Adapt to LESS_TERMCAP_md and LESS_TERMCAP_us

Fixes #14

m/ansiTokenizer.go

@@ -3,6 +3,7 @@ package m
 import (
 	"fmt"
 	"log"
+	"os"
 	"regexp"
 	"strconv"
 	"strings"
@@ -21,6 +22,28 @@ type Token struct {
 	Style tcell.Style
 }
 
+// SetManPageFormatFromEnv parses LESS_TERMCAP_xx environment variables and
+// adapts the moar output accordingly.
+func SetManPageFormatFromEnv(logger *log.Logger) {
+	// Requested here: https://github.com/walles/moar/issues/14
+
+	lessTermcapMd := os.Getenv("LESS_TERMCAP_md")
+	if lessTermcapMd != "" {
+		manPageBold = _TermcapToStyle(logger, lessTermcapMd)
+	}
+
+	lessTermcapUs := os.Getenv("LESS_TERMCAP_us")
+	if lessTermcapUs != "" {
+		manPageUnderline = _TermcapToStyle(logger, lessTermcapUs)
+	}
+}
+
+func _TermcapToStyle(logger *log.Logger, termcap string) tcell.Style {
+	// Add a character to be sure we have one to take the format from
+	tokens, _ := TokensFromString(logger, termcap+"x")
+	return tokens[len(tokens)-1].Style
+}
+
 // TokensFromString turns a (formatted) string into a series of tokens,
 // and an unformatted string
 func TokensFromString(logger *log.Logger, s string) ([]Token, *string) {

m/pager.go

@@ -576,6 +576,8 @@ func (p *Pager) StartPaging(logger *log.Logger, screen tcell.Screen) {
 	// We want to match the terminal theme, see screen.Init() source code
 	os.Setenv("TCELL_TRUECOLOR", "disable")
 
+	SetManPageFormatFromEnv(logger)
+
 	if e := screen.Init(); e != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", e)
 		os.Exit(1)