From 9715293773f68bcbb2874488e862ae95d7ed2b88 Mon Sep 17 00:00:00 2001
From: Kyle Isom <kyle@imap.cc>
Date: Sun, 19 May 2024 20:41:50 -0700
Subject: [PATCH] Add zsearch and dumpbytes.

---
 cmd/dumpbytes/main.go |  71 ++++++++++++++++++++++
 cmd/zsearch/main.go   | 136 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 207 insertions(+)
 create mode 100644 cmd/dumpbytes/main.go
 create mode 100644 cmd/zsearch/main.go

diff --git a/cmd/dumpbytes/main.go b/cmd/dumpbytes/main.go
new file mode 100644
index 0000000..defccbc
--- /dev/null
+++ b/cmd/dumpbytes/main.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"git.wntrmute.dev/kyle/goutils/die"
+	"io"
+	"os"
+)
+
+func usage(w io.Writer, exc int) {
+	fmt.Fprintln(w, `usage: dumpbytes <file>`)
+	os.Exit(exc)
+}
+
+func printBytes(buf []byte) {
+	fmt.Printf("\t")
+	for i := 0; i < len(buf); i++ {
+		fmt.Printf("0x%02x, ", buf[i])
+	}
+	fmt.Println()
+}
+
+func dumpFile(path string, indentLevel int) error {
+	indent := ""
+	for i := 0; i < indentLevel; i++ {
+		indent += "\t"
+	}
+
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	fmt.Printf("%svar buffer = []byte{\n", indent)
+	for {
+		buf := make([]byte, 8)
+		n, err := file.Read(buf)
+		if err == io.EOF {
+			if n > 0 {
+				fmt.Printf("%s", indent)
+				printBytes(buf[:n])
+			}
+			break
+		}
+
+		if err != nil {
+			return err
+		}
+
+		fmt.Printf("%s", indent)
+		printBytes(buf[:n])
+	}
+
+	fmt.Printf("%s}\n", indent)
+	return nil
+}
+
+func main() {
+	indent := 0
+	flag.Usage = func() { usage(os.Stderr, 0) }
+	flag.IntVar(&indent, "n", 0, "indent level")
+	flag.Parse()
+
+	for _, file := range flag.Args() {
+		err := dumpFile(file, indent)
+		die.If(err)
+	}
+}
diff --git a/cmd/zsearch/main.go b/cmd/zsearch/main.go
new file mode 100644
index 0000000..c2c9adc
--- /dev/null
+++ b/cmd/zsearch/main.go
@@ -0,0 +1,136 @@
+// zsearch is a utility for searching zlib-compressed files for a
+// search string. It was really designed for use with the Git object
+// store, i.e. to aid in the recovery of files after Git does what Git
+// do.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"compress/zlib"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+const defaultDirectory = ".git/objects"
+
+func errorf(format string, a ...interface{}) {
+	fmt.Fprintf(os.Stderr, format, a...)
+	if format[len(format)-1] != '\n' {
+		fmt.Fprintf(os.Stderr, "\n")
+	}
+}
+
+func isDir(path string) bool {
+	fi, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+
+	return fi.IsDir()
+}
+
+func loadFile(path string) ([]byte, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	buf := new(bytes.Buffer)
+	zread, err := zlib.NewReader(file)
+	if err != nil {
+		return nil, err
+	}
+	defer zread.Close()
+
+	_, err = io.Copy(buf, zread)
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func showFile(path string) {
+	fileData, err := loadFile(path)
+	if err != nil {
+		errorf("%v", err)
+		return
+	}
+
+	fmt.Printf("%s\n", fileData)
+}
+
+func searchFile(path string, search *regexp.Regexp) error {
+	file, err := os.Open(path)
+	if err != nil {
+		errorf("%v")
+		return err
+	}
+	defer file.Close()
+
+	zread, err := zlib.NewReader(file)
+	if err != nil {
+		errorf("%v", err)
+		return err
+	}
+	defer zread.Close()
+
+	zbuf := bufio.NewReader(zread)
+	if search.MatchReader(zbuf) {
+		fileData, err := loadFile(path)
+		if err != nil {
+			errorf("%v", err)
+			return err
+		}
+		fmt.Printf("%s:\n%s\n", path, fileData)
+	}
+	return nil
+}
+
+func buildWalker(searchExpr *regexp.Regexp) filepath.WalkFunc {
+	return func(path string, info os.FileInfo, err error) error {
+		if info.Mode().IsRegular() {
+			return searchFile(path, searchExpr)
+		}
+		return nil
+	}
+}
+
+func main() {
+	flSearch := flag.String("s", "", "search string (should be an RE2 regular expression)")
+	flag.Parse()
+
+	if *flSearch == "" {
+		for _, path := range flag.Args() {
+			showFile(path)
+		}
+	} else {
+		search, err := regexp.Compile(*flSearch)
+		if err != nil {
+			errorf("Bad regexp: %v", err)
+			return
+		}
+
+		pathList := flag.Args()
+		if len(pathList) == 0 {
+			pathList = []string{defaultDirectory}
+		}
+
+		for _, path := range pathList {
+			if isDir(path) {
+				err := filepath.Walk(path, buildWalker(search))
+				if err != nil {
+					errorf("%v", err)
+					return
+				}
+			} else {
+				searchFile(path, search)
+			}
+		}
+	}
+}