mirror of
https://github.com/go-sylixos/elvish.git
synced 2024-12-05 03:17:50 +08:00
114 lines
2.3 KiB
Go
114 lines
2.3 KiB
Go
// +build !windows,!plan9
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package eval
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import (
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"errors"
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"os"
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"os/exec"
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"strconv"
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"syscall"
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"github.com/elves/elvish/pkg/env"
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"github.com/elves/elvish/pkg/eval/vals"
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"github.com/elves/elvish/pkg/sys"
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)
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// ErrNotInSameProcessGroup is thrown when the process IDs passed to fg are not
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// in the same process group.
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var ErrNotInSameProcessGroup = errors.New("not in the same process group")
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//elvdoc:fn exec
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//
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// ```elvish
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// exec $command?
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// ```
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//
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// Replace the Elvish process with an external `$command`, defaulting to
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// `elvish`. This decrements `$E:SHLVL` before starting the new process.
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//
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// This command always raises an exception on Windows with the message "not
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// supported on Windows".
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func execFn(fm *Frame, args ...interface{}) error {
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var argstrings []string
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if len(args) == 0 {
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argstrings = []string{"elvish"}
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} else {
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argstrings = make([]string, len(args))
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for i, a := range args {
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argstrings[i] = vals.ToString(a)
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}
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}
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var err error
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argstrings[0], err = exec.LookPath(argstrings[0])
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if err != nil {
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return err
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}
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preExit(fm)
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decSHLVL()
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return syscall.Exec(argstrings[0], argstrings, os.Environ())
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}
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// Decrements $E:SHLVL. Called from execFn to ensure that $E:SHLVL remains the
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// same in the new command.
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func decSHLVL() {
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i, err := strconv.Atoi(os.Getenv(env.SHLVL))
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if err != nil {
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return
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}
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os.Setenv(env.SHLVL, strconv.Itoa(i-1))
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}
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func fg(pids ...int) error {
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if len(pids) == 0 {
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return ErrArgs
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}
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var thepgid int
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for i, pid := range pids {
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pgid, err := syscall.Getpgid(pid)
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if err != nil {
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return err
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}
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if i == 0 {
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thepgid = pgid
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} else if pgid != thepgid {
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return ErrNotInSameProcessGroup
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}
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}
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err := sys.Tcsetpgrp(0, thepgid)
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if err != nil {
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return err
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}
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errors := make([]*Exception, len(pids))
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for i, pid := range pids {
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err := syscall.Kill(pid, syscall.SIGCONT)
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if err != nil {
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errors[i] = &Exception{err, nil}
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}
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}
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for i, pid := range pids {
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if errors[i] != nil {
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continue
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}
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var ws syscall.WaitStatus
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_, err = syscall.Wait4(pid, &ws, syscall.WUNTRACED, nil)
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if err != nil {
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errors[i] = &Exception{err, nil}
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} else {
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// TODO find command name
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errors[i] = &Exception{NewExternalCmdExit(
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"[pid "+strconv.Itoa(pid)+"]", ws, pid), nil}
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}
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}
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return MakePipelineError(errors)
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}
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