xattr.Getxattr always returns empty string

[bitcartel]

Hi,

Using Mac OS X 10.7.3 and Go 1

From the example and my own tests, both writing and deleting a key-value pair succeeds (confirmed with /usr/bin/xattr).

However, Getxattr always returns an empty value.

value, _ := xattr.Getxattr(file, name)

Thanks.

[davecheney]

You are consuming the error, can you please try again and print the error if not nil, it may give us a clue what is going on.

On 10/04/2012, at 14:08, bitcartelreply@reply.github.com wrote:

Hi,

Using Mac OS X 10.7.3 and Go 1

From the example and my own tests, both writing and deleting a key-value pair succeeds (confirmed with /usr/bin/xattr).

However, Getxattr always returns an empty value.

value, _ := xattr.Getxattr(file, name)

Thanks.

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[bitcartel]

value, myerr := xattr.Getxattr(file, name)
fmt.Printf("value = %s\n", value)
fmt.Printf("err = %s\n",myerr)

results in:

value =
err = getxattr testfile username: errno 0

On 4/9/12 9:14 PM, Dave Cheney wrote:

You are consuming the error, can you please try again and print the error if not nil, it may give us a clue what is going on.

On 10/04/2012, at 14:08, bitcartelreply@reply.github.com wrote:

Hi,

Using Mac OS X 10.7.3 and Go 1

From the example and my own tests, both writing and deleting a key-value pair succeeds (confirmed with /usr/bin/xattr).

However, Getxattr always returns an empty value.

value, _ := xattr.Getxattr(file, name)

Thanks.

---

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[davecheney]

Thanks, I'll take a look this evening. For comparison could you post the output of xattr.

On 10/04/2012, at 14:43, bitcartelreply@reply.github.com wrote:

value, myerr := xattr.Getxattr(file, name)
fmt.Printf("value = %s\n", value)
fmt.Printf("err = %s\n",myerr)

results in:

value =
err = getxattr testfile username: errno 0

On 4/9/12 9:14 PM, Dave Cheney wrote:

You are consuming the error, can you please try again and print the error if not nil, it may give us a clue what is going on.

On 10/04/2012, at 14:08, bitcartelreply@reply.github.com wrote:

Hi,

Using Mac OS X 10.7.3 and Go 1

From the example and my own tests, both writing and deleting a key-value pair succeeds (confirmed with /usr/bin/xattr).

However, Getxattr always returns an empty value.

value, _ := xattr.Getxattr(file, name)

Thanks.

---

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[bitcartel]

which xattr
/usr/bin/xattr

xattr -l testfile
username: dave

Thx.

On 4/9/12 9:54 PM, Dave Cheney wrote:

Thanks, I'll take a look this evening. For comparison could you post the output of xattr.

On 10/04/2012, at 14:43, bitcartelreply@reply.github.com wrote:

value, myerr := xattr.Getxattr(file, name)
fmt.Printf("value = %s\n", value)
fmt.Printf("err = %s\n",myerr)

results in:

value =
err = getxattr testfile username: errno 0

On 4/9/12 9:14 PM, Dave Cheney wrote:

You are consuming the error, can you please try again and print the error if not nil, it may give us a clue what is going on.

On 10/04/2012, at 14:08, bitcartelreply@reply.github.com wrote:

Hi,

Using Mac OS X 10.7.3 and Go 1

From the example and my own tests, both writing and deleting a key-value pair succeeds (confirmed with /usr/bin/xattr).

However, Getxattr always returns an empty value.

value, _ := xattr.Getxattr(file, name)

Thanks.

---

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[davecheney]

Hello, sorry I haven't replied yet, I hope to have some time to look at this issue on the weekend.

[bitcartel]

That's cool, thanks.

On 4/12/12 5:49 AM, Dave Cheney wrote:

Hello, sorry I haven't replied yet, I hope to have some time to look at this issue on the weekend.

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[kuba--]

..to fix this issue for darwin (macosx), you just need to consume Errno(0) in syscall_darwin.go

func getxattr(path string, name string, value *byte, size int, pos int, options int) (r int, e error) {
    if r0, _, e1 := syscall.Syscall6(syscall.SYS_GETXATTR, uintptr(unsafe.Pointer(syscall.StringBytePtr(path))), uintptr(unsafe.Pointer(syscall.StringBytePtr(name))), uintptr(unsafe.Pointer(value)), uintptr(size), uintptr(pos), uintptr(options)); e1 != syscall.Errno(0) {
        e = e1
    } else {
        r = int(r0)
    }
    return
}

[loop0]

I can confirm @kuba-- answer. You have to check for e1 != syscall.Errno(0) before returning it as error. I can make a pull request to fix this.

[avg-I]

Nudge. As it is the code won't work on darwin.
And a relevant documentation link, just in case: https://golang.org/pkg/syscall/#Errno

[kuba--]

@avg-I: two years ago I made some improvements in my repo: https://github.com/kuba--/xattr
and it works for me on darwin

[avg-I]

@kuba-- thank you for letting me know! I've created a pull request against your repo with a commit that adds freebsd support kuba--/xattr#1. The change should be applicable to this repo as well (modulo xattr_test.go).