check return of ReadString()

Makefile

@@ -63,6 +63,7 @@ lint:
 
 lint-full:
 	golangci-lint run --enable-all --exclude-use-default --disable exhaustivestruct,exhaustruct,depguard,interfacer,deadcode,golint,structcheck,scopelint,varcheck,ifshort,maligned,nosnakecase,godot,funlen,gofumpt,cyclop,noctx,gochecknoglobals,paralleltest
+	gocritic check -enableAll *.go
 
 testfuzzy: clean
 	go test -fuzz ./... $(ARGS)

README-de.md

@@ -222,6 +222,49 @@ Sowie alle Bilder.
 Das Format kann man mit der Variable `template` in der Konfiguration
 ändern. Die `example.conf` enthält ein Beispiel für das Standard Template.
 
+## Verhalten des Tools
+
+Es gibt einige Dinge über das Verhalten von kleingebäck, über die Du
+Bescheid wissen solltest:
+
+- alle HTML Seiten und Bilder werden immer heruntergeladen
+- es wird ein (konfigurierbarer) Useragent verwendet
+- HTTP Cookies werden beachtet
+- bei Fehlern wird dreimal mit unterschiedlichem Abstand erneut
+  versucht
+- Bilder Downloads laufen parallelisiert mit leicht unterschiedlichen
+  zeitlichen Abständen ab
+- Gleich aussehende Bilder werden nicht überschrieben
+
+Der letzte Punkt muss genauer erläutert werden:
+
+Wenn man bei Kleinanzeigen.de eine Anzeige einstellt und Bilder
+postet, werden diese dort in ihrer Grösse reduziert (durch Kompression
+und Verkleinerung der Bilder usw.). Diese reduzierten Bilder werden
+dann von kleingebäck heruntergeladen. Falls Du Deine original Bilder
+behalten hast, kannst Du diese danach in das Backupverzeichnis
+kopieren. Bei einem erneuten kleingebäck-Lauf werden diese Bilder dann
+nicht überschrieben.
+
+Wir verwenden dafür einen Algorythmus namens [distance
+hashing](https://github.com/corona10/goimagehash). Dieser Algorithmus
+prüft die Ähnlichkeit von Bildern. Diese können in ihrer Auflösung,
+Kompression, Farbtiefe und vielem mehr manipuliert worden sein und
+trotzdem als das "gleiche Bild" erkannt werden (wohlgemerkt nicht "das
+selbe": die Dateien sind durchaus unterschiedlich!). Bis zu einer
+Distance von 5 überschreiben wir keine Bilder, weil wir dann davon
+ausgehen, dass das lokal Vorhandene das Original ist.
+
+Bitte beachte aber, dass dies KEIN Cachingmechanismus ist: die Bilder
+werden trotzdem immer alle heruntergeladen. Das muss so sein, da wir
+uns nicht die Dateinamen anschauen können, da kleinanzeigen.de diese
+nämlich zu Zahlen umbenennt. Und die Dateinamen können sich auch
+ändern, wenn der User in der Anzeige die Bilder umarrangiert hat.
+
+Du kannst dieses Verhalten mit der Option **--force** ausschalten. Du
+kannst ausserdem mit der Option **--ignoreerrors** auch alle Fehler
+ignorieren, die beim Bilderdownload auftreten könnten.
+
 ## Documentation
 
 Die Dokumentation kann man

README.md

@@ -207,6 +207,48 @@ variable. The supplied sample config contains the default template.
 
 All images will be stored in the same directory.
 
+## Tool Behavior
+
+There are a bunch of things you might want to know about the behavior
+of the kleingebäck tool:
+
+- all HTML pages and IMAGEs are always being downloaded
+- we use a (customizable) user agent
+- we respect HTTP cookies
+- in the case of an error, the tool does 3 retries, the time it waits
+  between tries is longer for each retry
+- image download is parallized using small time differences to look
+  more natural
+- same images are not being overwritten on subsequent download
+
+
+The latter needs to be elaborated a bit more:
+
+If you publish an ad on kleinanzeigen.de and post images, those images
+will be reduced in size by the site (by compressing and down sizing
+them). This reduced images will be downloaded by kleingebäck. However,
+you may still own the original images and may want to put them into
+that backup directory so that you have all things for one ad together.
+
+You can easily do that, because kleingebäck won't overwrite those
+original images. It uses something called a distance hash using
+[goimagehash](https://github.com/corona10/goimagehash). This
+algorithmus checks the similarity of images. If an image has been
+resized it is still very similar to the original one. We accept a
+maximum of a distance of 5, everything above leads to overwrite.
+
+This works with resizes, cropped and otherwise manipulated images as
+long as the image still shows the original contents good enough.
+
+Also note, that this is NOT a caching mechanism: the images will be
+downloaded anyway during each run. We also can't look at the file
+names because kleinanzeigen.de renames all images to numbers. And
+those might even change if the user re-arranges the images.
+
+You can override this behavior using the **--force** option. Another
+option, **--ignoreerrors**, can be used to ignore all kinds of image
+errors. 
+
 ## Documentation
 
 You can read the documentation [online](https://github.com/TLINDEN/kleingebaeck/blob/main/kleingebaeck.pod) or locally once you have installed kleingebaeck with: `kleingebaeck --manual`.

