39 lines
1 KiB
Go
39 lines
1 KiB
Go
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package system
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import (
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"io/ioutil"
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"strconv"
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"syscall"
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)
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// Works similarly to OpenBSD's "closefrom(2)":
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// The closefrom() call deletes all descriptors numbered fd and higher from
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// the per-process file descriptor table. It is effectively the same as
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// calling close(2) on each descriptor.
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// http://www.openbsd.org/cgi-bin/man.cgi?query=closefrom&sektion=2
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//
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// See also http://stackoverflow.com/a/918469/433558
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func CloseFdsFrom(minFd int) error {
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fdList, err := ioutil.ReadDir("/proc/self/fd")
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if err != nil {
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return err
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}
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for _, fi := range fdList {
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fd, err := strconv.Atoi(fi.Name())
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if err != nil {
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// ignore non-numeric file names
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continue
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}
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if fd < minFd {
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// ignore descriptors lower than our specified minimum
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continue
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}
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// intentionally ignore errors from syscall.Close
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syscall.Close(fd)
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// the cases where this might fail are basically file descriptors that have already been closed (including and especially the one that was created when ioutil.ReadDir did the "opendir" syscall)
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}
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return nil
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}
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