be inefficient for allocating only small amounts of small Go values. They're
best used in bulk, on the order of MiB of memory allocated on each use.

Note that by allowing for this limited form of manual memory allocation
that use-after-free bugs are possible with regular Go values. This package
limits the impact of these use-after-free bugs by preventing reuse of freed

	}
}

type repeatedByte struct {
	off int64
	b   byte
	n   int64
}

// rleBuffer is a run-length-encoded byte buffer.
// It's an io.Writer (like a bytes.Buffer) and also an io.ReaderAt,
// allowing random-access reads.
type rleBuffer struct {
	buf []repeatedByte
}

func (r *rleBuffer) Size() int64 {
	if len(r.buf) == 0 {
		return 0
	}
	last := &r.buf[len(r.buf)-1]
	return last.off + last.n

// standardize or extend the V7 format to overcome its limitations.
// The most common formats are the USTAR, PAX, and GNU formats,
// each with their own advantages and limitations.
//
// The following table captures the capabilities of each format:
//
//	                  |  USTAR |       PAX |       GNU
//	------------------+--------+-----------+----------
//	Name              |   256B | unlimited | unlimited

//go:build ignore

// detect attempts to autodetect the correct
// values of the environment variables
// used by go_ios_exec.
// detect shells out to ideviceinfo, a third party program that can
// be obtained by following the instructions at
// https://github.com/libimobiledevice/libimobiledevice.
package main

import (
	"bytes"
	"crypto/x509"
	"fmt"
	"os"
	"os/exec"
	"strings"
)

func main() {

	if !ok {
		return 0
	}
	var op int16
	switch p.next().ScanToken {
	case lex.LSH:
		op = 0
	case lex.RSH:
		op = 1
	case lex.ARR:
		op = 2
	case lex.ROT:
		// following instructions on ARM64 support rotate right
		// AND, ANDS, TST, BIC, BICS, EON, EOR, ORR, MVN, ORN
		op = 3
	}
	tok := p.next()
	str := tok.String()
	var count int16
	switch tok.ScanToken {

of memory. Because C.malloc cannot fail, it has no two-result form
that returns errno.

# C references to Go

Go functions can be exported for use by C code in the following way:

	//export MyFunction
	func MyFunction(arg1, arg2 int, arg3 string) int64 {...}

	//export MyFunction2
	func MyFunction2(arg1, arg2 int, arg3 string) (int64, *C.char) {...}

func (p *parser) parseNumeric(b []byte) int64 {
	// Check for base-256 (binary) format first.
	// If the first bit is set, then all following bits constitute a two's
	// complement encoded number in big-endian byte order.
	if len(b) > 0 && b[0]&0x80 != 0 {
		// Handling negative numbers relies on the following identity:
		//	-a-1 == ^a
		//
		// If the number is negative, we use an inversion mask to invert the

	Devminor int64 // Minor device number (valid for TypeChar or TypeBlock)

	// Xattrs stores extended attributes as PAX records under the
	// "SCHILY.xattr." namespace.
	//
	// The following are semantically equivalent:
	//  h.Xattrs[key] = value
	//  h.PAXRecords["SCHILY.xattr."+key] = value
	//
	// When Writer.WriteHeader is called, the contents of Xattrs will take
	// precedence over those in PAXRecords.

		tf := fmt.Sprintf("/proc/%s/status", f.Name())
		d, err := os.ReadFile(tf)
		if err != nil {
			// There are a surprising number of ways this
			// can error out on linux.  We've seen all of
			// the following, so treat any error here as
			// equivalent to the "process is gone":
			//    os.IsNotExist(err),
			//    "... : no such process",
			//    "... : bad file descriptor.
			continue
		}

			PAXRecords: map[string]string{
				"linkpath": "PAX4/PAX4/long-linkpath-name",
			},
			Format: FormatPAX,
		}},
	}, {
		// Both BSD and GNU tar truncate long names at first NUL even
		// if there is data following that NUL character.
		// This is reasonable as GNU long names are C-strings.
		file: "testdata/gnu-long-nul.tar",
		headers: []*Header{{
			Name:     "0123456789",
			Mode:     0644,
			Uid:      1000,