improve args handling

src/main.zig

@@ -2,9 +2,6 @@ const std = @import("std");
 const clap = @import("clap");
 const md4c = @import("md4c_h.zig");
 const ansi = @import("ansi-term");
-const cstdio = @cImport({
-    @cInclude("stdio.h");
-});
 
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
@@ -12,7 +9,8 @@ pub fn main() !void {
 
     const params = comptime clap.parseParamsComptime(
         \\-h, --help display this help and exit
-        \\<FILE> file to read from, if empty or "-" use stdin.
+        \\-v, --version display the version and exit
+        \\<FILE> file to read from, empty or "-" use stdin
         \\
     );
 
@@ -30,8 +28,14 @@ pub fn main() !void {
     };
     defer res.deinit();
 
+    if (res.args.help != 0) return clap.help(std.io.getStdErr().writer(), clap.Help, &params, .{});
+
+    const version_string = "0.1.1\n";
+
+    if (res.args.version != 0) return std.debug.print(version_string, .{});
+
     var reader: std.io.AnyReader = undefined;
-    if (res.positionals.len < 1) {
+    if (res.positionals.len < 1 or std.mem.eql(u8, res.positionals[0], "-")) {
         reader = std.io.getStdIn().reader().any();
     } else {
         const filename = res.positionals[0];
@@ -97,30 +101,36 @@ const State = struct {
 };
 
 fn enter_block(blocktype: md4c.MD_BLOCKTYPE, detail: ?*anyopaque, userdata: ?*anyopaque) callconv(.C) c_int {
-    //std.debug.print("enter {d}\n", .{blocktype});
     const state: *State = @ptrCast(@alignCast(userdata));
 
     if (blocktype == md4c.MD_BLOCK_H) {
         just_write(state.writer, "\n");
+
         const h_detail: *md4c.MD_BLOCK_H_DETAIL = @ptrCast(@alignCast(detail));
+
         var temp_style = state.last_style;
         temp_style.font_style.dim = true;
         temp_style.font_style.bold = true;
         state.update_style(temp_style);
+
         for (0..h_detail.level) |_| {
             just_write(state.writer, "#");
         }
+
         temp_style.font_style.dim = false;
         temp_style.font_style.bold = state.nested_bold_count > 0;
         state.update_style(temp_style);
+
         just_write(state.writer, " ");
     }
     if (blocktype == md4c.MD_BLOCK_LI) {
         const li_detail: *md4c.MD_BLOCK_LI_DETAIL = @ptrCast(@alignCast(detail));
+
         var temp_style = state.last_style;
         if (li_detail.is_task == 0) temp_style.font_style.dim = true;
         temp_style.font_style.bold = true;
         state.update_style(temp_style);
+
         if (li_detail.is_task == 0) {
             just_write(state.writer, "• ");
         } else {
@@ -130,6 +140,7 @@ fn enter_block(blocktype: md4c.MD_BLOCKTYPE, detail: ?*anyopaque, userdata: ?*an
                 just_write(state.writer, "☐ ");
             }
         }
+
         temp_style.font_style.dim = false;
         temp_style.font_style.bold = state.nested_bold_count > 0;
         state.update_style(temp_style);
@@ -141,7 +152,6 @@ fn enter_block(blocktype: md4c.MD_BLOCKTYPE, detail: ?*anyopaque, userdata: ?*an
 }
 
 fn leave_block(blocktype: md4c.MD_BLOCKTYPE, detail: ?*anyopaque, userdata: ?*anyopaque) callconv(.C) c_int {
-    //std.debug.print("leave {d}\n", .{blocktype});
     const state: *State = @ptrCast(@alignCast(userdata));
 
     if (blocktype == md4c.MD_BLOCK_H) {
@@ -151,14 +161,15 @@ fn leave_block(blocktype: md4c.MD_BLOCKTYPE, detail: ?*anyopaque, userdata: ?*an
         just_write(state.writer, "\n");
     }
     if (blocktype == md4c.MD_BLOCK_HR) {
-        var winsize: std.c.winsize = undefined;
         var temp_style = state.last_style;
         temp_style.font_style.dim = true;
         temp_style.font_style.bold = true;
         state.update_style(temp_style);
-        const term_name_c = cstdio.ctermid(null);
-        const term_name = std.mem.sliceTo(term_name_c, 0);
+
+        const term_name = "/dev/tty";
         const term_fd = std.posix.open(term_name, .{}, 0) catch errorexit(5, "failed to open terminal D:\n");
+
+        var winsize: std.c.winsize = undefined;
         if (std.c.ioctl(term_fd, std.c.T.IOCGWINSZ, &winsize) != -1) {
             for (0..winsize.ws_col) |_| {
                 just_write(state.writer, "-");
@@ -167,6 +178,7 @@ fn leave_block(blocktype: md4c.MD_BLOCKTYPE, detail: ?*anyopaque, userdata: ?*an
         } else {
             just_write(state.writer, "---\n");
         }
+
         temp_style.font_style.dim = false;
         temp_style.font_style.bold = state.nested_bold_count > 0;
         state.update_style(temp_style);
@@ -201,14 +213,16 @@ fn enter_span(spantype: md4c.MD_SPANTYPE, detail: ?*anyopaque, userdata: ?*anyop
         temp_style.foreground = .Blue;
         temp_style.font_style.underline = true;
         state.update_style(temp_style);
-        just_write(state.writer, "\x1b]8;;");
+
+        just_write(state.writer, "\x1b]8;;"); // OSC 8 link begin
+
         const detail_a: *md4c.MD_SPAN_A_DETAIL = @ptrCast(@alignCast(detail));
         const link_c = detail_a.href.text;
         const link = link_c[0..detail_a.href.size];
+
         just_write(state.writer, link);
-        just_write(state.writer, "\x07");
+        just_write(state.writer, "\x07"); // OSC 8 link seperate url and text
     }
-    // TODO emit ansi to the writer
     return 0; // TODO what does the return value represent ????
 }
 
@@ -232,13 +246,13 @@ fn leave_span(spantype: md4c.MD_SPANTYPE, detail: ?*anyopaque, userdata: ?*anyop
         state.update_underline();
     }
     if (spantype == md4c.MD_SPAN_A) {
-        just_write(state.writer, "\x1b]8;;\x07");
+        just_write(state.writer, "\x1b]8;;\x07"); // OSC 8 link end
+
         var temp_style = state.last_style;
         temp_style.foreground = .Default;
         state.update_style(temp_style);
         state.update_underline();
     }
-    // TODO emit ansi to the writer
     return 0; // TODO what does the return value represent ????
 }
 
@@ -260,7 +274,9 @@ fn on_text(texttype: md4c.MD_TEXTTYPE, text: [*c]const md4c.MD_CHAR, size: md4c.
         var temp_style = state.last_style;
         temp_style.font_style.dim = true;
         state.update_style(temp_style);
+
         just_write(state.writer, text_data);
+
         temp_style.font_style.dim = false;
         state.update_style(temp_style);
     }
@@ -282,6 +298,7 @@ const parser: md4c.MD_PARSER = .{
 };
 
 fn errorexit(code: u8, comptime msg: []const u8) noreturn {
+    std.debug.print("mdcat exiting with error: ", .{});
     std.debug.print(msg, .{});
     std.process.exit(code);
 }