mirror of
https://github.com/go-sylixos/elvish.git
synced 2024-12-05 03:17:50 +08:00
b77a052e7e
This change is a preparation step for refining all *Op types to return Exception as the error. Keeping Exception as a struct type will make such a change error-prone, since a (*Exception)(nil) != error(nil), so if an *Op returns a nil *Exception, it is not nil if the return value is stored in an error-typed variable.
114 lines
2.3 KiB
Go
114 lines
2.3 KiB
Go
// +build !windows,!plan9
|
|
|
|
package eval
|
|
|
|
import (
|
|
"errors"
|
|
"os"
|
|
"os/exec"
|
|
"strconv"
|
|
"syscall"
|
|
|
|
"github.com/elves/elvish/pkg/env"
|
|
"github.com/elves/elvish/pkg/eval/vals"
|
|
"github.com/elves/elvish/pkg/sys"
|
|
)
|
|
|
|
// ErrNotInSameProcessGroup is thrown when the process IDs passed to fg are not
|
|
// in the same process group.
|
|
var ErrNotInSameProcessGroup = errors.New("not in the same process group")
|
|
|
|
//elvdoc:fn exec
|
|
//
|
|
// ```elvish
|
|
// exec $command?
|
|
// ```
|
|
//
|
|
// Replace the Elvish process with an external `$command`, defaulting to
|
|
// `elvish`. This decrements `$E:SHLVL` before starting the new process.
|
|
//
|
|
// This command always raises an exception on Windows with the message "not
|
|
// supported on Windows".
|
|
|
|
func execFn(fm *Frame, args ...interface{}) error {
|
|
var argstrings []string
|
|
if len(args) == 0 {
|
|
argstrings = []string{"elvish"}
|
|
} else {
|
|
argstrings = make([]string, len(args))
|
|
for i, a := range args {
|
|
argstrings[i] = vals.ToString(a)
|
|
}
|
|
}
|
|
|
|
var err error
|
|
argstrings[0], err = exec.LookPath(argstrings[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
preExit(fm)
|
|
decSHLVL()
|
|
|
|
return syscall.Exec(argstrings[0], argstrings, os.Environ())
|
|
}
|
|
|
|
// Decrements $E:SHLVL. Called from execFn to ensure that $E:SHLVL remains the
|
|
// same in the new command.
|
|
func decSHLVL() {
|
|
i, err := strconv.Atoi(os.Getenv(env.SHLVL))
|
|
if err != nil {
|
|
return
|
|
}
|
|
os.Setenv(env.SHLVL, strconv.Itoa(i-1))
|
|
}
|
|
|
|
func fg(pids ...int) error {
|
|
if len(pids) == 0 {
|
|
return ErrArgs
|
|
}
|
|
var thepgid int
|
|
for i, pid := range pids {
|
|
pgid, err := syscall.Getpgid(pid)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if i == 0 {
|
|
thepgid = pgid
|
|
} else if pgid != thepgid {
|
|
return ErrNotInSameProcessGroup
|
|
}
|
|
}
|
|
|
|
err := sys.Tcsetpgrp(0, thepgid)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
errors := make([]Exception, len(pids))
|
|
|
|
for i, pid := range pids {
|
|
err := syscall.Kill(pid, syscall.SIGCONT)
|
|
if err != nil {
|
|
errors[i] = &exception{err, nil}
|
|
}
|
|
}
|
|
|
|
for i, pid := range pids {
|
|
if errors[i] != nil {
|
|
continue
|
|
}
|
|
var ws syscall.WaitStatus
|
|
_, err = syscall.Wait4(pid, &ws, syscall.WUNTRACED, nil)
|
|
if err != nil {
|
|
errors[i] = &exception{err, nil}
|
|
} else {
|
|
// TODO find command name
|
|
errors[i] = &exception{NewExternalCmdExit(
|
|
"[pid "+strconv.Itoa(pid)+"]", ws, pid), nil}
|
|
}
|
|
}
|
|
|
|
return MakePipelineError(errors)
|
|
}
|