Add support for MarkDown headings formatted as "COMMAND(1) ..."

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

md2man/roff.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"regexp"
 	"strings"
 
 	"github.com/russross/blackfriday/v2"
@@ -163,12 +164,11 @@ func (r *roffRenderer) RenderNode(w io.Writer, node *blackfriday.Node, entering
 	return walkAction
 }
 
+var title = regexp.MustCompile(`^(\s*\w+)\((\d)\)`)
 func (r *roffRenderer) handleText(w io.Writer, node *blackfriday.Node, entering bool) {
-	var (
-		start, end string
-	)
 	// handle special roff table cell text encapsulation
 	if node.Parent.Type == blackfriday.TableCell {
+		var start, end string
 		if len(node.Literal) > 30 {
 			start = tableCellStart
 			end = tableCellEnd
@@ -178,10 +178,19 @@ func (r *roffRenderer) handleText(w io.Writer, node *blackfriday.Node, entering
 				end = crTag
 			}
 		}
+		out(w, start)
+		escapeSpecialChars(w, node.Literal)
+		out(w, end)
+		return
+	}
+	literal := node.Literal
+	if r.firstHeader && title.Match(node.Literal){
+		if r.firstHeader && title.Match(literal){
+			// "COMMAND(1) SOMETHING" => "COMMAND 1 SOMETHING"
+			literal = title.ReplaceAll(literal, []byte("${1} ${2}"))
+		}
 	}
-	out(w, start)
-	escapeSpecialChars(w, node.Literal)
-	out(w, end)
+	escapeSpecialChars(w, literal)
 }
 
 func (r *roffRenderer) handleHeading(w io.Writer, node *blackfriday.Node, entering bool) {

md2man/roff_test.go

@@ -10,6 +10,21 @@ type TestParams struct {
 	extensions blackfriday.Extensions
 }
 
+func TestFirstHeading(t *testing.T) {
+	var tests = []string{
+		`DOCKER 1 "JUNE 2014" "Docker Community" "Docker User Manuals"
+====
+`,
+		`.nh
+.TH DOCKER 1 "JUNE 2014" "Docker Community" "Docker User Manuals"`,
+
+		`#   DOCKER(1) "JUNE 2014" "Docker Community" "Docker User Manuals"`,
+		`.nh
+.TH DOCKER 1 "JUNE 2014" "Docker Community" "Docker User Manuals"`,
+	}
+	doTestsInline(t, tests)
+}
+
 func TestEmphasis(t *testing.T) {
 	var tests = []string{
 		"nothing inline\n",