at_libc.go

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build aix || solaris
     6  
     7  package unix
     8  
     9  import (
    10  	"syscall"
    11  	"unsafe"
    12  )
    13  
    14  //go:linkname procFstatat libc_fstatat
    15  //go:linkname procOpenat libc_openat
    16  //go:linkname procUnlinkat libc_unlinkat
    17  //go:linkname procReadlinkat libc_readlinkat
    18  //go:linkname procMkdirat libc_mkdirat
    19  
    20  var (
    21  	procFstatat,
    22  	procOpenat,
    23  	procUnlinkat,
    24  	procReadlinkat,
    25  	procMkdirat uintptr
    26  )
    27  
    28  func Unlinkat(dirfd int, path string, flags int) error {
    29  	p, err := syscall.BytePtrFromString(path)
    30  	if err != nil {
    31  		return err
    32  	}
    33  
    34  	_, _, errno := syscall6(uintptr(unsafe.Pointer(&procUnlinkat)), 3, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(flags), 0, 0, 0)
    35  	if errno != 0 {
    36  		return errno
    37  	}
    38  
    39  	return nil
    40  }
    41  
    42  func Openat(dirfd int, path string, flags int, perm uint32) (int, error) {
    43  	p, err := syscall.BytePtrFromString(path)
    44  	if err != nil {
    45  		return 0, err
    46  	}
    47  
    48  	fd, _, errno := syscall6(uintptr(unsafe.Pointer(&procOpenat)), 4, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(flags), uintptr(perm), 0, 0)
    49  	if errno != 0 {
    50  		return 0, errno
    51  	}
    52  
    53  	return int(fd), nil
    54  }
    55  
    56  func Fstatat(dirfd int, path string, stat *syscall.Stat_t, flags int) error {
    57  	p, err := syscall.BytePtrFromString(path)
    58  	if err != nil {
    59  		return err
    60  	}
    61  
    62  	_, _, errno := syscall6(uintptr(unsafe.Pointer(&procFstatat)), 4, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
    63  	if errno != 0 {
    64  		return errno
    65  	}
    66  
    67  	return nil
    68  }
    69  
    70  func Readlinkat(dirfd int, path string, buf []byte) (int, error) {
    71  	p0, err := syscall.BytePtrFromString(path)
    72  	if err != nil {
    73  		return 0, err
    74  	}
    75  	var p1 unsafe.Pointer
    76  	if len(buf) > 0 {
    77  		p1 = unsafe.Pointer(&buf[0])
    78  	} else {
    79  		p1 = unsafe.Pointer(&_zero)
    80  	}
    81  	n, _, errno := syscall6(uintptr(unsafe.Pointer(&procReadlinkat)), 4,
    82  		uintptr(dirfd),
    83  		uintptr(unsafe.Pointer(p0)),
    84  		uintptr(p1),
    85  		uintptr(len(buf)),
    86  		0, 0)
    87  	if errno != 0 {
    88  		return 0, errno
    89  	}
    90  
    91  	return int(n), nil
    92  }
    93  
    94  func Mkdirat(dirfd int, path string, mode uint32) error {
    95  	p, err := syscall.BytePtrFromString(path)
    96  	if err != nil {
    97  		return err
    98  	}
    99  
   100  	_, _, errno := syscall6(uintptr(unsafe.Pointer(&procMkdirat)), 3,
   101  		uintptr(dirfd),
   102  		uintptr(unsafe.Pointer(p)),
   103  		uintptr(mode),
   104  		0, 0, 0)
   105  	if errno != 0 {
   106  		return errno
   107  	}
   108  	return nil
   109  }
   110
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