update mobi convert section

README.md

@@ -98,12 +98,20 @@ Options:
 
 ## Reading mobi files
 
-`epuppy`   doesn't   support  mobi   files,   but   you  can   install
-[mobitool](https://github.com/bfabiszewski/libmobi/)  and  use  it  to
-convert mobi files to epub. The ubuntu package is `libmobi-tools`. To convert, execute: 
+`epuppy`   doesn't   support  mobi   files,   but   you  can easily
+convert them to epub format using calibre, which contains a tool named
+`ebook-convert`. You can install it on Ubuntu with:
+
+`apt install calibre`
+
+On Fedora use:
+
+`dnf install ebook-tools`
+
+To convert, execute: 
 
 ```default
-mobitool -e somebook.epub
+ebook-convert somebook.mobi somebook.epub
 ```
 
 ## Installation

cmd/io.go

@@ -1,52 +0,0 @@
-/*
-Copyright © 2026 Thomas von Dein
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program. If not, see <http://www.gnu.org/licenses/>.
-*/
-package cmd
-
-import (
-	"fmt"
-	"log"
-	"os"
-)
-
-func FileExists(filename string) bool {
-	info, err := os.Stat(filename)
-
-	if err != nil {
-		// return false on any error
-		return false
-	}
-
-	return !info.IsDir()
-}
-
-func WriteFile(filename string, content []byte) error {
-	var err error
-
-	fd, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
-	if err != nil {
-		return fmt.Errorf("failed to open file %s for writing: %w", filename, err)
-	}
-	defer func() {
-		if err := fd.Close(); err != nil {
-			log.Fatal(err)
-		}
-	}()
-
-	_, err = fd.Write(content)
-
-	return err
-}

cmd/store.go

@@ -107,3 +107,32 @@ func Slug(input string) string {
 	slug = suffix.ReplaceAllString(slug, "")
 	return nonprintable.ReplaceAllString(slug, "")
 }
+
+func FileExists(filename string) bool {
+	info, err := os.Stat(filename)
+
+	if err != nil {
+		// return false on any error
+		return false
+	}
+
+	return !info.IsDir()
+}
+
+func WriteFile(filename string, content []byte) error {
+	var err error
+
+	fd, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
+	if err != nil {
+		return fmt.Errorf("failed to open file %s for writing: %w", filename, err)
+	}
+	defer func() {
+		if err := fd.Close(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	_, err = fd.Write(content)
+
+	return err
+}