x/sys/windows: missing GetFileTime function on Windows #21541

skillian · 2017-08-19T22:42:22Z

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

Go 1.8.3

Does this issue reproduce with the latest release?

I am able to reproduce this with Go 1.8.3 which seems to be the latest stable version available from golang.org.

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

Windows 10 on x86_64

Output of go env:

set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=D:\Users\spkillian@outlook.com\Dropbox\dev\go
set GORACE=
set GOROOT=C:\Go
set GOTOOLDIR=C:\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=C:\Users\SPKIL_~1\AppData\Local\Temp\go-build427541383=/tmp/go-build -gno-record-gcc-switches
set CXX=g++
set CGO_ENABLED=1
set PKG_CONFIG=pkg-config
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2

What did you do?

This is for a missing syscall function, so I suppose a minimum reproducible program would be:

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

package main

import (
    "fmt"
    "os"
    "syscall"
)

const (
    anyFile = "any_file.txt"
)

func main() {
    var creationTime syscall.Filetime
    var lastAccessTime syscall.Filetime
    var lastWriteTime syscall.Filetime

    utf16FileName, err := syscall.UTF16FromString(anyFile)
    if err != nil {
        fmt.Fprintf(os.Stderr, "Failed to convert string %q to UTF16: %v", anyFile, err)
    }

    err = syscall.GetFileTime(utf16FileName, &creationTime, &lastAccessTime, &lastWriteTime)
    if err != nil {
        fmt.Fprintf(os.Stderr, "Error getting FileTime of file %v: %v", anyFile, err)
        return
    }
    // do something with creationTime, lastAccessTime and/or lastWriteTime
    return
}

Go Playground

What did you expect to see?

syscall.GetFileName should be defined on Windows, like syscall.SetFileTime

What did you see instead?

PowerShell output:
github.com\skillian\getfiletime\expected.go:23: undefined: syscall.GetFileTime

The text was updated successfully, but these errors were encountered:

odeke-em · 2017-08-20T03:02:24Z

/cc @alexbrainman

skillian · 2017-08-20T20:04:00Z

My use case is that I have a simple grep-like program that also needs to include only files created within a date range. Sometimes the files are modified after they are created so using os.FileInfo.ModTime is not sufficient.

alexbrainman · 2017-08-21T01:32:32Z

@skillian, yes, syscall package does not have SetFileTime Windows API implemented. Unfortunately, we cannot add SetFileTime to syscall package - it has been decided to freeze syscall package. But we can add SetFileTime to golang.org/x/sys/windows package. In fact you can do it yourself - https://golang.org/doc/contribute.html is how to contribute to Go project. Would you like to do it yourself? If not, I or others will do it.

Alex

skillian · 2017-08-21T20:00:36Z

@alexbrainman Thank you for looking into this. I don't mean to be pedantic, but I want to clarify that I'm looking at adding syscall.GetFileTime because syscall.SetFileTime is in fact implemented by syscall currently (just tested in 1.8.3):

package main

import (
    "fmt"
    "os"
    "syscall"
)

func main() {
    filename := os.Args[1]

    handle, err := syscall.CreateFile(
        syscall.StringToUTF16Ptr(filename),
        syscall.FILE_WRITE_ATTRIBUTES,
        syscall.FILE_SHARE_READ | syscall.FILE_SHARE_WRITE | syscall.FILE_SHARE_DELETE,
        nil,
        syscall.OPEN_EXISTING,
        syscall.FILE_ATTRIBUTE_NORMAL,
        0)

    if err != nil {
        fmt.Fprintf(os.Stderr, "Error opening %q: %v", filename, err)
        return
    }

    defer syscall.CloseHandle(handle)

    ctime := syscall.Filetime{0x01020304, 0x05060708}
    atime := syscall.Filetime{0x090A0B0C, 0x0D0E0F10}
    mtime := syscall.Filetime{0x11121314, 0x15161718}

    err = syscall.SetFileTime(handle, &ctime, &atime, &mtime)

    if err != nil {
        fmt.Fprintf(os.Stderr, "Error setting file %q time: %v", filename, err)
    }
}

That being said, I understand what you mean about syscall being frozen and will instead try to put this into golang.org/x/sys/windows like you said.

I would love to contribute this myself and had begun following the directions on the contribute.html page you referenced, but I don't understand how the zsyscall_*.go files are emitted by go generate, so I don't know what I'd have to change to have go generate emit the code for GetFileTime (is it just by adding a signature in a sys comment like the other lines starting on line 83?) If you could tell me or tell me where I could look to figure that out myself, I'd be more than happy to do so.

EDIT: removed # from line number to remove link to Issue 83.

alexbrainman · 2017-08-22T07:04:25Z

I don't mean to be pedantic, but I want to clarify that I'm looking at adding syscall.GetFileTime because syscall.SetFileTime is in fact implemented by syscall currently

Correct. Sorry for confusing you. I made a mistake.

I understand what you mean about syscall being frozen and will instead try to put this into golang.org/x/sys/windows

Please do. That was what I was suggesting.

so I don't know what I'd have to change to have go generate emit the code for GetFileTime (is it just by adding a signature in a sys comment like the other lines starting on line 83?) If you could tell me or tell me where I could look to figure that out myself, I'd be more than happy to do so.

When you run "go generate" command, it looks for "//go:generate" string anywhere in your source files in the current directory:

$ pwd
/home/a/src/golang.org/x/sys/windows
$ grep //go:generate * -n
syscall_windows.go:17://go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go eventlog.go service.go syscall_windows.go security_windows.go
$

and then "go generate" command executes whatever command it finds. So in golang.org/x/sys/windows it will run

go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go eventlog.go service.go syscall_windows.go security_windows.go

You can see what $GOROOT/src/syscall/mksyscall_windows.go program do. But it looks for lines starting with "//sys", and generates syscalls for each line and output them all into zsyscall_windows.go. For example, this:

$ grep ^//sys.*SetFileTime * -n
syscall_windows.go:139://sys    SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
$

is what "//sys" line for SetFileTime looks like. You should add similar line for GetFileTime and run "go generate", and that should do it.

