mirror of git://gcc.gnu.org/git/gcc.git
109 lines
1.8 KiB
Go
109 lines
1.8 KiB
Go
// Copyright 2011 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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// Plan 9 environment variables.
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package syscall
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import (
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"errors"
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)
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var (
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errZeroLengthKey = errors.New("zero length key")
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errShortWrite = errors.New("i/o count too small")
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)
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func readenv(key string) (string, error) {
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fd, err := open("/env/"+key, 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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l, _ := Seek(fd, 0, 2)
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Seek(fd, 0, 0)
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buf := make([]byte, l)
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n, err := Read(fd, buf)
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if err != nil {
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return "", err
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}
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if n > 0 && buf[n-1] == 0 {
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buf = buf[:n-1]
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}
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return string(buf), nil
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}
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func writeenv(key, value string) error {
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fd, err := create("/env/"+key, O_RDWR, 0666)
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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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b := []byte(value)
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n, err := Write(fd, b)
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if err != nil {
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return err
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}
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if n != len(b) {
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return errShortWrite
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}
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return nil
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}
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func Getenv(key string) (value string, found bool) {
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if len(key) == 0 {
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return "", false
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}
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v, err := readenv(key)
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if err != nil {
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return "", false
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}
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return v, true
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}
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func Setenv(key, value string) error {
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if len(key) == 0 {
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return errZeroLengthKey
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}
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err := writeenv(key, value)
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if err != nil {
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return err
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}
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return nil
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}
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func Clearenv() {
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RawSyscall(SYS_RFORK, RFCENVG, 0, 0)
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}
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func Unsetenv(key string) error {
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if len(key) == 0 {
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return errZeroLengthKey
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}
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Remove("/env/" + key)
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return nil
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}
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func Environ() []string {
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fd, err := open("/env", O_RDONLY)
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if err != nil {
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return nil
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}
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defer Close(fd)
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files, err := readdirnames(fd)
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if err != nil {
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return nil
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}
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ret := make([]string, 0, len(files))
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for _, key := range files {
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v, err := readenv(key)
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if err != nil {
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continue
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}
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ret = append(ret, key+"="+v)
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}
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return ret
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}
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