mirror of https://go.googlesource.com/go
46 lines
1.3 KiB
Go
46 lines
1.3 KiB
Go
// Copyright 2023 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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//go:build unix
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package runtime
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func checkfds() {
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if islibrary || isarchive {
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// If the program is actually a library, presumably being consumed by
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// another program, we don't want to mess around with the file
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// descriptors.
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return
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}
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const (
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// F_GETFD, EBADF, O_RDWR are standard across all unixes we support, so
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// we define them here rather than in each of the OS specific files.
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F_GETFD = 0x01
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EBADF = 0x09
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O_RDWR = 0x02
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)
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devNull := []byte("/dev/null\x00")
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for i := 0; i < 3; i++ {
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ret, errno := fcntl(int32(i), F_GETFD, 0)
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if ret >= 0 {
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continue
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}
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if errno != EBADF {
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print("runtime: unexpected error while checking standard file descriptor ", i, ", errno=", errno, "\n")
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throw("cannot open standard fds")
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}
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if ret := open(&devNull[0], O_RDWR, 0); ret < 0 {
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print("runtime: standard file descriptor ", i, " closed, unable to open /dev/null, errno=", errno, "\n")
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throw("cannot open standard fds")
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} else if ret != int32(i) {
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print("runtime: opened unexpected file descriptor ", ret, " when attempting to open ", i, "\n")
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throw("cannot open standard fds")
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}
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}
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}
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