SECURITY.md

@@ -0,0 +1,17 @@
+# Security Policy
+
+## Supported Versions
+
+Only  the latest  release  is supported.  If you  find  an issue  (any
+issue!), please check with the latest release first.
+
+## Reporting a Vulnerability
+
+I don't agree with the "responsible disclosure" process most projects
+(and companies) work these days.
+
+So, if you find a vulnerability of any kind, please just open an
+[issue](https://github.com/TLINDEN/kleingebaeck/issues). Please add
+all details required to reproduce the vulnerability. You won't be chased.
+
+That's just all about it.

ad.go

@@ -73,7 +73,7 @@ func (ad *Ad) Incomplete() bool {
 }
 
 func (ad *Ad) CalculateExpire() {
-	if len(ad.Created) > 0 {
+	if ad.Created != "" {
 		ts, err := time.Parse("02.01.2006", ad.Created)
 		if err == nil {
 			ad.Expire = ts.AddDate(0, ExpireMonths, ExpireDays).Format("02.01.2006")

config.go

@@ -34,7 +34,7 @@ import (
 )
 
 const (
-	VERSION    string = "0.3.5"
+	VERSION    string = "0.3.6"
 	Baseuri    string = "https://www.kleinanzeigen.de"
 	Listuri    string = "/s-bestandsliste.html"
 	Defaultdir string = "."

fetch.go

@@ -52,7 +52,7 @@ func NewFetcher(conf *Config) (*Fetcher, error) {
 }
 
 func (f *Fetcher) Get(uri string) (io.ReadCloser, error) {
-	req, err := http.NewRequest(http.MethodGet, uri, nil)
+	req, err := http.NewRequest(http.MethodGet, uri, http.NoBody)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create a new HTTP request obj: %w", err)
 	}

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/corona10/goimagehash v1.1.0 // indirect
 	github.com/fatih/color v1.16.0 // indirect
 	github.com/fsnotify/fsnotify v1.6.0 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/knadh/koanf/maps v0.1.1 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect

go.sum

@@ -15,6 +15,8 @@ github.com/fatih/color v1.16.0 h1:zmkK9Ngbjj+K0yRhTVONQh1p/HknKYSlNT+vZCzyokM=
 github.com/fatih/color v1.16.0/go.mod h1:fL2Sau1YI5c0pdGEVCbKQbLXB6edEj1ZgiY4NijnWvE=
 github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jarcoal/httpmock v1.3.1 h1:iUx3whfZWVf3jT01hQTO/Eo5sAYtB2/rqaUuOtpInww=
 github.com/jarcoal/httpmock v1.3.1/go.mod h1:3yb8rc4BI7TCBhFY8ng0gjuLKJNquuDNiPaZjnENuYg=
 github.com/knadh/koanf/maps v0.1.1 h1:G5TjmUh2D7G2YWf5SQQqSiHRJEjaicvU0KpypqB3NIs=

image.go

@@ -49,7 +49,7 @@ func (img *Image) LogValue() slog.Value {
 // holds all images of an ad
 type Cache []*goimagehash.ImageHash
 
-func NewImage(buf *bytes.Reader, filename string, uri string) *Image {
+func NewImage(buf *bytes.Reader, filename, uri string) *Image {
 	img := &Image{
 		Filename: filename,
 		URI:      uri,
@@ -134,7 +134,7 @@ func ReadImages(addir string, dont bool) (Cache, error) {
 			reader := bytes.NewReader(data.Bytes())
 
 			img := NewImage(reader, filename, "")
-			if err = img.CalcHash(); err != nil {
+			if err := img.CalcHash(); err != nil {
 				return nil, err
 			}
 

main.go

@@ -18,13 +18,16 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package main
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
 	"io"
 	"log/slog"
 	"os"
+	"runtime"
 	"runtime/debug"
 
+	"github.com/inconshreveable/mousetrap"
 	"github.com/lmittmann/tint"
 	"github.com/tlinden/yadu"
 )
@@ -35,6 +38,25 @@ func main() {
 	os.Exit(Main(os.Stdout))
 }
 
