code review 4517134: exec: add Cmd methods StdinPipe, StdoutPipe, StderrPipe

exec: add Cmd methods StdinPipe, StdoutPipe, StderrPipe

It gets annoying to do this in caller code otherwise,
especially having to remember to Close one side.

[bradfitz, 2011-06-02 15:35:15]

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

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

[rsc, 2011-06-02 15:39:00]

http://codereview.appspot.com/4517134/diff/5001/src/pkg/exec/exec.go
File src/pkg/exec/exec.go (right):

http://codereview.appspot.com/4517134/diff/5001/src/pkg/exec/exec.go#newcode286
src/pkg/exec/exec.go:286: // StdinPipe creates a pipe hooked up to the Cmd's
Stdin and returns
// StdinPipe returns a pipe that will be connected to the command's
// standard input when the command starts.

etc

http://codereview.appspot.com/4517134/diff/5001/src/pkg/exec/exec.go#newcode303
src/pkg/exec/exec.go:303: func (c *Cmd) StdoutPipe() (io.Reader, os.Error) {
might as well be a ReadCloser
same for the one below
or add to c.closeAfterWait

[rsc, 2011-06-02 15:39:50]

exec: add Cmd methods StdinPipe, StdoutPipe, StderrPipe

avoiding {,} shorthands makes grep more useful

[bradfitz, 2011-06-02 17:12:41]

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

Please take another look.

[bradfitz, 2011-06-02 17:13:12]

http://codereview.appspot.com/4517134/diff/5001/src/pkg/exec/exec.go
File src/pkg/exec/exec.go (right):

http://codereview.appspot.com/4517134/diff/5001/src/pkg/exec/exec.go#newcode286
src/pkg/exec/exec.go:286: // StdinPipe creates a pipe hooked up to the Cmd's
Stdin and returns
On 2011/06/02 15:39:01, rsc wrote:
> // StdinPipe returns a pipe that will be connected to the command's
> // standard input when the command starts.
> 
> etc

Done.

http://codereview.appspot.com/4517134/diff/5001/src/pkg/exec/exec.go#newcode303
src/pkg/exec/exec.go:303: func (c *Cmd) StdoutPipe() (io.Reader, os.Error) {
On 2011/06/02 15:39:01, rsc wrote:
> might as well be a ReadCloser
> same for the one below
> or add to c.closeAfterWait

I see no reason to let people close it themselves (though curious to hear use
cases), so added to closeAfterWait.

[rsc, 2011-06-02 17:15:37]

LGTM

http://codereview.appspot.com/4517134/diff/11001/src/pkg/exec/exec.go
File src/pkg/exec/exec.go (right):

http://codereview.appspot.com/4517134/diff/11001/src/pkg/exec/exec.go#newcode316
src/pkg/exec/exec.go:316: }
if c.process != nil {
    return nil, os.NewError("exec: StdinPipe after process started")
}
etc

[bradfitz, 2011-06-02 17:17:30]

http://codereview.appspot.com/4517134/diff/11001/src/pkg/exec/exec.go
File src/pkg/exec/exec.go (right):

http://codereview.appspot.com/4517134/diff/11001/src/pkg/exec/exec.go#newcode316
src/pkg/exec/exec.go:316: }
On 2011/06/02 17:15:37, rsc wrote:
> if c.process != nil {
>     return nil, os.NewError("exec: StdinPipe after process started")
> }
> etc
> 

Done.

[bradfitz, 2011-06-02 17:26:12]

*** Submitted as http://code.google.com/p/go/source/detail?r=7a1ae1f1a7df ***

exec: add Cmd methods StdinPipe, StdoutPipe, StderrPipe

It gets annoying to do this in caller code otherwise,
especially having to remember to Close one side.

R=rsc
CC=golang-dev
http://codereview.appspot.com/4517134