1 files changed, 126 insertions, 0 deletions
diff --git a/src/mime/type_unix.go b/src/mime/type_unix.go
new file mode 100644
index 0000000..649d900
--- /dev/null
+++ b/src/mime/type_unix.go
@@ -0,0 +1,126 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || (js && wasm)
+
+package mime
+
+import (
+	"bufio"
+	"os"
+	"strings"
+)
+
+func init() {
+	osInitMime = initMimeUnix
+}
+
+// See https://specifications.freedesktop.org/shared-mime-info-spec/shared-mime-info-spec-0.21.html
+// for the FreeDesktop Shared MIME-info Database specification.
+var mimeGlobs = []string{
+	"/usr/local/share/mime/globs2",
+	"/usr/share/mime/globs2",
+}
+
+// Common locations for mime.types files on unix.
+var typeFiles = []string{
+	"/etc/mime.types",
+	"/etc/apache2/mime.types",
+	"/etc/apache/mime.types",
+	"/etc/httpd/conf/mime.types",
+}
+
+func loadMimeGlobsFile(filename string) error {
+	f, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		// Each line should be of format: weight:mimetype:glob[:morefields...]
+		fields := strings.Split(scanner.Text(), ":")
+		if len(fields) < 3 || len(fields[0]) < 1 || len(fields[2]) < 3 {
+			continue
+		} else if fields[0][0] == '#' || fields[2][0] != '*' || fields[2][1] != '.' {
+			continue
+		}
+
+		extension := fields[2][1:]
+		if strings.ContainsAny(extension, "?*[") {
+			// Not a bare extension, but a glob. Ignore for now:
+			// - we do not have an implementation for this glob
+			//   syntax (translation to path/filepath.Match could
+			//   be possible)
+			// - support for globs with weight ordering would have
+			//   performance impact to all lookups to support the
+			//   rarely seen glob entries
+			// - trying to match glob metacharacters literally is
+			//   not useful
+			continue
+		}
+		if _, ok := mimeTypes.Load(extension); ok {
+			// We've already seen this extension.
+			// The file is in weight order, so we keep
+			// the first entry that we see.
+			continue
+		}
+
+		setExtensionType(extension, fields[1])
+	}
+	if err := scanner.Err(); err != nil {
+		panic(err)
+	}
+	return nil
+}
+
+func loadMimeFile(filename string) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) <= 1 || fields[0][0] == '#' {
+			continue
+		}
+		mimeType := fields[0]
+		for _, ext := range fields[1:] {
+			if ext[0] == '#' {
+				break
+			}
+			setExtensionType("."+ext, mimeType)
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		panic(err)
+	}
+}
+
+func initMimeUnix() {
+	for _, filename := range mimeGlobs {
+		if err := loadMimeGlobsFile(filename); err == nil {
+			return // Stop checking more files if mimetype database is found.
+		}
+	}
+
+	// Fallback if no system-generated mimetype database exists.
+	for _, filename := range typeFiles {
+		loadMimeFile(filename)
+	}
+}
+
+func initMimeForTests() map[string]string {
+	mimeGlobs = []string{""}
+	typeFiles = []string{"testdata/test.types"}
+	return map[string]string{
+		".T1":  "application/test",
+		".t2":  "text/test; charset=utf-8",
+		".png": "image/png",
+	}
+}