Add kgz, a gzip tool.
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@ -25,6 +25,8 @@ Contents:
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csrpubdump/ Dump the public key from an X.509 certificate request.
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fragment/ Print a fragment of a file.
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jlp/ JSON linter/prettifier.
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kgz/ Custom gzip compressor / decompressor that handles 99%
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of my use cases.
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pem2bin/ Dump the binary body of a PEM-encoded block.
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pembody/ Print the body of a PEM certificate.
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pemit/ Dump data to a PEM file.
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@ -0,0 +1,23 @@
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kgz
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kgz is like gzip, but supports compressing and decompressing to a different
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directory than the source file is in.
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Usage: kgz [-l] source [target]
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If target is a directory, the basename of the sourcefile will be used
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as the target filename. Compression and decompression is selected
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based on whether the source filename ends in ".gz".
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Flags:
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-l level Compression level (0-9). Only meaninful when
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compressing a file.
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@ -0,0 +1,182 @@
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package main
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import (
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"compress/flate"
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"compress/gzip"
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"flag"
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"fmt"
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"io"
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"os"
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"path/filepath"
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"strings"
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"github.com/pkg/errors"
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)
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const gzipExt = ".gz"
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func compress(path, target string, level int) error {
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sourceFile, err := os.Open(path)
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if err != nil {
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return errors.Wrap(err, "opening file for read")
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}
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defer sourceFile.Close()
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destFile, err := os.Create(target)
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if err != nil {
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return errors.Wrap(err, "opening file for write")
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}
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defer destFile.Close()
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gzipCompressor, err := gzip.NewWriterLevel(destFile, level)
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if err != nil {
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return errors.Wrap(err, "invalid compression level")
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}
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defer gzipCompressor.Close()
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_, err = io.Copy(gzipCompressor, sourceFile)
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if err != nil {
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return errors.Wrap(err, "compressing file")
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}
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if err != nil {
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return errors.Wrap(err, "stat(2)ing destination file")
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}
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return nil
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}
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func uncompress(path, target string) error {
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sourceFile, err := os.Open(path)
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if err != nil {
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return errors.Wrap(err, "opening file for read")
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}
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defer sourceFile.Close()
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gzipUncompressor, err := gzip.NewReader(sourceFile)
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if err != nil {
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return errors.Wrap(err, "reading gzip headers")
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}
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defer gzipUncompressor.Close()
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destFile, err := os.Create(target)
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if err != nil {
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return errors.Wrap(err, "opening file for write")
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}
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defer destFile.Close()
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_, err = io.Copy(destFile, gzipUncompressor)
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if err != nil {
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return errors.Wrap(err, "uncompressing file")
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}
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return nil
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}
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func usage(w io.Writer) {
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fmt.Fprintf(w, `Usage: %s [-l] source [target]
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kgz is like gzip, but supports compressing and decompressing to a different
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directory than the source file is in.
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Flags:
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-l level Compression level (0-9). Only meaninful when
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compressing a file.
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`, os.Args[0])
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}
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func init() {
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flag.Usage = func() { usage(os.Stderr) }
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}
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func isDir(path string) bool {
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file, err := os.Open(path)
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if err == nil {
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defer file.Close()
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stat, err := file.Stat()
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if err != nil {
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return false
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}
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if stat.IsDir() {
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return true
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}
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}
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return false
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}
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func pathForUncompressing(source, dest string) (string, error) {
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if !isDir(dest) {
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return dest, nil
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}
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source = filepath.Base(source)
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if !strings.HasSuffix(source, gzipExt) {
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return "", errors.Errorf("%s is a not gzip-compressed file")
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}
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outFile := source[:len(source)-len(gzipExt)]
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outFile = filepath.Join(dest, outFile)
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return outFile, nil
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}
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func pathForCompressing(source, dest string) (string, error) {
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if !isDir(dest) {
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return dest, nil
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}
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source = filepath.Base(source)
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if strings.HasSuffix(source, gzipExt) {
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return "", errors.Errorf("%s is a gzip-compressed file")
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}
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dest = filepath.Join(dest, source+gzipExt)
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return dest, nil
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}
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func main() {
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var level int
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var path string
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var target = "."
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flag.IntVar(&level, "l", flate.DefaultCompression, "compression level")
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flag.Parse()
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if flag.NArg() < 1 || flag.NArg() > 2 {
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usage(os.Stderr)
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os.Exit(1)
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}
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path = flag.Arg(0)
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if flag.NArg() == 2 {
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target = flag.Arg(1)
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}
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if strings.HasSuffix(path, gzipExt) {
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target, err := pathForUncompressing(path, target)
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if err != nil {
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fmt.Fprintf(os.Stderr, "%s\n", err)
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os.Exit(1)
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}
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err = uncompress(path, target)
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if err != nil {
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os.Remove(target)
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fmt.Fprintf(os.Stderr, "%s\n", err)
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os.Exit(1)
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}
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} else {
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target, err := pathForCompressing(path, target)
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if err != nil {
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fmt.Fprintf(os.Stderr, "%s\n", err)
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os.Exit(1)
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}
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err = compress(path, target, level)
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if err != nil {
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os.Remove(target)
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fmt.Fprintf(os.Stderr, "%s\n", err)
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os.Exit(1)
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}
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}
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}
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