Add help flag to Zig main

Changes

4 changed files (+159/-56)

• src/RunOptions.zig (new)
  • @@ -0,0 +1,74 @@
    + // Copyright (C) 2025 Shota FUJI + // + // This program is free software: you can redistribute it and/or modify + // it under the terms of the GNU General Public License as published by + // the Free Software Foundation, either version 3 of the License, or + // (at your option) any later version. + // + // This program is distributed in the hope that it will be useful, + // but WITHOUT ANY WARRANTY; without even the implied warranty of + // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + // GNU General Public License for more details. + // + // You should have received a copy of the GNU General Public License + // along with this program. If not, see <https://www.gnu.org/licenses/>. + // + // SPDX-License-Identifier: GPL-3.0-only + + const c = @cImport({ + @cInclude("time.h"); + @cInclude("sunriset.h"); + }); + + latitude: f64 = c.DEFAULT_LATITUDE, + longitude: f64 = c.DEFAULT_LONGITUDE, + offset_hour: f64 = 0, + twilight_angle: f64 = c.TWILIGHT_ANGLE_DAYLIGHT, + now: c.time_t = 0, + target_time: c.time_t = 0, + now_delta: c_ulong = 0, + target_delta: c_ulong = 0, + function_report: c.OnOff = c.ONOFF_OFF, + function_list: c.OnOff = c.ONOFF_OFF, + function_poll: c.OnOff = c.ONOFF_OFF, + function_wait: c.OnOff = c.ONOFF_OFF, + utc: c.OnOff = c.ONOFF_OFF, + debug: c.OnOff = c.ONOFF_OFF, + report_sunrise: c.OnOff = c.ONOFF_OFF, + report_sunset: c.OnOff = c.ONOFF_OFF, + list_days: c_uint = c.DEFAULT_LIST, + utc_bias_hours: f64 = 0, + + pub fn init() @This() { + var opts = @This(){}; + + _ = c.time(&opts.now); + opts.now_delta = c.daysSince2000(&opts.now); + + return opts; + } + + pub fn toC(self: *const @This()) c.runStruct { + return c.runStruct{ + .latitude = self.latitude, + .longitude = self.longitude, + .offsetHour = self.offset_hour, + .twilightAngle = self.twilight_angle, + .nowTimet = self.now, + .targetTimet = self.target_time, + .now2000 = self.now_delta, + .target2000 = self.target_delta, + .functionVersion = c.ONOFF_OFF, + .functionUsage = c.ONOFF_OFF, + .functionReport = self.function_report, + .functionList = self.function_list, + .functionPoll = self.function_poll, + .functionWait = self.function_wait, + .utc = self.utc, + .debug = self.debug, + .reportSunrise = self.report_sunrise, + .reportSunset = self.report_sunset, + .listDays = self.list_days, + .utcBiasHours = self.utc_bias_hours, + }; + }
• src/main.zig
  • @@ -18,6 +18,8 @@
    const std = @import("std"); const config = @import("config"); + const RunOptions = @import("./RunOptions.zig"); + const c = @cImport({ @cInclude("time.h"); @cInclude("sunriset.h");
  • @@ -36,61 +38,41 @@ return @intFromEnum(self);
    } }; - const RunOptions = struct { - latitude: f64 = c.DEFAULT_LATITUDE, - longitude: f64 = c.DEFAULT_LONGITUDE, - offset_hour: f64 = 0, - twilight_angle: f64 = c.TWILIGHT_ANGLE_DAYLIGHT, - now: c.time_t = 0, - target_time: c.time_t = 0, - now_delta: c_ulong = 0, - target_delta: c_ulong = 0, - function_usage: c.OnOff = c.ONOFF_OFF, - function_report: c.OnOff = c.ONOFF_OFF, - function_list: c.OnOff = c.ONOFF_OFF, - function_poll: c.OnOff = c.ONOFF_OFF, - function_wait: c.OnOff = c.ONOFF_OFF, - utc: c.OnOff = c.ONOFF_OFF, - debug: c.OnOff = c.ONOFF_OFF, - report_sunrise: c.OnOff = c.ONOFF_OFF, - report_sunset: c.OnOff = c.ONOFF_OFF, - list_days: c_uint = c.DEFAULT_LIST, - utc_bias_hours: f64 = 0, - - pub fn init() @This() { - var opts = RunOptions{}; - - _ = c.time(&opts.now); - opts.now_delta = c.daysSince2000(&opts.now); - - return opts; - } - - pub fn toC(self: *const RunOptions) c.runStruct { - return c.runStruct{ - .latitude = self.latitude, - .longitude = self.longitude, - .offsetHour = self.offset_hour, - .twilightAngle = self.twilight_angle, - .nowTimet = self.now, - .targetTimet = self.target_time, - .now2000 = self.now_delta, - .target2000 = self.target_delta, - .functionVersion = c.ONOFF_OFF, - .functionUsage = self.function_usage, - .functionReport = self.function_report, - .functionList = self.function_list, - .functionPoll = self.function_poll, - .functionWait = self.function_wait, - .utc = self.utc, - .debug = self.debug, - .reportSunrise = self.report_sunrise, - .reportSunset = self.report_sunset, - .listDays = self.list_days, - .utcBiasHours = self.utc_bias_hours, - }; - } - }; + fn writeHelp(writer: anytype, bin: []const u8) !void { + try std.fmt.format(writer, + \\[Usage] + \\{s} [options...] <command> [parameters...] + \\ + \\[Options] + \\-v, --version Prints version to stdout and exits. + \\-h, --help Prints this message to stdout and exits. + \\ + \\[Commands] + \\poll Prints whether it's DAY or NIGHT. + \\wait Sleep until sunrise and/or sunset, then exits. + \\report Prints sunrise and sunset times. + \\list List sunrise and sunset times for next <DAYS>. + \\ + \\[Common Parameters] + \\TWILIGHT Twilight type. Valid values are: + \\ * daylight + \\ * civil + \\ * nautical + \\ * astronomical + \\ * angle <degree> + \\EVENT TYPE Use "rise" for sunrise and "set" for sunset. + \\ If this parameter is not set, sunwait targets both. + \\OFFSET Time offset for sunrise and sunset time, towards noon. + \\ Format must be "MM" (minutes) or "HH:MM". + \\LATITUDE Angle in degree, positive floating point number. + \\ Must have N or S suffix. + \\LONGITUDE Angle in degree, positive floating point number. + \\ Must have E or W suffix. + \\ + \\See man page for "sunwait(1)" for more. + \\ + , .{bin}); + } pub fn main() u8 { var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
  • @@ -106,11 +88,24 @@ return ExitCode.out_of_memory.code();
    }; defer args.deinit(); - _ = args.skip(); + const bin_name = args.next() orelse { + std.log.err("Got no arguments, exiting.", .{}); + return ExitCode.generic_error.code(); + }; + while (args.next()) |arg| { if (std.mem.eql(u8, "-v", arg) or std.mem.eql(u8, "--version", arg)) { std.fmt.format(std.io.getStdOut().writer(), "{s}\n", .{config.version}) catch |err| { std.log.err("Unable to write to stdout: {s}", .{@errorName(err)}); + return ExitCode.stdout_write_error.code(); + }; + + return ExitCode.ok.code(); + } + + if (std.mem.eql(u8, "-h", arg) or std.mem.eql(u8, "--help", arg)) { + writeHelp(std.io.getStdOut().writer(), bin_name) catch |err| { + std.log.err("Unable to write help message to stdout: {s}", .{@errorName(err)}); return ExitCode.stdout_write_error.code(); };
• tests/help.zig (new)
  • @@ -0,0 +1,33 @@
    + // Copyright (C) 2025 Shota FUJI + // + // This program is free software: you can redistribute it and/or modify + // it under the terms of the GNU General Public License as published by + // the Free Software Foundation, either version 3 of the License, or + // (at your option) any later version. + // + // This program is distributed in the hope that it will be useful, + // but WITHOUT ANY WARRANTY; without even the implied warranty of + // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + // GNU General Public License for more details. + // + // You should have received a copy of the GNU General Public License + // along with this program. If not, see <https://www.gnu.org/licenses/>. + // + // SPDX-License-Identifier: GPL-3.0-only + + const std = @import("std"); + + const config = @import("config"); + + test { + const result = try std.process.Child.run(.{ + .allocator = std.testing.allocator, + .argv = &.{ config.new_bin, "--help" }, + }); + defer std.testing.allocator.free(result.stderr); + defer std.testing.allocator.free(result.stdout); + + try std.testing.expectEqual(0, result.term.Exited); + try std.testing.expectEqual(0, result.stderr.len); + try std.testing.expect(result.stdout.len > 0); + }
• tests/main.zig
  • @@ -18,5 +18,6 @@
    comptime { _ = @import("./report.zig"); _ = @import("./poll.zig"); + _ = @import("./help.zig"); _ = @import("./version.zig"); }