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Adding upstream version 0.0~git20190502.809d437.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-05-18 17:48:16 +02:00
parent dbb9ae2240
commit 289829de85
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
12 changed files with 575 additions and 0 deletions
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.gitignore vendored Normal file
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*.*~

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COPYING Normal file
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Copyright (c) 2013 Blake Smith <blakesmith0@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

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# Golang ar (archive) file reader
This is a simple library for reading and writing [ar](http://en.wikipedia.org/wiki/Ar_(Unix)) files in common format. It is influenced heavily in style and interface from the golang [tar](http://golang.org/pkg/archive/tar/) package.
## Author
Written by Blake Smith <blakesmith0@gmail.com>
Licensed under the MIT license.

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/*
Copyright (c) 2013 Blake Smith <blakesmith0@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package ar
import (
"time"
)
const (
HEADER_BYTE_SIZE = 60
GLOBAL_HEADER = "!<arch>\n"
)
type Header struct {
Name string
ModTime time.Time
Uid int
Gid int
Mode int64
Size int64
}
type slicer []byte
func (sp *slicer) next(n int) (b []byte) {
s := *sp
b, *sp = s[0:n], s[n:]
return
}

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!<arch>
hello.txt 1361157466 501 20 100644 13 `
Hello world!

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Hello world!

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fixtures/lamp.txt Normal file
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I love lamp.

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!<arch>
hello.txt 1361157466 501 20 100644 13 `
Hello world!
lamp.txt 1361248906 501 20 100644 13 `
I love lamp.

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/*
Copyright (c) 2013 Blake Smith <blakesmith0@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package ar
import (
"io"
"io/ioutil"
"os"
"strconv"
"time"
)
// Provides read access to an ar archive.
// Call next to skip files
//
// Example:
// reader := NewReader(f)
// var buf bytes.Buffer
// for {
// _, err := reader.Next()
// if err == io.EOF {
// break
// }
// if err != nil {
// t.Errorf(err.Error())
// }
// io.Copy(&buf, reader)
// }
type Reader struct {
r io.Reader
nb int64
pad int64
}
// Copies read data to r. Strips the global ar header.
func NewReader(r io.Reader) *Reader {
io.CopyN(ioutil.Discard, r, 8) // Discard global header
return &Reader{r: r}
}
func (rd *Reader) string(b []byte) string {
i := len(b)-1
for i > 0 && b[i] == 32 {
i--
}
return string(b[0:i+1])
}
func (rd *Reader) numeric(b []byte) int64 {
i := len(b)-1
for i > 0 && b[i] == 32 {
i--
}
n, _ := strconv.ParseInt(string(b[0:i+1]), 10, 64)
return n
}
func (rd *Reader) octal(b []byte) int64 {
i := len(b)-1
for i > 0 && b[i] == 32 {
i--
}
n, _ := strconv.ParseInt(string(b[3:i+1]), 8, 64)
return n
}
func (rd *Reader) skipUnread() error {
skip := rd.nb + rd.pad
rd.nb, rd.pad = 0, 0
if seeker, ok := rd.r.(io.Seeker); ok {
_, err := seeker.Seek(skip, os.SEEK_CUR)
return err
}
_, err := io.CopyN(ioutil.Discard, rd.r, skip)
return err
}
func (rd *Reader) readHeader() (*Header, error) {
headerBuf := make([]byte, HEADER_BYTE_SIZE)
if _, err := io.ReadFull(rd.r, headerBuf); err != nil {
return nil, err
}
header := new(Header)
s := slicer(headerBuf)
header.Name = rd.string(s.next(16))
header.ModTime = time.Unix(rd.numeric(s.next(12)), 0)
header.Uid = int(rd.numeric(s.next(6)))
header.Gid = int(rd.numeric(s.next(6)))
header.Mode = rd.octal(s.next(8))
header.Size = rd.numeric(s.next(10))
rd.nb = int64(header.Size)
if header.Size%2 == 1 {
rd.pad = 1
} else {
rd.pad = 0
}
return header, nil
}
// Call Next() to skip to the next file in the archive file.
// Returns a Header which contains the metadata about the
// file in the archive.
func (rd *Reader) Next() (*Header, error) {
err := rd.skipUnread()
if err != nil {
return nil, err
}
return rd.readHeader()
}
// Read data from the current entry in the archive.
func (rd *Reader) Read(b []byte) (n int, err error) {
if rd.nb == 0 {
return 0, io.EOF
}
if int64(len(b)) > rd.nb {
b = b[0:rd.nb]
}
n, err = rd.r.Read(b)
rd.nb -= int64(n)
return
}

