feat(comma): Added help method.

src/comma.zig

@@ -1,6 +1,6 @@
 //! By convention, root.zig is the root source file when making a package.
 const std = @import("std");
-// const Io = std.Io;
+const Io = std.Io;
 
 pub const Command = struct {
     name: []const u8,
@@ -8,7 +8,10 @@ pub const Command = struct {
     long: ?[]const u8 = null,
     subcommands: []const Command = &.{},
     examples: [][]const u8 = &.{},
+    /// The enum type of the command
     Type: type,
+    /// The type of struct that holds the Commands's flags and arguments
+    // Params: type,
 
     pub fn new(cmd: CommandOptions) Command {
         const subcommands: [cmd.subcommands.len]Command = blk: {
@@ -43,6 +46,65 @@ pub const Command = struct {
 
         return @enumFromInt(self.subcommands.len + 1);
     }
+
+    /// Used for indentation when printing command help
+    const tab = "  ";
+
+    /// Print usage information to the console.
+    pub fn help(self: @This(), w: *Io.Writer) !void {
+        defer w.flush() catch {};
+
+        if (self.long) |long| {
+            try w.print("{s}\n\n", .{long});
+        }
+
+        try w.print("Usage:\n{s}{s}\n", .{ tab, self.name });
+
+        if (self.subcommands.len > 0) {
+            try w.print("\nAvailable Commands:\n", .{});
+
+            var max_width: u8 = 0;
+
+            inline for (self.subcommands) |cmd| {
+                max_width = @max(max_width, cmd.name.len);
+            }
+
+            // Print short command description
+            inline for (self.subcommands) |cmd| {
+                try w.print(
+                    "{s}{s}",
+                    .{
+                        tab,
+                        cmd.name,
+                    },
+                );
+
+                for (0..(max_width - cmd.name.len)) |_| {
+                    try w.print(" ", .{});
+                }
+
+                try w.print(
+                    " {s}\n",
+                    .{
+                        cmd.short orelse "",
+                    },
+                );
+            }
+
+            try w.print("\n", .{});
+        }
+
+        // TODO: Print flags
+
+        // TODO: Print arguments
+
+        if (self.subcommands.len > 0) {
+            try w.print(
+                "Use \"{s} [command] --help\" for more information about a command.",
+                .{self.name},
+            );
+        }
+    }
 };
 
 pub const ParseError = error{
@@ -78,3 +140,7 @@ const CommandOptions = struct {
         );
     }
 };
+
+// /// parses the args into params
+// pub fn params(cmd: Command, args: [][]const u8) cmd.Params {
+// }

src/main.zig

@@ -26,8 +26,12 @@ fn run(
 ) !void {
     const cmd = envr.root.parse(args[1..]);
     switch (cmd) {
-        .envr, .unknown => {
+        .envr => {
-            return fallback_to_go(io, arena, args);
+            var stdout_buffer: [4096]u8 = undefined;
+            var stdout_file_writer: Io.File.Writer = .init(.stdout(), io, &stdout_buffer);
+            const stdout_writer = &stdout_file_writer.interface;
+
+            return envr.root.help(stdout_writer);
         },
         .version => {
             var stdout_buffer: [1024]u8 = undefined;
@@ -47,6 +51,9 @@ fn run(
                 environ_map.get("PATH").?,
             );
         },
+        .unknown => {
+            return fallback_to_go(io, arena, args);
+        },
     }
 }
 

src/root.zig

@@ -7,6 +7,38 @@ const Command = comma.Command;
 
 pub const root: Command = .new(.{
     .name = "envr",
+    .short = "Manage your .env files.",
+    .long =
+    \\envr keeps your .env synced to a local, age encrypted database.
+    \\It is a safe and eay way to gather all your .env files in one place where they can
+    \\easily be backed by another tool such as restic or git.
+    \\All your data is stored in ~/data.age
+    \\
+    \\Getting started is easy:
+    \\
+    \\1. Create your configuration file and set up encrypted storage:
+    \\
+    \\> envr init
+    \\
+    \\2. Scan for existing .env files:
+    \\
+    \\> envr scan
+    \\
+    \\Select the files you want to back up from the interactive list.
+    \\
+    \\3. Verify that it worked:
+    \\
+    \\> envr list
+    \\
+    \\4. After changing any of your .env files, update the backup with:
+    \\
+    \\> envr sync
+    \\
+    \\5. If you lose a repository, after re-cloning the repo into the same path it was
+    \\at before, restore your backup with:
+    \\
+    \\> envr restore <path to repository> .env
+    ,
     .subcommands = &.{
         .{
             .name = "deps",
@@ -17,7 +49,10 @@ pub const root: Command = .new(.{
             \\ The deps command reports which binaries are available and which are not."
             ,
         },
-        .{ .name = "version" },
+        .{
+            .name = "version",
+            .short = "Show envr's version",
+        },
     },
 });
 
@@ -35,7 +70,7 @@ test "parse version" {
 }
 
 test "parse unknown" {
-    const args = &[_][]const u8{"bad", "value"};
+    const args = &[_][]const u8{ "bad", "value" };
     const cmd = root.parse(args);
 
     try std.testing.expectEqual(.unknown, cmd);