module Arg: sig endThis module provides a general mechanism for extracting options and arguments from the command line to the program.
Syntax of command lines:
A keyword is a character string starting with a -.
An option is a keyword alone or followed by an argument.
The types of keywords are: Unit, Set, Clear, String,
Int, Float, and Rest. Unit, Set and Clear keywords take
no argument. String, Int, and Float keywords take the following
word on the command line as an argument. A Rest keyword takes the
remaining of the command line as (string) arguments.
Arguments not preceded by a keyword are called anonymous arguments.
Examples (cmd is assumed to be the command name):
cmd -flag (a unit option)cmd -int 1 (an int option with argument 1)cmd -string foobar (a string option with argument "foobar")cmd -float 12.34 (a float option with argument 12.34)cmd a b c (three anonymous arguments: "a", "b", and "c")cmd a b -- c d (two anonymous arguments and a rest option with
two arguments)type spec =
| |
Unit of |
(* | Call the function with unit argument | *) |
| |
Set of |
(* | Set the reference to true | *) |
| |
Clear of |
(* | Set the reference to false | *) |
| |
String of |
(* | Call the function with a string argument | *) |
| |
Int of |
(* | Call the function with an int argument | *) |
| |
Float of |
(* | Call the function with a float argument | *) |
| |
Rest of |
(* | Stop interpreting keywords and call the
function with each remaining argument | *) |
val parse : (string * spec * string) list -> (string -> unit) -> string -> unitArg.parse speclist anonfun usage_msg parses the command line.
speclist is a list of triples (key, spec, doc).
key is the option keyword, it must start with a '-' character.
spec gives the option type and the function to call when this option
is found on the command line.
doc is a one-line description of this option.
anonfun is called on anonymous arguments.
The functions in spec and anonfun are called in the same order
as their arguments appear on the command line.
If an error occurs, Arg.parse exits the program, after printing
an error message as follows:
usage_msgdoc string.-, include for example ("-", String anonfun, doc) in speclist.
By default, parse recognizes two unit options, -help and --help,
which will display usage_msg and the list of options, and exit
the program. You can override this behaviour by specifying your
own -help and --help options in speclist.
val parse_argv : string array ->
(string * spec * string) list -> (string -> unit) -> string -> unitArg.parse_argv args speclist anonfun usage_msg parses array args as
if it were the command line.exception Bad of string
spec or anonfun can raise Arg.Bad with an error
message to reject invalid arguments.val usage : (string * spec * string) list -> string -> unitArg.usage speclist usage_msg prints an error message including
the list of valid options. This is the same message that
Arg.parse prints in case of error.
speclist and usage_msg are the same as for Arg.parse.val current : int Pervasives.ref