can't exec command with spaces about script

[shumin1027]

This is how I solve this problem：

package shell

import (
	"bytes"
	"github.com/bitfield/script"
	"os/exec"
)

type PipeWrap struct {
	*script.Pipe
}

func (p *PipeWrap) ToPipe(s string) *script.Pipe {
	return p.Pipe
}

func (p *PipeWrap) Exec(s string) *script.Pipe {
	if p == nil || p.Error() != nil {
		return p.Pipe
	}
	q := NewPipeWrap()
	//args := strings.Fields(s)
	cmd := exec.Command("bash", "-c", s)
	cmd.Stdin = p.Reader
	output, err := cmd.CombinedOutput()
	if err != nil {
		q.SetError(err)
	}
	return q.WithReader(bytes.NewReader(output))
}
func NewPipeWrap() *PipeWrap {
	PipeWrap := new(PipeWrap)
	PipeWrap.Pipe = script.NewPipe()
	return PipeWrap
}

func Exec(s string) *script.Pipe {
	return NewPipeWrap().Exec(s)
}

[posener]

The right solution for this problem is to change the API of Exec to a (string, ...string), exactly as the exec.Command API is, and pass it as is to the exec.Command call.

[bitfield]

That's actually a little bit of a pain, which is one reason why we wrap exec.Command to be able to pass it a single string.

[bitfield]

Thanks for the report @shumin1027! PR welcome, from anyone who wants to tackle this.

[posener]

That's actually a little bit of a pain, which is one reason why we wrap exec.Command to be able to pass it a single string.

I'm not sure I fully understand what is the pain point. Having the input as a single string?

[bitfield]

Yes, exec.Command takes a string and a slice of strings as the command line. In shell scripts we can simply write this as one string, so script replicates this.

[posener]

Right, but then you can't have a single argument which is composed of multiple words...

…

On Mon, Oct 28, 2019 at 3:34 PM John Arundel ***@***.***> wrote: Yes, exec.Command takes a string and a slice of strings as the command line. In shell scripts we can simply write this as one string, so script replicates this. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#32?email_source=notifications&email_token=AAHAN7SAWUKZEEIB4EQP2FLQQ3S5TA5CNFSM4I64L7U2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOECM4GUI#issuecomment-546947921>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAHAN7XMRJIO22JPO5XTNGDQQ3S5TANCNFSM4I64L7UQ> .

[bitfield]

Unless you quote it, of course, which is what this issue is really about.

[posener]

Quoting does not help: The input string is passed to strings.Field, which is passed to the exec.Command in the next line.

Unfortunately, the strings.Fields does not group into a single field quoted words:

fmt.Println(strings.Join(strings.Fields(`a b "c d" e`), ", "))
// Output: a, b, "c, d", e

Notice that in this example, "c is one string returned from strings.Fields and d" is another, while for the command.Exec you would want c d as a single string.

[NightMachinery]

@shumin1027 commented on Oct 10, 2019, 4:35 AM GMT+3:30:

This is how I solve this problem：

package shell

import (
	"bytes"
	"github.com/bitfield/script"
	"os/exec"
)

type PipeWrap struct {
	*script.Pipe
}

func (p *PipeWrap) ToPipe(s string) *script.Pipe {
	return p.Pipe
}

func (p *PipeWrap) Exec(s string) *script.Pipe {
	if p == nil || p.Error() != nil {
		return p.Pipe
	}
	q := NewPipeWrap()
	//args := strings.Fields(s)
	cmd := exec.Command("bash", "-c", s)
	cmd.Stdin = p.Reader
	output, err := cmd.CombinedOutput()
	if err != nil {
		q.SetError(err)
	}
	return q.WithReader(bytes.NewReader(output))
}
func NewPipeWrap() *PipeWrap {
	PipeWrap := new(PipeWrap)
	PipeWrap.Pipe = script.NewPipe()
	return PipeWrap
}

func Exec(s string) *script.Pipe {
	return NewPipeWrap().Exec(s)
}

I'm new to go, but I guess there is no way to make that custom Exec method work in the middle of a pipe? (Because all functions in the library return script.Pipe, which we can't add an extension method to.)

[shumin1027]

@shumin1027 commented on Oct 10, 2019, 4:35 AM GMT+3:30:

This is how I solve this problem：

package shell

import (
	"bytes"
	"github.com/bitfield/script"
	"os/exec"
)

type PipeWrap struct {
	*script.Pipe
}

func (p *PipeWrap) ToPipe(s string) *script.Pipe {
	return p.Pipe
}

func (p *PipeWrap) Exec(s string) *script.Pipe {
	if p == nil || p.Error() != nil {
		return p.Pipe
	}
	q := NewPipeWrap()
	//args := strings.Fields(s)
	cmd := exec.Command("bash", "-c", s)
	cmd.Stdin = p.Reader
	output, err := cmd.CombinedOutput()
	if err != nil {
		q.SetError(err)
	}
	return q.WithReader(bytes.NewReader(output))
}
func NewPipeWrap() *PipeWrap {
	PipeWrap := new(PipeWrap)
	PipeWrap.Pipe = script.NewPipe()
	return PipeWrap
}

func Exec(s string) *script.Pipe {
	return NewPipeWrap().Exec(s)
}

I'm new to go, but I guess there is no way to make that custom Exec method work in the middle of a pipe? (Because all functions in the library return script.Pipe, which we can't add an extension method to.)

This issue seems to have been fixed Fix Exec to handle quotes #42
example : https://github.com/bitfield/script/blob/master/examples/execute/main.go

[bitfield]

That would explain why it's closed...