module cli type FnCommandCallback = fn (cmd Command) ? // str returns the `string` representation of the callback. pub fn (f FnCommandCallback) str() string { return 'FnCommandCallback=>' + ptr_str(f) } // Command is a structured representation of a single command // or chain of commands. pub struct Command { pub mut: name string usage string description string version string pre_execute FnCommandCallback execute FnCommandCallback post_execute FnCommandCallback disable_help bool disable_version bool disable_flags bool sort_flags bool = true sort_commands bool = true parent &Command = 0 commands []Command flags []Flag required_args int args []string } // str returns the `string` representation of the `Command`. pub fn (cmd Command) str() string { mut res := []string{} res << 'Command{' res << ' name: "$cmd.name"' res << ' usage: "$cmd.usage"' res << ' version: "$cmd.version"' res << ' description: "$cmd.description"' res << ' disable_help: $cmd.disable_help' res << ' disable_flags: $cmd.disable_flags' res << ' disable_version: $cmd.disable_version' res << ' sort_flags: $cmd.sort_flags' res << ' sort_commands: $cmd.sort_commands' res << ' cb execute: $cmd.execute' res << ' cb pre_execute: $cmd.pre_execute' res << ' cb post_execute: $cmd.post_execute' if cmd.parent == 0 { res << ' parent: &Command(0)' } else { res << ' parent: &Command{$cmd.parent.name ...}' } res << ' commands: $cmd.commands' res << ' flags: $cmd.flags' res << ' required_args: $cmd.required_args' res << ' args: $cmd.args' res << '}' return res.join('\n') } // is_root returns `true` if this `Command` has no parents. pub fn (cmd Command) is_root() bool { return isnil(cmd.parent) } // root returns the root `Command` of the command chain. pub fn (cmd Command) root() Command { if cmd.is_root() { return cmd } return cmd.parent.root() } // full_name returns the full `string` representation of all commands int the chain. pub fn (cmd Command) full_name() string { if cmd.is_root() { return cmd.name } return cmd.parent.full_name() + ' $cmd.name' } // add_commands adds the `commands` array of `Command`s as sub-commands. pub fn (mut cmd Command) add_commands(commands []Command) { for command in commands { cmd.add_command(command) } } // add_command adds `command` as a sub-command of this `Command`. pub fn (mut cmd Command) add_command(command Command) { mut subcmd := command if cmd.commands.contains(subcmd.name) { println('Command with the name `$subcmd.name` already exists') exit(1) } subcmd.parent = cmd cmd.commands << subcmd } // setup ensures that all sub-commands of this `Command` // is linked as a chain. pub fn (mut cmd Command) setup() { for mut subcmd in cmd.commands { subcmd.parent = cmd subcmd.setup() } } // add_flags adds the array `flags` to this `Command`. pub fn (mut cmd Command) add_flags(flags []Flag) { for flag in flags { cmd.add_flag(flag) } } // add_flag adds `flag` to this `Command`. pub fn (mut cmd Command) add_flag(flag Flag) { if cmd.flags.contains(flag.name) { println('Flag with the name `$flag.name` already exists') exit(1) } cmd.flags << flag } // parse parses `args` into this structured `Command`. pub fn (mut cmd Command) parse(args []string) { if !cmd.disable_flags { cmd.add_default_flags() } cmd.add_default_commands() if cmd.sort_flags { cmd.flags.sort(a.name < b.name) } if cmd.sort_commands { cmd.commands.sort(a.name < b.name) } cmd.args = args[1..] if !cmd.disable_flags { cmd.parse_flags() } cmd.parse_commands() } // add_default_flags adds the commonly used `-h`/`--help` and // `-v`/`--version` flags to the `Command`. fn (mut cmd Command) add_default_flags() { if !cmd.disable_help && !cmd.flags.contains('help') { use_help_abbrev := !cmd.flags.contains('h') && cmd.flags.have_abbrev() cmd.add_flag(help_flag(use_help_abbrev)) } if !cmd.disable_version && cmd.version != '' && !cmd.flags.contains('version') { use_version_abbrev := !cmd.flags.contains('v') && cmd.flags.have_abbrev() cmd.add_flag(version_flag(use_version_abbrev)) } } // add_default_commands adds the command functions of the // commonly used `help` and `version` flags to the `Command`. fn (mut cmd Command) add_default_commands() { if !cmd.disable_help && !cmd.commands.contains('help') && cmd.is_root() { cmd.add_command(help_cmd()) } if !cmd.disable_version && cmd.version != '' && !cmd.commands.contains('version') { cmd.add_command(version_cmd()) } } fn (mut cmd Command) parse_flags() { for { if cmd.args.len < 1 || !cmd.args[0].starts_with('-') { break } mut found := false for i in 0 .. cmd.flags.len { unsafe { mut flag := &cmd.flags[i] if flag.matches(cmd.args, cmd.flags.have_abbrev()) { found = true flag.found = true cmd.args = flag.parse(cmd.args, cmd.flags.have_abbrev()) or { println('Failed to parse flag `${cmd.args[0]}`: $err') exit(1) } break } } } if !found { println('Command `$cmd.name` has no flag `${cmd.args[0]}`') exit(1) } } } fn (mut cmd Command) parse_commands() { global_flags := cmd.flags.filter(it.global) cmd.check_help_flag() cmd.check_version_flag() for i in 0 .. cmd.args.len { arg := cmd.args[i] for j in 0 .. cmd.commands.len { mut command := cmd.commands[j] if command.name == arg { for flag in global_flags { command.add_flag(flag) } command.parse(cmd.args[i..]) return } } } if cmd.is_root() && isnil(cmd.execute) { if !cmd.disable_help { cmd.execute_help() return } } // if no further command was found, execute current command if cmd.required_args > 0 { if cmd.required_args > cmd.args.len { eprintln('Command `$cmd.name` needs at least $cmd.required_args arguments') exit(1) } } cmd.check_required_flags() if !isnil(cmd.pre_execute) { cmd.pre_execute(*cmd) or { eprintln('cli preexecution error: $err') exit(1) } } if !isnil(cmd.execute) { cmd.execute(*cmd) or { eprintln('cli execution error: $err') exit(1) } } if !isnil(cmd.post_execute) { cmd.post_execute(*cmd) or { eprintln('cli postexecution error: $err') exit(1) } } } fn (cmd Command) check_help_flag() { if !cmd.disable_help && cmd.flags.contains('help') { help_flag := cmd.flags.get_bool('help') or { return } // ignore error and handle command normally if help_flag { cmd.execute_help() exit(0) } } } fn (cmd Command) check_version_flag() { if !cmd.disable_version && cmd.version != '' && cmd.flags.contains('version') { version_flag := cmd.flags.get_bool('version') or { return } // ignore error and handle command normally if version_flag { version_cmd := cmd.commands.get('version') or { return } // ignore error and handle command normally version_cmd.execute(version_cmd) or { panic(err) } exit(0) } } } fn (cmd Command) check_required_flags() { for flag in cmd.flags { if flag.required && flag.value.len == 0 { full_name := cmd.full_name() println('Flag `$flag.name` is required by `$full_name`') exit(1) } } } // execute_help executes the callback registered // for the `-h`/`--help` flag option. pub fn (cmd Command) execute_help() { if cmd.commands.contains('help') { help_cmd := cmd.commands.get('help') or { return } // ignore error and handle command normally help_cmd.execute(help_cmd) or { panic(err) } } else { print(cmd.help_message()) } } fn (cmds []Command) get(name string) ?Command { for cmd in cmds { if cmd.name == name { return cmd } } return error('Command `$name` not found in $cmds') } fn (cmds []Command) contains(name string) bool { for cmd in cmds { if cmd.name == name { return true } } return false }