Module CommandSource

Specifications for command-line auto-completion.

Argument types.

Command-line flag specifications.

Anonymous command-line argument specification.

Command-line parameter specification.

The old interface for command-line specifications -- Do Not Use.

Commands which can be combined into a hierarchy of subcommands.

basic_spec ~summary ?readme spec main is a basic command that executes a function main which is passed parameters parsed from the command line according to spec. summary is to contain a short one-line description of its behavior. readme is to contain any longer description of its behavior that will go on that command's help screen.

Same general behavior as basic_spec, but takes a command line specification built up using Params instead of Spec.

basic_or_error is like basic, except that the main function it expects may return an error, in which case it prints out the error message and shuts down with exit code 1.

group ~summary subcommand_alist is a compound command with named subcommands, as found in subcommand_alist. summary is to contain a short one-line description of the command group. readme is to contain any longer description of its behavior that will go on that command's help screen.

NOTE: subcommand names containing underscores will be rejected; use dashes instead.

body is called when no additional arguments are passed -- in particular, when no subcommand is passed. Its path argument is the subcommand path by which the group command was reached.

lazy_group is the same as group, except that the list of subcommands may be generated lazily.

exec ~summary ~path_to_exe runs exec on the executable at path_to_exe. If path_to_exe is `Absolute path then path is executed without any further qualification. If it is `Relative_to_me path then Filename.dirname Sys.executable_name ^ "/" ^ path is executed instead. All of the usual caveats about Sys.executable_name apply: specifically, it may only return an absolute path in Linux. On other operating systems it will return Sys.argv.(0). If it is `Relative_to_argv0 path then Sys.argv.(0) ^ "/" ^ path is executed.

The child_subcommand argument allows referencing a subcommand one or more levels below the top-level of the child executable. It should not be used to pass flags or anonymous arguments to the child.

Care has been taken to support nesting multiple executables built with Command. In particular, recursive help and autocompletion should work as expected.

NOTE: Non-Command executables can be used with this function but will still be executed when help -recursive is called or autocompletion is attempted (despite the fact that neither will be particularly helpful in this case). This means that if you have a shell script called "reboot-everything.sh" that takes no arguments and reboots everything no matter how it is called, you shouldn't use it with exec.

Additionally, no loop detection is attempted, so if you nest an executable within itself, help -recursive and autocompletion will hang forever (although actually running the subcommand will work).

of_lazy thunk constructs a lazy command that is forced only when necessary to run it or extract its shape.

Extracts the summary string for a command.

A Command_shape allows limited introspection of a Command, including subcommands, arguments, and doc strings. Think of it as machine-readable help.

call this instead of Core.exit if in command-related code that you want to run in tests. For example, in the body of Command.Param.no_arg_abort

Deprecated should be used only by Deprecated_command. At some point it will go away.

• deprecated [since 2021-03] Use [Command_unix]

• deprecated [since 2021-03] Use [Command_unix]