getopt.md
In getopt: C-Like 'getopt' Behavior

getopt works as expected

Code
  cat(getopt(spec2, usage = TRUE))
Output
  Usage: NA [-[-date|d] <character>] [-[-help|h]] [-[-getdata|g]] [-[-market|m] <character>] [-[-threshold|t] <double>]

append collects repeated flag values into a vector

Code
  getopt(spec, "-p")
Condition
  Error in `getopt()`:
  ! flag `p` requires an argument

operand = 'strict' collects non-flag tokens as operands

Code
  getopt(spec, c("--unknown"), operand = "strict")
Condition
  Error in `get_rowmatch()`:
  ! long flag "unknown" is invalid

more helpful warnings upon incorrect input

Code
  spec <- matrix(c("count", "c", 1, "integer"), ncol = 4, byrow = TRUE)
  getopt(spec, c("-c", "hello"))$count
Condition
  Warning in `value[[3L]]()`:
  integer expected, got "hello"
Output
  [1] "hello"

Code
  spec <- NULL
  getopt(spec, "")
Condition
  Error in `as_spec()`:
  ! argument "spec" must be a matrix, data frame, or character vector with length divisible by 4.
Code
  spec <- c("foo", "f", 0)
  getopt(spec, "")
Condition
  Error in `as_spec()`:
  ! argument "spec" must be a matrix, data frame, or character vector with length divisible by 4.
Code
  spec <- matrix(c("foo", "f", 0, "integer"), ncol = 2)
  getopt(spec, "")
Condition
  Error in `as_spec()`:
  ! "spec" should have at least 4 columns.
Code
  spec <- matrix(c("foo", "f", 0, "integer", "bar", "b", 0, "integer"), ncol = 8)
  getopt(spec, "")
Condition
  Error in `as_spec()`:
  ! "spec" should have no more than 6 columns.
Code
  spec <- matrix(c("foo", "f", "store_sideways", "logical"), ncol = 4, byrow = TRUE)
  getopt(spec, "")
Condition
  Error in `as_spec()`:
  ! column 3 of "spec" contains invalid action(s): "store_sideways".  Valid actions: "append", "count", "store", "store_false", "store_optional", "store_true".
Code
  spec <- matrix(c("foo", "f", 0, "bignum"), ncol = 4, byrow = TRUE)
  getopt(spec, "")
Condition
  Error in `as_spec()`:
  ! column 4 of "spec" contains invalid mode(s): "bignum".  Valid modes: "character", "complex", "double", "integer", "logical".

Optional usage strings work as expected

Code
  cat(getopt(spec, usage = TRUE))
Output
  Usage: NA [-[-foo|f]] [-[-foobar|b] <character>] [-[-biz|z] [<logical>]] [-[-number|n] <double>] [-[-help|h]]
      -f|--foo       foo usage
      -b|--foobar    foobar usage
      -z|--biz       biz usage
      -n|--number    number usage
      -h|--help      help

debug output

Code
  . <- getopt(spec, c("--foo", "--bar", "baz"), debug = TRUE)
Output
  processing --foo 
    long option: --foo 
  processing --bar 
    long option: --bar 
        requires a argument
            peeking ahead at: 'baz' 
                consuming argument 'baz'

Code
  . <- getopt(spec, c("-fn", "2"), debug = TRUE)
Output
  normalized opt to: -f -n 2 
  processing -f 
    short option: -f 
  processing -n 
    short option: -n 
        optionally takes an argument
            peeking ahead at: '2' 
                consuming argument '2'

Code
  . <- getopt(spec, c("-b", "-"), debug = TRUE)
Output
  processing -b 
    short option: -b 
        requires a argument
            peeking ahead at: '-' 
                consuming argument '-'

Code
  . <- getopt(spec, c("--foo", "--", "file1.txt", "file2.txt"), debug = TRUE)
Output
  extracted positional args after `--`: file1.txt file2.txt 
  processing --foo 
    long option: --foo