directory-per-package step 1: move files from lib/X.go to lib/X/X.go

no substantive changes except:
	- new Makefiles, all auto-generated
	- go/src/lib/Makefile has been extensively edited

R=rsc
OCL=28310
CL=28310

1 files changed, 228 insertions, 0 deletions

diff --git a/src/lib/exec/exec.go b/src/lib/exec/exec.go
new file mode 100644
index 000000000..c13bad3e0
--- /dev/null
+++ b/src/lib/exec/exec.go
@@ -0,0 +1,228 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The exec package runs external commands.
+package exec
+
+import (
+	"os";
+	"strings";
+)
+
+// Arguments to Run.
+const (
+	DevNull = iota;
+	PassThrough;
+	Pipe;
+	MergeWithStdout;
+)
+
+// A Cmd represents a running command.
+// Stdin, Stdout, and Stderr are Files representing pipes
+// connected to the running command's standard input, output, and error,
+// or else nil, depending on the arguments to Run.
+// Pid is the running command's operating system process ID.
+type Cmd struct {
+	Stdin *os.File;
+	Stdout *os.File;
+	Stderr *os.File;
+	Pid int;
+}
+
+// Given mode (DevNull, etc), return file for child
+// and file to record in Cmd structure.
+func modeToFiles(mode, fd int) (*os.File, *os.File, os.Error) {
+	switch mode {
+	case DevNull:
+		rw := os.O_WRONLY;
+		if fd == 0 {
+			rw = os.O_RDONLY;
+		}
+		f, err := os.Open("/dev/null", rw, 0);
+		return f, nil, err;
+	case PassThrough:
+		switch fd {
+		case 0:
+			return os.Stdin, nil, nil;
+		case 1:
+			return os.Stdout, nil, nil;
+		case 2:
+			return os.Stderr, nil, nil;
+		}
+	case Pipe:
+		r, w, err := os.Pipe();
+		if err != nil {
+			return nil, nil, err;
+		}
+		if fd == 0 {
+			return r, w, nil;
+		}
+		return w, r, nil;
+	}
+	return nil, nil, os.EINVAL;
+}
+
+// Run starts the binary prog running with
+// arguments argv and environment envv.
+// It returns a pointer to a new Cmd representing
+// the command or an error.
+//
+// The parameters stdin, stdout, and stderr
+// specify how to handle standard input, output, and error.
+// The choices are DevNull (connect to /dev/null),
+// PassThrough (connect to the current process's standard stream),
+// Pipe (connect to an operating system pipe), and
+// MergeWithStdout (only for standard error; use the same
+// file descriptor as was used for standard output).
+// If a parameter is Pipe, then the corresponding field (Stdin, Stdout, Stderr)
+// of the returned Cmd is the other end of the pipe.
+// Otherwise the field in Cmd is nil.
+func Run(argv0 string, argv, envv []string, stdin, stdout, stderr int) (p *Cmd, err os.Error)
+{
+	p = new(Cmd);
+	var fd [3]*os.File;
+
+	if fd[0], p.Stdin, err = modeToFiles(stdin, 0); err != nil {
+		goto Error;
+	}
+	if fd[1], p.Stdout, err = modeToFiles(stdout, 1); err != nil {
+		goto Error;
+	}
+	if stderr == MergeWithStdout {
+		p.Stderr = p.Stdout;
+	} else if fd[2], p.Stderr, err = modeToFiles(stderr, 2); err != nil {
+		goto Error;
+	}
+
+	// Run command.
+	p.Pid, err = os.ForkExec(argv0, argv, envv, &fd);
+	if err != nil {
+		goto Error;
+	}
+	if fd[0] != os.Stdin {
+		fd[0].Close();
+	}
+	if fd[1] != os.Stdout {
+		fd[1].Close();
+	}
+	if fd[2] != os.Stderr && fd[2] != fd[1] {
+		fd[2].Close();
+	}
+	return p, nil;
+
+Error:
+	if fd[0] != os.Stdin && fd[0] != nil {
+		fd[0].Close();
+	}
+	if fd[1] != os.Stdout && fd[1] != nil {
+		fd[1].Close();
+	}
+	if fd[2] != os.Stderr && fd[2] != nil && fd[2] != fd[1] {
+		fd[2].Close();
+	}
+	if p.Stdin != nil {
+		p.Stdin.Close();
+	}
+	if p.Stdout != nil {
+		p.Stdout.Close();
+	}
+	if p.Stderr != nil {
+		p.Stderr.Close();
+	}
+	return nil, err;
+}
+
+// Wait waits for the running command p,
+// returning the Waitmsg returned by os.Wait and an error.
+// The options are passed through to os.Wait.
+// Setting options to 0 waits for p to exit;
+// other options cause Wait to return for other
+// process events; see package os for details.
+func (p *Cmd) Wait(options uint64) (*os.Waitmsg, os.Error) {
+	if p.Pid < 0 {
+		return nil, os.EINVAL;
+	}
+	w, err := os.Wait(p.Pid, options);
+	if w != nil && (w.Exited() || w.Signaled()) {
+		p.Pid = -1;
+	}
+	return w, err;
+}
+
+// Close waits for the running command p to exit,
+// if it hasn't already, and then closes the non-nil file descriptors
+// p.Stdin, p.Stdout, and p.Stderr.
+func (p *Cmd) Close() os.Error {
+	if p.Pid >= 0 {
+		// Loop on interrupt, but
+		// ignore other errors -- maybe
+		// caller has already waited for pid.
+		w, err := p.Wait(0);
+		for err == os.EINTR {
+			w, err = p.Wait(0);
+		}
+	}
+
+	// Close the FDs that are still open.
+	var err os.Error;
+	if p.Stdin != nil && p.Stdin.Fd() >= 0 {
+		if err1 := p.Stdin.Close(); err1 != nil {
+			err = err1;
+		}
+	}
+	if p.Stdout != nil && p.Stdout.Fd() >= 0 {
+		if err1 := p.Stdout.Close(); err1 != nil && err != nil {
+			err = err1;
+		}
+	}
+	if p.Stderr != nil && p.Stderr != p.Stdout && p.Stderr.Fd() >= 0 {
+		if err1 := p.Stderr.Close(); err1 != nil && err != nil {
+			err = err1;
+		}
+	}
+	return err;
+}
+
+func canExec(file string) bool{
+	d, err := os.Stat(file);
+	if err != nil {
+		return false;
+	}
+	return d.IsRegular() && d.Permission() & 0111 != 0;
+}
+
+// LookPath searches for an executable binary named file
+// in the directories named by the PATH environment variable.
+// If file contains a slash, it is tried directly and the PATH is not consulted.
+//
+// TODO(rsc): Does LookPath belong in os instead?
+func LookPath(file string) (string, os.Error) {
+	// NOTE(rsc): I wish we could use the Plan 9 behavior here
+	// (only bypass the path if file begins with / or ./ or ../)
+	// but that would not match all the Unix shells.
+
+	if strings.Index(file, "/") >= 0 {
+		if canExec(file) {
+			return file, nil;
+		}
+		return "", os.ENOENT;
+	}
+	pathenv, err := os.Getenv("PATH");
+	if err != nil {
+		// Unix shell semantics: no $PATH means assume PATH=""
+		// (equivalent to PATH=".").
+		pathenv = "";
+	}
+	for i, dir := range strings.Split(pathenv, ":") {
+		if dir == "" {
+			// Unix shell semantics: path element "" means "."
+			dir = ".";
+		}
+		if canExec(dir+"/"+file) {
+			return dir+"/"+file, nil;
+		}
+	}
+	return "", os.ENOENT;
+}
+