From: Sergey Matveev <stargrave@stargrave.org>
Date: Sun, 7 Apr 2024 09:43:33 +0000 (+0300)
Subject: Ability to download URLs
X-Git-Tag: v0.9.0^0
X-Git-Url: http://www.git.stargrave.org/?p=meta4ra.git;a=commitdiff_plain

Ability to download URLs
---

diff --git a/README b/README
index 8f71194..0f8a2f0 100644
--- a/README
+++ b/README
@@ -5,7 +5,7 @@ meta4ra-create utility is used to create Metalink4
 .meta4-file for single specified file.
 
 meta4ra-check utility is used to check .meta4 file, extract signatures
-and verify corresponding files integrity.
+and verify corresponding files integrity. Optionally download files.
 
 meta4ra-hash utility can be used to hash the data with a single hash
 algorithm. It could be useful if you want to use the best found
diff --git a/cmd/meta4ra/check.go b/cmd/meta4ra/check.go
index 3b3e0a9..95511c0 100644
--- a/cmd/meta4ra/check.go
+++ b/cmd/meta4ra/check.go
@@ -23,6 +23,7 @@ import (
 	"io"
 	"io/fs"
 	"log"
+	"net/http"
 	"os"
 	"path"
 	"strings"
@@ -37,6 +38,7 @@ func runCheck() {
 		"hash-name:commandline[,...]")
 	extractSig := flag.Bool("extract-sig", false, "Extract signature files")
 	metaPath := flag.String("meta4", "file.meta4", "Metalink file")
+	dl := flag.Int("dl", -1, "URL index to download, instead of reading from stdin")
 	flag.Usage = func() {
 		fmt.Fprintf(flag.CommandLine.Output(),
 			"Usage: %s [options] [FILE ...]\n", os.Args[0])
@@ -46,6 +48,10 @@ If no FILEs are specified, then all <file>s from metalink are searched and
 verified if they exist. Otherwise only specified FILEs are checked. If you
 want to skip any <file> verification (for example only to validate the format
 and -extract-sig, then you can just specify an empty ("") FILE.
+
+If -dl (> 0) is specified, then it automatically implies -pipe, but
+downloads data by specified URLs index, instead of reading from stdin.
+That can be used as a downloading utility.
 `)
 	}
 	flag.Parse()
@@ -73,6 +79,9 @@ and -extract-sig, then you can just specify an empty ("") FILE.
 	for _, fn := range flag.Args() {
 		toCheck[path.Base(fn)] = fn
 	}
+	if *dl != -1 {
+		*pipe = true
+	}
 	if *pipe && len(toCheck) != 1 {
 		log.Fatalln("exactly single FILE must be specified when using -pipe")
 	}
@@ -155,19 +164,38 @@ and -extract-sig, then you can just specify an empty ("") FILE.
 		continue
 	HashFound:
 
-		fd := os.Stdin
+		var src io.ReadCloser
+		src = os.Stdin
 		if !*pipe {
-			fd, err = os.Open(fullPath)
+			src, err = os.Open(fullPath)
 			if err != nil {
 				log.Println("Error:", f.Name, err)
 				bad = true
 				continue
 			}
 		}
+		if *dl != -1 {
+			resp, err := http.Get(f.URLs[*dl].URL)
+			if err != nil {
+				log.Println("Error:", f.Name, err)
+				bad = true
+				continue
+			}
+			log.Println("HTTP response:")
+			for k := range resp.Header {
+				log.Println("\t"+k+":", resp.Header.Get(k))
+			}
+			if resp.StatusCode != http.StatusOK {
+				log.Println("Bad status code:", f.Name, resp.Status)
+				bad = true
+				continue
+			}
+			src = resp.Body
+		}
 		err = hasher.Start()
 		if err != nil {
 			if !*pipe {
-				fd.Close()
+				src.Close()
 			}
 			hasher.Stop()
 			log.Println("Error:", f.Name, err)
@@ -180,9 +208,9 @@ and -extract-sig, then you can just specify an empty ("") FILE.
 		} else {
 			w = hasher
 		}
-		_, err = io.Copy(w, bufio.NewReaderSize(fd, meta4ra.BufLen))
-		if !*pipe {
-			fd.Close()
+		_, err = io.Copy(w, bufio.NewReaderSize(src, meta4ra.BufLen))
+		if !*pipe || *dl != -1 {
+			src.Close()
 		}
 		if err != nil {
 			hasher.Stop()
diff --git a/internal/common.go b/internal/common.go
index cc62ce7..5f52548 100644
--- a/internal/common.go
+++ b/internal/common.go
@@ -21,7 +21,7 @@ import (
 )
 
 const (
-	Generator       = "meta4ra/0.8.0"
+	Generator       = "meta4ra/0.9.0"
 	SigMediaTypePGP = "application/pgp-signature"
 	SigMediaTypeSSH = "application/ssh-signature"
 	BufLen          = 1 << 20