return strconv.FormatInt(secs, 10)
	}

	// If seconds is negative, then perform correction.
	sign := ""
	if secs < 0 {
		sign = "-"             // Remember sign
		secs = -(secs + 1)     // Add a second to secs
		nsecs = -(nsecs - 1e9) // Take that second away from nsecs
	}
	return strings.TrimRight(fmt.Sprintf("%s%d.%09d", sign, secs, nsecs), "0")
}

// parsePAXRecord parses the input PAX record string into a key-value pair.

<code>package math</code>, which exports function <code>Sin</code>, and
installed the compiled package in the file identified by
<code>"lib/math"</code>.
This table illustrates how <code>Sin</code> is accessed in files
that import the package after the
various types of import declaration.
</p>

<pre class="grammar">
Import declaration          Local name of Sin

import   "lib/math"         math.Sin

	MOVQ	$runtime·profileloop1(SB), CX
	MOVQ	CX, 0(SP)
	CALL	runtime·externalthreadhandler(SB)
	RET
</pre>

<p>
In the general case, the frame size is followed by an argument size, separated by a minus sign.
(It's not a subtraction, just idiosyncratic syntax.)
The frame size <code>$24-8</code> states that the function has a 24-byte frame
and is called with 8 bytes of argument, which live on the caller's frame.

As a simple example, consider a package that uses cgo to call C.sin.
The following code will be generated by cgo:

	// compiled by gc

	//go:cgo_ldflag "-lm"

	type _Ctype_double float64

	//go:cgo_import_static _cgo_gcc_Cfunc_sin
	//go:linkname __cgo_gcc_Cfunc_sin _cgo_gcc_Cfunc_sin
	var __cgo_gcc_Cfunc_sin byte
	var _cgo_gcc_Cfunc_sin = unsafe.Pointer(&__cgo_gcc_Cfunc_sin)

		t.Errorf("zeroes: error=%v, want %v", err, ErrFormat)
	}

	// repeated directoryEndSignatures
	sig := make([]byte, 4)
	binary.LittleEndian.PutUint32(sig, directoryEndSignature)
	for i := 0; i < size-4; i += 4 {
		copy(b[i:i+4], sig)
	}
	_, err = NewReader(bytes.NewReader(b), size)
	if err != ErrFormat {
		t.Errorf("sigs: error=%v, want %v", err, ErrFormat)
	}

	// negative size

	x.doinit()
	y.doinit()
	z.doinit()
	C.mpz_tdiv_q(&z.i[0], &x.i[0], &y.i[0])
	return z
}

// Mod sets z = x % y and returns z.
// Like the result of the Go % operator, z has the same sign as x.
func (z *Int) Mod(x, y *Int) *Int {
	x.doinit()
	y.doinit()
	z.doinit()
	C.mpz_tdiv_r(&z.i[0], &x.i[0], &y.i[0])
	return z
}

// Lsh sets z = x << s and returns z.

		UncompressedSize64: 5678,
	}); err != nil {
		t.Fatal(err)
	}
	if err := w.Close(); err != nil {
		t.Fatal(err)
	}
	b := buf.Bytes()

	var sig [4]byte
	binary.LittleEndian.PutUint32(sig[:], uint32(fileHeaderSignature))

	idx := bytes.Index(b, sig[:])
	if idx == -1 {
		t.Fatal("file header not found")
	}
	b = b[idx:]

<code>package math</code>, which exports function <code>Sin</code>, and
installed the compiled package in the file identified by
<code>"lib/math"</code>.
This table illustrates how <code>Sin</code> is accessed in files
that import the package after the
various types of import declaration.
</p>

<pre class="grammar">
Import declaration          Local name of Sin

import   "lib/math"         math.Sin

func (f *File) findBodyOffset() (int64, error) {
	var buf [fileHeaderLen]byte
	if _, err := f.zipr.ReadAt(buf[:], f.headerOffset); err != nil {
		return 0, err
	}
	b := readBuf(buf[:])
	if sig := b.uint32(); sig != fileHeaderSignature {
		return 0, ErrFormat
	}
	b = b[22:] // skip over most of the header
	filenameLen := int(b.uint16())
	extraLen := int(b.uint16())

		return false
	}

	d = make([]byte, directory64EndLen)
	if _, err := zip.ReadAt(d, dirOff); err != nil {
		t.Fatalf("ReadAt(off=%d): %v", dirOff, err)
	}

	b := readBuf(d)
	if sig := b.uint32(); sig != directory64EndSignature {
		return false
	}

	size := b.uint64()
	if size != directory64EndLen-12 {
		t.Errorf("expected length of %d, got %d", directory64EndLen-12, size)
	}
	return true
}