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/*
Copyright (c) 2013 Blake Smith <blakesmith0@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package ar
import (
"bytes"
"io"
"os"
"testing"
"time"
)
func TestReadHeader(t *testing.T) {
f, err := os.Open("./fixtures/hello.a")
defer f.Close()
if err != nil {
t.Errorf(err.Error())
}
reader := NewReader(f)
header, err := reader.Next()
if err != nil {
t.Errorf(err.Error())
}
expectedName := "hello.txt"
if header.Name != expectedName {
t.Errorf("Header name should be %s but is %s", expectedName, header.Name)
}
expectedModTime := time.Unix(1361157466, 0)
if header.ModTime != expectedModTime {
t.Errorf("ModTime should be %s but is %s", expectedModTime, header.ModTime)
}
expectedUid := 501
if header.Uid != expectedUid {
t.Errorf("Uid should be %d but is %d", expectedUid, header.Uid)
}
expectedGid := 20
if header.Gid != expectedGid {
t.Errorf("Gid should be %d but is %d", expectedGid, header.Gid)
}
expectedMode := int64(0644)
if header.Mode != expectedMode {
t.Errorf("Mode should be %d but is %d", expectedMode, header.Mode)
}
}
func TestReadBody(t *testing.T) {
f, err := os.Open("./fixtures/hello.a")
defer f.Close()
if err != nil {
t.Errorf(err.Error())
}
reader := NewReader(f)
_, err = reader.Next()
if err != nil && err != io.EOF {
t.Errorf(err.Error())
}
var buf bytes.Buffer
io.Copy(&buf, reader)
expected := []byte("Hello world!\n")
actual := buf.Bytes()
if !bytes.Equal(actual, expected) {
t.Errorf("Data value should be %s but is %s", expected, actual)
}
}
func TestReadMulti(t *testing.T) {
f, err := os.Open("./fixtures/multi_archive.a")
defer f.Close()
if err != nil {
t.Errorf(err.Error())
}
reader := NewReader(f)
var buf bytes.Buffer
for {
_, err := reader.Next()
if err == io.EOF {
break
}
if err != nil {
t.Errorf(err.Error())
}
io.Copy(&buf, reader)
}
expected := []byte("Hello world!\nI love lamp.\n")
actual := buf.Bytes()
if !bytes.Equal(expected, actual) {
t.Errorf("Concatted byte buffer should be %s but is %s", expected, actual)
}
}

