are now
checked for validity due to feature request (issue #16)
v0.5.1
- Negative numbers can now be parsed correctly as argument values
- Help message printing is prettier
- Concatenated short-form flags are now split into individual flags
v0.4 Simplify argument names
Incompatibility: -
in argument names are substitute by _
v0.3 Added support for multi-valued arguments
v0.2 Function names change
Incompatibility: .
in function names are replaced with _
v0.1 Initial release
Dependencies
- R (>= 3.0)
- roxygen2 (>= 4.0, for building only)
Build
Clone the repository, build the documentation with roxygen2, then install.
$ git clone https://bitbucket.org/djhshih/argparser.git $ cd argparser $ R R> library(roxygen2) R> roxygenize() R> quit() $ R CMD INSTALL .
Usage
Create a R script (e.g. round.R
) with a shebang line (Linux only).
Import the argparser library, create a parser, populate the parser with arguments and parse the command line arguments.
#!/usr/bin/env Rscript library(argparser, quietly=TRUE) # Create a parser p <- arg_parser("Round a floating point number") # Add command line arguments p <- add_argument(p, "number", help="number to round", type="numeric") p <- add_argument(p, "--digits", help="number of decimal places", default=0) # Parse the command line arguments argv <- parse_args(p) # Do work based on the passed arguments cat( round(argv$number, argv$digits), "\n")
Then, set the R script as executable and execute (Linux only).
$ chmod +x round.R
# Print the help message
$ ./round.R -h
Alternatively, run the script using Rscript (Linux or Windows).
$ Rscript round.R 3.141 # 3 $ Rscript round.R 3.141 -d 2 # 3.14
For R help, see ?argparser
.