os: StartProcess doesn't pass the arguments

[Litarvan]

I tried everything, but os.StartProcess seems to not pass the given arguments

What version of Go are you using (go version)?

go version go1.9.2 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

$ go env
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/litarvan/go"
GORACE=""
GOROOT="/usr/lib/go"
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build281376345=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

test_executable :

#!/bin/bash
echo Args are : $@

main.go :

package main

import (
	"os"
)

func main() {
	stdout, _ := os.Create("stdout.log")
	stderr, _ := os.Create( "stderr.log")
	
	processPath := "test_executable"
	args := "a_random_arg"
	
	println("Starting : " + processPath + " " + args)
	process, err := os.StartProcess(processPath, []string {args}, &os.ProcAttr{ Dir: ".", Files: []*os.File{stderr, stdout} })
	
	if err != nil {
		println(err.Error())
		return
	}
	
	process.Wait()
}

What did you expect to see?

Output should be : Starting : test_executable a_random_arg
stdout.log should contain : Args are : a_random_arg, as it shows when i'm copy pasting the command test_executable a_random_arg in my terminal

What did you see instead?

Output is : Starting : test_executable a_random_arg
stdout.log contains : Args are :, there is no args given

[davecheney]

Thank you for raising this issue. Unlike many projects on GitHub, the Go project does not use its bug tracker for general discussion or asking questions. We only use our bug tracker for tracking bugs and tracking proposals going through the Proposal Process.

Please see https://golang.org/wiki/Questions for good places to ask questions.

[Litarvan]

It looks like at first, but the big code pasting is not my program, but a proof of the bug.
This is not a question, but an issue in the os.StartProcess function, it is an issue, no ?

[bradfitz]

For https://golang.org/pkg/os/#StartProcess, your argv must contain the binary name first, before the "actual" arguments.

But really nobody should use os.StartProcess. You should use the os/exec package instead.

[Litarvan]

Oh, thanks ! But, shouldn't this be written in the os.StartProcess doc ?

[bradfitz]

Well, it does say:

StartProcess is a low-level interface.

And I guess people familiar with the low-level interface know the meaning of argv and that it includes the name of the process as it was invoked.

But sure, I'll send a change with a bit of docs.

[Litarvan]

Guess it's my bad, i only looked at the in-code doc, and i'm new to low-level programming, thanks tho !

[gopherbot]

Change https://golang.org/cl/85675 mentions this issue: os: document that StartProcess's argv starts with the binary name

[bradfitz]

No worries. I sent https://go-review.googlesource.com/#/c/go/+/85675

[davecheney]

As Brad mentioned, you probably don’t want to use this low level interface. Try https://golang.org/pkg/os/exec/#Cmd

…

On 29 Dec 2017, at 12:15, Adrien Navratil ***@***.***> wrote: Guess it's my bad, i only looked at the in-code doc, and i'm new to low-level programming, thanks tho ! — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub, or mute the thread.

[Litarvan]

I managed to do it using this, thanks !