if b.err != nil {
		return b.err
	}
	if b.Available() <= 0 && b.Flush() != nil {
		return b.err
	}
	b.buf[b.n] = c
	b.n++
	return nil
}

// WriteRune writes a single Unicode code point, returning
// the number of bytes written and any error.
func (b *Writer) WriteRune(r rune) (size int, err error) {
	// Compare as uint32 to correctly handle negative runes.
	if uint32(r) < utf8.RuneSelf {

</p>

<p>
For example, in this program:
</p>

<pre>
var a string

func f() {
	print(a)
}

func hello() {
	a = "hello, world"
	go f()
}
</pre>

<p>
calling <code>hello</code> will print <code>"hello, world"</code>
at some point in the future (perhaps after <code>hello</code> has returned).
</p>

<h3 id="goexit">Goroutine destruction</h3>

<p>

	flag.Var(&I, "I", "include directory; can be set multiple times")
	flag.BoolVar(&DebugV, "v", false, "print debug output")
	flag.Var(objabi.NewDebugFlag(&DebugFlags, nil), "d", "enable debugging settings; try -d help")
	objabi.AddVersionFlag() // -V
	objabi.Flagcount("S", "print assembly and machine code", &PrintOut)
}

// MultiFlag allows setting a value multiple times to collect a list, as in -I=dir1 -I=dir2.

	return exec.Command("security", "cms", "-D", "-i", string(fname))
}

func plistExtract(fname string, path string) ([]byte, error) {
	out, err := exec.Command("/usr/libexec/PlistBuddy", "-c", "Print "+path, fname).CombinedOutput()
	if err != nil {
		return nil, err
	}
	return bytes.TrimSpace(out), nil
}

func getLines(cmd *exec.Cmd) [][]byte {
	out := output(cmd)

		Can be repeated to define multiple symbols.
	-I dir1 -I dir2
		Search for #include files in dir1, dir2, etc,
		after consulting $GOROOT/pkg/$GOOS_$GOARCH.
	-S
		Print assembly and machine code.
	-V
		Print assembler version and exit.
	-debug
		Dump instructions as they are parsed.
	-dynlink
		Support references to Go symbols defined in other shared libraries.
	-e

On Windows, [EvalSymlinks] no longer evaluates mount points,
which was a source of many inconsistencies and bugs.
This behavior is controlled by the `winsymlink` setting.
For Go 1.23, it defaults to `winsymlink=1`.
Previous versions default to `winsymlink=0`.

On Windows, [EvalSymlinks] no longer tries to normalize
volumes to drive letters, which was not always even possible.
This behavior is controlled by the `winreadlinkvolume` setting.

rfork n

if(! test -f make.rc){
	echo 'all.rc must be run from $GOROOT/src' >[1=2]
	exit wrongdir
}

. ./make.rc --no-banner $*
bind -b $GOROOT/bin /bin
./run.rc --no-rebuild

and then replaces each occurrence of a type C.xxx with _C_xxx.

If xxx is data, cgo arranges for C.xxx to refer to the C variable,
with the type translated as described above.  To do this, cgo must
introduce a Go variable that points at the C variable (the linker can
be told to initialize this pointer).  For example, if the gmp library
provided

	mpz_t zero;

then cgo would rewrite a reference to C.zero by introducing

	var _C_zero *C.mpz_t

				// An "unfortunate" case: the feature was once
				// included in the API (e.g. go1.txt), but was
				// subsequently removed. These are already
				// acknowledged by being in the file
				// "api/except.txt". No need to print them out
				// here.
			} else if portRemoved(feature) {
				// okay.
			} else if featureSet[featureWithoutContext(feature)] {
				// okay.
			} else {
				fmt.Fprintf(w, "-%s\n", feature)

On Windows, the mode bits reported by [Lstat] and [Stat] for
reparse points changed. Mount points no longer have [ModeSymlink] set,
and reparse points that are not symlinks, Unix sockets, or dedup files
now always have [ModeIrregular] set.
This behavior is controlled by the `winsymlink` setting.
For Go 1.23, it defaults to `winsymlink=1`.