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429979a442
This patch adds the symlinkat(2) and readlinkat(2) system calls which are not exposed in golang 1.6. The implementation uses syscall.Syscall along with syscall.SYS_SYMLINKAT and SYS_READLINKAT which are, fortunately, available. Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
65 lines
1.8 KiB
Go
65 lines
1.8 KiB
Go
// -*- Mode: Go; indent-tabs-mode: t -*-
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/*
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* Copyright (C) 2018 Canonical Ltd
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 3 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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package osutil
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import (
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"syscall"
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"unsafe"
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)
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// Symlinkat is a direct pass-through to the symlinkat(2) system call.
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func Symlinkat(target string, dirfd int, linkpath string) error {
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targetPtr, err := syscall.BytePtrFromString(target)
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if err != nil {
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return err
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}
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linkpathPtr, err := syscall.BytePtrFromString(linkpath)
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if err != nil {
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return err
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}
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_, _, errno := syscall.Syscall(syscall.SYS_SYMLINKAT, uintptr(unsafe.Pointer(targetPtr)), uintptr(dirfd), uintptr(unsafe.Pointer(linkpathPtr)))
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if errno != 0 {
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return errno
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}
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return nil
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}
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// Readlinkat is a direct pass-through to the readlinkat(2) system call.
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func Readlinkat(dirfd int, path string, buf []byte) (n int, err error) {
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var zero uintptr
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pathPtr, err := syscall.BytePtrFromString(path)
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if err != nil {
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return 0, err
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}
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var bufPtr unsafe.Pointer
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if len(buf) > 0 {
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bufPtr = unsafe.Pointer(&buf[0])
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} else {
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bufPtr = unsafe.Pointer(&zero)
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}
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r0, _, errno := syscall.Syscall6(syscall.SYS_READLINKAT, uintptr(dirfd), uintptr(unsafe.Pointer(pathPtr)), uintptr(bufPtr), uintptr(len(buf)), 0, 0)
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n = int(r0)
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if errno != 0 {
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return 0, errno
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}
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return n, nil
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}
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