From 6f66040e098c4f53ecb288be12e59b74547911c4 Mon Sep 17 00:00:00 2001
From: Shane C <shane@scaffoe.com>
Date: Sun, 8 Dec 2024 20:50:43 -0500
Subject: [PATCH] Add ExtractFile function

---
 archive.go      | 11 +++++++++++
 archive_test.go | 50 +++++++++++++++++++++++++++++++++++++++++++++++++
 open.go         | 24 ++++++++++++++++++++++++
 3 files changed, 85 insertions(+)

diff --git a/archive.go b/archive.go
index a18d799..953527e 100644
--- a/archive.go
+++ b/archive.go
@@ -141,6 +141,17 @@ func (a *Archive) Extract(opts ExtractOptions) error {
 	return extract(Filesystem{file: true}, opts, a)
 }
 
+// ExtractFile extracts a specified file from an archive to a specified directory.
+// It takes a file path, and ExtractFileOptions as its parameters.
+// The function returns an error, if any.
+func (a *Archive) ExtractFile(path string, opts ExtractFileOptions) error {
+	file, err := a.GetFile(path)
+	if err != nil {
+		return err
+	}
+	return file.Extract(opts)
+}
+
 // Close closes the Archive.
 // The function returns an error, if any.
 func (a *Archive) Close() error {
diff --git a/archive_test.go b/archive_test.go
index 293f311..3ba3a7a 100644
--- a/archive_test.go
+++ b/archive_test.go
@@ -92,30 +92,80 @@ func TestArchiveExtract(t *testing.T) {
 	})
 	assert.NoError(t, err)
 
+	err = os.RemoveAll(testArchiveBaseDir + "/extracted/zip")
+	assert.NoError(t, err)
+
+	t.Log("== ExtractFileZip ==")
+	err = ExtractFile(testArchiveBaseDir+"/test.zip", "test1.txt", ExtractFileOptions{
+		Folder: testArchiveBaseDir + "/extracted/zip",
+	})
+	assert.NoError(t, err)
+	assert.FileExists(t, testArchiveBaseDir+"/extracted/zip/test1.txt")
+
 	t.Log("== ExtractTar ==")
 	err = Extract(testArchiveBaseDir+"/test.tar", ExtractOptions{
 		Folder: testArchiveBaseDir + "/extracted/tar",
 	})
 	assert.NoError(t, err)
 
+	err = os.RemoveAll(testArchiveBaseDir + "/extracted/tar")
+	assert.NoError(t, err)
+
+	t.Log("== ExtractFileTar ==")
+	err = ExtractFile(testArchiveBaseDir+"/test.tar", "test1.txt", ExtractFileOptions{
+		Folder: testArchiveBaseDir + "/extracted/tar",
+	})
+	assert.NoError(t, err)
+	assert.FileExists(t, testArchiveBaseDir+"/extracted/tar/test1.txt")
+
 	t.Log("== ExtractTarXz ==")
 	err = Extract(testArchiveBaseDir+"/test.tar.xz", ExtractOptions{
 		Folder: testArchiveBaseDir + "/extracted/xz",
 	})
 	assert.NoError(t, err)
 
+	err = os.RemoveAll(testArchiveBaseDir + "/extracted/xz")
+	assert.NoError(t, err)
+
+	t.Log("== ExtractFileTarXz ==")
+	err = ExtractFile(testArchiveBaseDir+"/test.tar.xz", "test1.txt", ExtractFileOptions{
+		Folder: testArchiveBaseDir + "/extracted/xz",
+	})
+	assert.NoError(t, err)
+	assert.FileExists(t, testArchiveBaseDir+"/extracted/xz/test1.txt")
+
 	t.Log("== ExtractTarBz ==")
 	err = Extract(testArchiveBaseDir+"/test.tar.bz2", ExtractOptions{
 		Folder: testArchiveBaseDir + "/extracted/bzip",
 	})
 	assert.NoError(t, err)
 
+	err = os.RemoveAll(testArchiveBaseDir + "/extracted/bzip")
+	assert.NoError(t, err)
+
+	t.Log("== ExtractFileTarBz ==")
+	err = ExtractFile(testArchiveBaseDir+"/test.tar.bz2", "test1.txt", ExtractFileOptions{
+		Folder: testArchiveBaseDir + "/extracted/bzip",
+	})
+	assert.NoError(t, err)
+	assert.FileExists(t, testArchiveBaseDir+"/extracted/bzip/test1.txt")
+
 	t.Log("== ExtractTarGz ==")
 	err = Extract(testArchiveBaseDir+"/test.tar.gz", ExtractOptions{
 		Folder: testArchiveBaseDir + "/extracted/gz",
 	})
 	assert.NoError(t, err)
 
+	err = os.RemoveAll(testArchiveBaseDir + "/extracted/gz")
+	assert.NoError(t, err)
+
+	t.Log("== ExtractFileTarGz ==")
+	err = ExtractFile(testArchiveBaseDir+"/test.tar.gz", "test1.txt", ExtractFileOptions{
+		Folder: testArchiveBaseDir + "/extracted/gz",
+	})
+	assert.NoError(t, err)
+	assert.FileExists(t, testArchiveBaseDir+"/extracted/gz/test1.txt")
+
 	err = os.RemoveAll(testArchiveBaseDir + "/extracted")
 	assert.NoError(t, err)
 
diff --git a/open.go b/open.go
index 4953d73..3e6b699 100644
--- a/open.go
+++ b/open.go
@@ -69,6 +69,30 @@ func Extract(path string, options ExtractOptions) error {
 	return nil
 }
 
+// ExtractFile opens an archive file and extracts a specific file within the archive.
+// It takes a path, a file path, and ExtractFileOptions for its parameters.
+// The function returns an error, if any.
+func ExtractFile(path string, file string, options ExtractFileOptions) error {
+	archive, err := Open(path)
+	if err != nil {
+		return err
+	}
+	defer archive.Close()
+
+	archiveFile, err := archive.GetFile(file)
+	if err != nil {
+		return err
+	}
+
+	if err := archiveFile.Extract(options); err != nil {
+		return err
+	}
+	if err := archive.Close(); err != nil {
+		return err
+	}
+	return nil
+}
+
 func openArchive(filesystem Filesystem, path string) (*Archive, error) {
 	archive := new(Archive)
 	archive.files = make(map[string]*File)