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/*
Copyright (c) 2013 Blake Smith <blakesmith0@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package ar
import (
"errors"
"io"
"strconv"
)
var (
ErrWriteTooLong = errors.New("ar: write too long")
)
// Writer provides sequential writing of an ar archive.
// An ar archive is sequence of header file pairs
// Call WriteHeader to begin writing a new file, then call Write to supply the file's data
//
// Example:
// archive := ar.NewWriter(writer)
// archive.WriteGlobalHeader()
// header := new(ar.Header)
// header.Size = 15 // bytes
// if err := archive.WriteHeader(header); err != nil {
// return err
// }
// io.Copy(archive, data)
type Writer struct {
w io.Writer
nb int64 // number of unwritten bytes for the current file entry
}
// Create a new ar writer that writes to w
func NewWriter(w io.Writer) *Writer { return &Writer{w: w} }
func (aw *Writer) numeric(b []byte, x int64) {
s := strconv.FormatInt(x, 10)
for len(s) < len(b) {
s = s + " "
}
copy(b, []byte(s))
}
func (aw *Writer) octal(b []byte, x int64) {
s := "100" + strconv.FormatInt(x, 8)
for len(s) < len(b) {
s = s + " "
}
copy(b, []byte(s))
}
func (aw *Writer) string(b []byte, str string) {
s := str
for len(s) < len(b) {
s = s + " "
}
copy(b, []byte(s))
}
// Writes to the current entry in the ar archive
// Returns ErrWriteTooLong if more than header.Size
// bytes are written after a call to WriteHeader
func (aw *Writer) Write(b []byte) (n int, err error) {
if int64(len(b)) > aw.nb {
b = b[0:aw.nb]
err = ErrWriteTooLong
}
n, werr := aw.w.Write(b)
aw.nb -= int64(n)
if werr != nil {
return n, werr
}
if len(b)%2 == 1 { // data size must be aligned to an even byte
n2, _ := aw.w.Write([]byte{'\n'})
return n+n2, err
}
return
}
func (aw *Writer) WriteGlobalHeader() error {
_, err := aw.w.Write([]byte(GLOBAL_HEADER))
return err
}
// Writes the header to the underlying writer and prepares
// to receive the file payload
func (aw *Writer) WriteHeader(hdr *Header) error {
aw.nb = int64(hdr.Size)
header := make([]byte, HEADER_BYTE_SIZE)
s := slicer(header)
aw.string(s.next(16), hdr.Name)
aw.numeric(s.next(12), hdr.ModTime.Unix())
aw.numeric(s.next(6), int64(hdr.Uid))
aw.numeric(s.next(6), int64(hdr.Gid))
aw.octal(s.next(8), hdr.Mode)
aw.numeric(s.next(10), hdr.Size)
aw.string(s.next(2), "`\n")
_, err := aw.w.Write(header)
return err
}

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/*
Copyright (c) 2013 Blake Smith <blakesmith0@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package ar
import (
"bytes"
"io/ioutil"
"os"
"testing"
"time"
)
func TestGlobalHeaderWrite(t *testing.T) {
var buf bytes.Buffer
writer := NewWriter(&buf)
if err := writer.WriteGlobalHeader(); err != nil {
t.Errorf(err.Error())
}
globalHeader := buf.Bytes()
expectedHeader := []byte("!<arch>\n")
if !bytes.Equal(globalHeader, expectedHeader) {
t.Errorf("Global header should be %s but is %s", expectedHeader, globalHeader)
}
}
func TestSimpleFile(t *testing.T) {
hdr := new(Header)
body := "Hello world!\n"
hdr.ModTime = time.Unix(1361157466, 0)
hdr.Name = "hello.txt"
hdr.Size = int64(len(body))
hdr.Mode = 0644
hdr.Uid = 501
hdr.Gid = 20
var buf bytes.Buffer
writer := NewWriter(&buf)
writer.WriteGlobalHeader()
writer.WriteHeader(hdr)
_, err := writer.Write([]byte(body))
if err != nil {
t.Errorf(err.Error())
}
f, _ := os.Open("./fixtures/hello.a")
defer f.Close()
b, err := ioutil.ReadAll(f)
if err != nil {
t.Errorf(err.Error())
}
actual := buf.Bytes()
if !bytes.Equal(b, actual) {
t.Errorf("Expected %s to equal %s", actual, b)
}
}
func TestWriteTooLong(t *testing.T) {
body := "Hello world!\n"
hdr := new(Header)
hdr.Size = 1
var buf bytes.Buffer
writer := NewWriter(&buf)
writer.WriteHeader(hdr)
_, err := writer.Write([]byte(body))
if err != ErrWriteTooLong {
t.Errorf("Error should have been: %s", ErrWriteTooLong)
}
}