github.com/gaukas/wazerofs@v0.1.0/sysfs/futimens_linux.go (about)

     1  package sysfs
     2  
     3  import (
     4  	"syscall"
     5  	"unsafe"
     6  	_ "unsafe"
     7  
     8  	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
     9  )
    10  
    11  const (
    12  	_AT_FDCWD   = -0x64
    13  	_UTIME_OMIT = (1 << 30) - 2
    14  )
    15  
    16  func utimens(path string, atim, mtim int64) experimentalsys.Errno {
    17  	times := timesToTimespecs(atim, mtim)
    18  	if times == nil {
    19  		return 0
    20  	}
    21  
    22  	var flags int
    23  	var _p0 *byte
    24  	_p0, err := syscall.BytePtrFromString(path)
    25  	if err == nil {
    26  		err = utimensat(_AT_FDCWD, uintptr(unsafe.Pointer(_p0)), times, flags)
    27  	}
    28  	return experimentalsys.UnwrapOSError(err)
    29  }
    30  
    31  // On linux, implement futimens via utimensat with the NUL path.
    32  func futimens(fd uintptr, atim, mtim int64) experimentalsys.Errno {
    33  	times := timesToTimespecs(atim, mtim)
    34  	if times == nil {
    35  		return 0
    36  	}
    37  	return experimentalsys.UnwrapOSError(utimensat(int(fd), 0 /* NUL */, times, 0))
    38  }
    39  
    40  // utimensat is like syscall.utimensat special-cased to accept a NUL string for the path value.
    41  func utimensat(dirfd int, strPtr uintptr, times *[2]syscall.Timespec, flags int) (err error) {
    42  	_, _, e1 := syscall.Syscall6(syscall.SYS_UTIMENSAT, uintptr(dirfd), strPtr, uintptr(unsafe.Pointer(times)), uintptr(flags), 0, 0)
    43  	if e1 != 0 {
    44  		err = e1
    45  	}
    46  	return
    47  }