No working directory for sh.Exec

[corebreaker]

Hello,

os/exec.Command allow a working directory, but sometimes, we need it in sh.Exec too.

The easy way is to use the exec.Command function, but i don't like it.

I propose to pass a special variable in env parameter, like this:

Exec(map[string]string { "#CWD": "/home/theUser/mydir" }, nil, nil, "my-command")

[natefinch]

I think this is a valid concern and I think there is a way to address it. But the linked PR was not the right solution. I think we can come up with something better and more intuitive.

[corebreaker]

ok, so i'll propose another PR.

[philipsahli]

If have added the PR #246, which should solve this issue. I need to run commands with mage/sh in the working directory, so I pass the variable #CWD with the value from os.Getenv("PWD") to sh.RunWith.

[corebreaker]

Great !

[sluedecke]

I currently use this function as a workaround:

func runCommand(cwd string, command string, args ...string) (ran bool, err error) {
	wd, _ := os.Getwd()
	err = os.Chdir(cwd)
	if err != nil {
		return false, err
	}
	ran, err = sh.Exec(map[string]string{"#CWD": cwd}, os.Stdout, os.Stderr, command, args...)
	os.Chdir(wd) // can return an error, but should never happen.  Smart coders might want to handle it anyways
	return ran, err
}

[waj334]

I currently use this function as a workaround:

func runCommand(cwd string, command string, args ...string) (ran bool, err error) {
	wd, _ := os.Getwd()
	err = os.Chdir(cwd)
	if err != nil {
		return false, err
	}
	ran, err = sh.Exec(map[string]string{"#CWD": cwd}, os.Stdout, os.Stderr, command, args...)
	os.Chdir(wd) // can return an error, but should never happen.  Smart coders might want to handle it anyways
	return ran, err
}

This could cause some commands that run in parallel to fail

[jcchavezs]

I think sh.Exec should have a way to pass the directory. For example, in Coraza we run go test ./... in /my-folder and then go test ./... in /my-folder/my-subfolder (see https://github.com/corazawaf/coraza/pull/422/files#diff-520109d035a196d29d0a86e9c4e6c98e98abf056141b84df68c0d48167b87b25R83) and there is no way to pass a global working directory.
cc @anuraaga as he usually have good ideas on how to overcome API challenges.

[hamzaelsaawy]

Is there any consensus on this?
I created #444 to create a struct to allow setting the different options in a struct, but I can update it to use options instead, as mentioned in #307.

[ivanduka]

I currently use this function as a workaround:

func runCommand(cwd string, command string, args ...string) (ran bool, err error) {
	wd, _ := os.Getwd()
	err = os.Chdir(cwd)
	if err != nil {
		return false, err
	}
	ran, err = sh.Exec(map[string]string{"#CWD": cwd}, os.Stdout, os.Stderr, command, args...)
	os.Chdir(wd) // can return an error, but should never happen.  Smart coders might want to handle it anyways
	return ran, err
}

This could cause some commands that run in parallel to fail

This is a great workaround, I added a mutex call like this in front of the function and everything works fine except now everything is sequential in execution:

var mu sync.Mutex

func runInFolder(cwd string, command string, args ...string) error {
	mu.Lock()
	defer mu.Unlock()

	fmt.Printf("Running %q with %#v in %q\n", command, args, cwd)

	wd, err := os.Getwd()
	if err != nil {
		return err
	}

	err = os.Chdir(cwd)
	if err != nil {
		return err
	}

	output, err := sh.Output(command, args...)
	if err != nil {
		return err
	}

	fmt.Println(output)

	err = os.Chdir(wd)
	if err != nil {
		return err
	}

	return nil
}