elvish/pkg/eval/builtin_fn_cmd_unix.go
Qi Xiao 6a1e7b3996 pkg/shell: Add more daemon-related tests.
Also:

- Remove duplicate code for closing daemon client.

- Avoid using (*testing.T).TempDir - it uses test name in the path, which can
  exceed the limit of the address when calling bind(2):
  https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_un.h.html#tag_13_6
7_04
2022-06-19 21:45:36 +01:00

119 lines
2.5 KiB
Go

//go:build !windows && !plan9
package eval
import (
"errors"
"os"
"os/exec"
"strconv"
"syscall"
"src.elv.sh/pkg/env"
"src.elv.sh/pkg/eval/errs"
"src.elv.sh/pkg/eval/vals"
"src.elv.sh/pkg/sys/eunix"
)
// 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? $args...
// ```
//
// Replace the Elvish process with an external `$command`, defaulting to
// `elvish`, passing the given arguments. This decrements `$E:SHLVL` before
// starting the new process.
//
// This command always raises an exception on Windows with the message "not
// supported on Windows".
// Reference to syscall.Exec. Can be overridden in tests.
var syscallExec = syscall.Exec
func execFn(fm *Frame, args ...any) 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
}
fm.Evaler.PreExit()
decSHLVL()
return syscallExec(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 errs.ArityMismatch{What: "arguments", ValidLow: 1, ValidHigh: -1, Actual: len(pids)}
}
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 := eunix.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)
}