You can even do it in your own package, for example github.com/alexbrainman/winapi
But feel free to update golang.org/x/sys/windows if you like.

Alex

cobolbaby · 2018-12-20T06:21:10Z

import (
	"log"
	"syscall"
	"time"
)

func main() {

	ctime := time.Now()
	err := Chtimes("C:\\Users\\dev\\Desktop\\test2.zip", ctime, ctime, ctime)
	if err != nil {
		log.Fatal(err)
	}
}

// Chtimes changes the access and modification times of the named
// file, similar to the Unix utime() or utimes() functions.
//
// The underlying filesystem may truncate or round the values to a
// less precise time unit.
// If there is an error, it will be of type *PathError.
func Chtimes(name string, ctime time.Time, atime time.Time, mtime time.Time) error {
	var utimes [3]syscall.Timespec
	utimes[0] = syscall.NsecToTimespec(atime.UnixNano())
	utimes[1] = syscall.NsecToTimespec(mtime.UnixNano())
	utimes[2] = syscall.NsecToTimespec(ctime.UnixNano())
	if e := UtimesNano(name, utimes[0:]); e != nil {
		return e
	}
	return nil
}

func UtimesNano(path string, ts []syscall.Timespec) (err error) {
	if len(ts) != 3 {
		return syscall.EINVAL
	}
	pathp, e := syscall.UTF16PtrFromString(path)
	if e != nil {
		return e
	}
	h, e := syscall.CreateFile(pathp,
		syscall.FILE_WRITE_ATTRIBUTES, syscall.FILE_SHARE_WRITE, nil,
		syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
	if e != nil {
		return e
	}
	defer syscall.Close(h)
	a := syscall.NsecToFiletime(syscall.TimespecToNsec(ts[0]))
	w := syscall.NsecToFiletime(syscall.TimespecToNsec(ts[1]))
	c := syscall.NsecToFiletime(syscall.TimespecToNsec(ts[2]))
	return syscall.SetFileTime(h, &c, &a, &w)
}

iwdgo · 2021-12-12T12:04:12Z

Using the existing os.Stat() might solve the issue as it also returns the elements of GetFileTime().
The following code elements illustrate how to get ctime (creation time):

        fs, err := os.Stat(<file name>)
	if err != nil {
		// Error handling
		return
	}
	fsys := fs.Sys().(*syscall.Win32FileAttributeData)
        // fsys contains all values of syscall.GetFileAttributesEx()
        fsys.CreationTime
	fsys.LastAccessTime
	fsys.LastWriteTime // == fs.ModTime() after conversion
        // To get a time format, one method is:
        time.Unix(0, fsys.CreationTime.Nanoseconds()))

gopherbot · 2023-09-13T14:25:50Z

Change https://go.dev/cl/528015 mentions this issue: windows: add GetFileTime

odeke-em changed the title ~~Missing GetFileTime in syscall package~~ syscall/windows: missing GetFileTime function Aug 20, 2017

odeke-em changed the title ~~syscall/windows: missing GetFileTime function~~ syscall: missing GetFileTime function on Windows Aug 20, 2017

odeke-em added the OS-Windows label Aug 20, 2017

ianlancetaylor changed the title ~~syscall: missing GetFileTime function on Windows~~ x/sys/windows: missing GetFileTime function on Windows Mar 30, 2018

gopherbot added this to the Unreleased milestone Mar 30, 2018

ianlancetaylor added the NeedsFix The path to resolution is known, but the work has not been done. label Mar 30, 2018

ianlancetaylor modified the milestones: Unreleased, Unplanned Mar 30, 2018

gopherbot added the compiler/runtime Issues related to the Go compiler and/or runtime. label Jul 7, 2022

aisk mentioned this issue Sep 13, 2023

windows: add GetFileTime golang/sys#174

Closed

gopherbot closed this as completed in golang/sys@8ccaaf0 Oct 6, 2023

dagood mentioned this issue Jan 3, 2024

proposal: x/sys/windows: add various bcrypt.dll, crypt32.dll and ncrypt.dll functions #64819

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x/sys/windows: missing GetFileTime function on Windows #21541

x/sys/windows: missing GetFileTime function on Windows #21541

skillian commented Aug 19, 2017 •

edited

odeke-em commented Aug 20, 2017

skillian commented Aug 20, 2017

alexbrainman commented Aug 21, 2017

skillian commented Aug 21, 2017 •

edited

alexbrainman commented Aug 22, 2017

cobolbaby commented Dec 20, 2018

iwdgo commented Dec 12, 2021

gopherbot commented Sep 13, 2023

x/sys/windows: missing GetFileTime function on Windows #21541

x/sys/windows: missing GetFileTime function on Windows #21541

Comments

skillian commented Aug 19, 2017 • edited

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

Does this issue reproduce with the latest release?

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

What did you do?

What did you expect to see?

What did you see instead?

odeke-em commented Aug 20, 2017

skillian commented Aug 20, 2017

alexbrainman commented Aug 21, 2017

skillian commented Aug 21, 2017 • edited

alexbrainman commented Aug 22, 2017

cobolbaby commented Dec 20, 2018

iwdgo commented Dec 12, 2021

gopherbot commented Sep 13, 2023

skillian commented Aug 19, 2017 •

edited

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

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

skillian commented Aug 21, 2017 •

edited