mirror of
https://github.com/autc04/Retro68.git
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94 lines
1.6 KiB
Go
94 lines
1.6 KiB
Go
// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// The working directory in Plan 9 is effectively per P, so different
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// goroutines and even the same goroutine as it's rescheduled on
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// different Ps can see different working directories.
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//
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// Instead, track a Go process-wide intent of the current working directory,
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// and switch to it at important points.
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package syscall
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import "sync"
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var (
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wdmu sync.Mutex // guards following
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wdSet bool
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wdStr string
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)
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func Fixwd() {
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wdmu.Lock()
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defer wdmu.Unlock()
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fixwdLocked()
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}
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func fixwdLocked() {
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if !wdSet {
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return
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}
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// always call chdir when getwd returns an error
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wd, _ := getwd()
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if wd == wdStr {
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return
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}
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if err := chdir(wdStr); err != nil {
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return
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}
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}
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func fixwd(paths ...string) {
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for _, path := range paths {
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if path != "" && path[0] != '/' && path[0] != '#' {
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Fixwd()
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return
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}
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}
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}
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// goroutine-specific getwd
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func getwd() (wd string, err error) {
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fd, err := open(".", O_RDONLY)
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if err != nil {
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return "", err
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}
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defer Close(fd)
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return Fd2path(fd)
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}
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func Getwd() (wd string, err error) {
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wdmu.Lock()
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defer wdmu.Unlock()
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if wdSet {
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return wdStr, nil
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}
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wd, err = getwd()
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if err != nil {
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return
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}
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wdSet = true
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wdStr = wd
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return wd, nil
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}
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func Chdir(path string) error {
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fixwd(path)
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wdmu.Lock()
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defer wdmu.Unlock()
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if err := chdir(path); err != nil {
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return err
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}
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wd, err := getwd()
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if err != nil {
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return err
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}
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wdSet = true
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wdStr = wd
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return nil
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}
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