~sotirisp/kindleto

b36568228c12805450d40eb8bf61c5ac90e370e7 — Sotiris Papatheodorou 1 year, 11 months ago a5c5ed7
Filter escape characters from text

Didn't add an option to display them as suggested in
https://datatracker.ietf.org/doc/html/rfc1288#section-3.3
because they don't affect the Kindle's browser anyway.
2 files changed, 17 insertions(+), 1 deletions(-)

M text/text.go
M util/filter.go
M text/text.go => text/text.go +1 -0
@@ 37,6 37,7 @@ func TextToHTML(w http.ResponseWriter, u *url.URL, rd *bufio.Reader, td template
			fmt.Println(line)
		}
		line = util.StripSGR(line)
		line = util.StripEscapes(line)
		line = html.EscapeString(line)
		io.WriteString(w, line)
	}

M util/filter.go => util/filter.go +16 -1
@@ 1,10 1,11 @@
// SPDX-FileCopyrightText: 2020 Paul Gorman
// SPDX-FileCopyrightText: 2021 Sotiris Papatheodorou
// SPDX-FileCopyrightText: 2021-2022 Sotiris Papatheodorou
// SPDX-License-Identifier: GPL-3.0-or-later

package util

import (
	"bytes"
	"regexp"
)



@@ 15,3 16,17 @@ var sgrRegex = regexp.MustCompile(`\x1b\[([0-9]{1,3};)*[0-9]{0,3}m`)
func StripSGR(s string) string {
	return sgrRegex.ReplaceAllString(s, "")
}

// StripEscapes returns with all characters below ASCII 32 removed.
func StripEscapes(s string) string {
	// See the security recommendations from here:
	// https://datatracker.ietf.org/doc/html/rfc1288#section-3.3
	buf := bytes.Buffer{}
	for i := 0; i < len(s); i++ {
		b := s[i]
		if b == 9 || b == 10 || b == 13 || b >= 32 {
			buf.WriteByte(b)
		}
	}
	return buf.String()
}