+func init() {
+	// if we're running on Windows  AND if the user double clicked the
+	// exe  file from explorer, we  tell them and then  wait until any
+	// key has been hit, which  will make the cmd window disappear and
+	// thus give the user time to read it.
+	if runtime.GOOS == "windows" {
+		if mousetrap.StartedByExplorer() {
+			fmt.Println("Do no double click kleingebaeck.exe!")
+			fmt.Println("Please open a command shell and run it from there.")
+			fmt.Println()
+			fmt.Print("Press any key to quit: ")
+			_, err := bufio.NewReader(os.Stdin).ReadString('\n')
+			if err != nil {
+				panic(err)
+			}
+		}
+	}
+}
+
 func Main(output io.Writer) int {
 	logLevel := &slog.LevelVar{}
 	opts := &tint.Options{

main_test.go

@@ -334,14 +334,14 @@ type Adsource struct {
 }
 
 // Render a HTML template for an adlisting or an ad
-func GetTemplate(adconfigs []AdConfig, adconfig AdConfig, htmltemplate string) string {
+func GetTemplate(adconfigs []AdConfig, adconfig *AdConfig, htmltemplate string) string {
 	tmpl, err := tpl.New("template").Parse(htmltemplate)
 	if err != nil {
 		panic(err)
 	}
 
 	var out bytes.Buffer
-	if len(adconfig.ID) == 0 {
+	if adconfig.ID == "" {
 		err = tmpl.Execute(&out, adconfigs)
 	} else {
 		err = tmpl.Execute(&out, adconfig)
@@ -376,15 +376,15 @@ func InitValidSources() []Adsource {
 	ads := []Adsource{
 		{
 			uri:     fmt.Sprintf("%s%s?userId=1", Baseuri, Listuri),
-			content: GetTemplate(list1, empty, LISTTPL),
+			content: GetTemplate(list1, &empty, LISTTPL),
 		},
 		{
 			uri:     fmt.Sprintf("%s%s?userId=1&pageNum=2", Baseuri, Listuri),
-			content: GetTemplate(list2, empty, LISTTPL),
+			content: GetTemplate(list2, &empty, LISTTPL),
 		},
 		{
 			uri:     fmt.Sprintf("%s%s?userId=1&pageNum=3", Baseuri, Listuri),
-			content: GetTemplate(list3, empty, LISTTPL),
+			content: GetTemplate(list3, &empty, LISTTPL),
 		},
 	}
 
@@ -392,7 +392,7 @@ func InitValidSources() []Adsource {
 	for _, ad := range adsrc {
 		ads = append(ads, Adsource{
 			uri:     fmt.Sprintf("%s/s-anzeige/%s/%s", Baseuri, ad.Slug, ad.ID),
-			content: GetTemplate(nil, ad, ADTPL),
+			content: GetTemplate(nil, &ad, ADTPL),
 		})
 	}
 
@@ -405,28 +405,28 @@ func InitInvalidSources() []Adsource {
 		{
 			// valid ad page but without content
 			uri:     fmt.Sprintf("%s/s-anzeige/empty/1", Baseuri),
-			content: GetTemplate(nil, empty, EMPTYPAGE),
+			content: GetTemplate(nil, &empty, EMPTYPAGE),
 		},
 		{
 			// some random foreign webpage
 			uri:     INVALIDURI,
-			content: GetTemplate(nil, empty, "<html>foo</html>"),
+			content: GetTemplate(nil, &empty, "<html>foo</html>"),
 		},
 		{
 			// some invalid page path
 			uri:     fmt.Sprintf("%s/anzeige/name/1", Baseuri),
-			content: GetTemplate(nil, empty, "<html></html>"),
+			content: GetTemplate(nil, &empty, "<html></html>"),
 		},
 		{
 			// some none-ad page
 			uri:     fmt.Sprintf("%s/anzeige/name/1/foo/bar", Baseuri),
-			content: GetTemplate(nil, empty, "<html>HTTP 404: /eine-anzeige/ does not exist!</html>"),
+			content: GetTemplate(nil, &empty, "<html>HTTP 404: /eine-anzeige/ does not exist!</html>"),
 			status:  404,
 		},
 		{
 			// valid ad page but 503
 			uri:     fmt.Sprintf("%s/s-anzeige/503/1", Baseuri),
-			content: GetTemplate(nil, empty, "<html>HTTP 503: service unavailable</html>"),
+			content: GetTemplate(nil, &empty, "<html>HTTP 503: service unavailable</html>"),
 			status:  503,
 		},
 	}
@@ -465,7 +465,7 @@ func SetIntercept(ads []Adsource) {
 	}
 }
 
-func VerifyAd(advertisement AdConfig) error {
+func VerifyAd(advertisement *AdConfig) error {
 	body := advertisement.Title + advertisement.Price + advertisement.ID + "Kleinanzeigen => " +
 		advertisement.Category + advertisement.Condition + advertisement.Created
 
@@ -525,7 +525,7 @@ func TestMain(t *testing.T) {
 
 	// verify if downloaded ads match
 	for _, ad := range adsrc {
-		if err := VerifyAd(ad); err != nil {
+		if err := VerifyAd(&ad); err != nil {
 			t.Errorf(err.Error())
 		}
 	}