code review 5675054: os/exec: add some examples

os/exec: add some examples

[bradfitz, 2012-02-15 02:34:34]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[adg, 2012-02-15 03:03:38]

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test.go
File src/pkg/os/exec/example_test.go (right):

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:17: path, err := exec.LookPath("xeyes")
bash? more like something someone would want to do

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:29: if err != nil {
if err := cmd.Run(); err != nil {

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:54: func ExampleCmd_StdoutPipe() {
This one you can put the expected output as a function comment.

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:68: var person P
var person struct {
..
}

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:69: err =
json.NewDecoder(stdout).Decode(&person)
if err := ... ; err != nil {

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:73: err = cmd.Wait()
if err := cmd.Wait(); err != nil {

[bradfitz, 2012-02-15 03:10:00]

Hello golang-dev@googlegroups.com, adg@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[r, 2012-02-15 03:10:20]

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test.go
File src/pkg/os/exec/example_test.go (right):

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:17: path, err := exec.LookPath("xeyes")
On 2012/02/15 03:03:38, adg wrote:
> bash? more like something someone would want to do

"go"

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:19: fmt.Printf("xeyes found at %s", path)
either add a newline or use Println

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:20: }
put in an err != nil case.
i like examples always to show good error-handling style, at least while we
still have errors

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:24: cmd := exec.Command("perl", "-npe",
"tr/a-z/A-Z/")
please no perl
how about
tr a-z A-Z

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:32: fmt.Printf("in all caps: %q", out.String())
again newline

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:40: fmt.Printf("It is currently %s", out)
again, newline
also currently means is.

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:44: cmd := exec.Command("perl", "-e", "sleep
5;")
sleep 5

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:49: log.Printf("Waiting for command to
finish...")
newline

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:51: log.Printf("Command finished with error:
%v", err)
newline

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:77: fmt.Printf("person is named %s and %d years
old", person.Name, person.Age)
newline

[bradfitzgoog, 2012-02-15 03:12:10]

adding newlines

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test.go
File src/pkg/os/exec/example_test.go (right):

http://codereview.appspot.com/5675054/diff/3001/src/pkg/os/exec/example_test....
src/pkg/os/exec/example_test.go:24: cmd := exec.Command("perl", "-npe",
"tr/a-z/A-Z/")
On 2012/02/15 03:10:21, r wrote:
> please no perl

you caught me

> how about
> tr a-z A-Z

[bradfitz, 2012-02-15 03:14:19]

Hello golang-dev@googlegroups.com, adg@golang.org, r@golang.org,
bradfitz@google.com (cc: golang-dev@googlegroups.com),

Please take another look.

[r, 2012-02-15 03:21:47]

LGTM

http://codereview.appspot.com/5675054/diff/7/src/pkg/os/exec/example_test.go
File src/pkg/os/exec/example_test.go (right):

http://codereview.appspot.com/5675054/diff/7/src/pkg/os/exec/example_test.go#...
src/pkg/os/exec/example_test.go:74: fmt.Printf("person is named %s and is %d
years old\n", person.Name, person.Age)
how about just
fmt.Printf("%s is %d years old\n", person.Name, person.Age)

[bradfitz, 2012-02-15 03:24:31]

*** Submitted as http://code.google.com/p/go/source/detail?r=2cd678dddab9 ***

os/exec: add some examples

R=golang-dev, adg, r, bradfitz
CC=golang-dev
http://codereview.appspot.com/5675054