1// Package shell provides cross-platform shell execution capabilities.
2//
3// WINDOWS COMPATIBILITY NOTE:
4// This implementation uses mvdan.cc/sh/v3 which provides POSIX shell emulation
5// on Windows. While this works for basic commands, it has limitations:
6// - Windows-specific commands (dir, type, copy) are not available
7// - PowerShell and cmd.exe specific features are not supported
8// - Some Windows path handling may be inconsistent
9//
10// For full Windows compatibility, consider adding native Windows shell support
11// using os/exec with cmd.exe or PowerShell for Windows-specific commands.
12package shell
13
14import (
15 "bytes"
16 "context"
17 "errors"
18 "fmt"
19 "os"
20 "strings"
21 "sync"
22
23 "github.com/charmbracelet/crush/internal/logging"
24 "mvdan.cc/sh/v3/expand"
25 "mvdan.cc/sh/v3/interp"
26 "mvdan.cc/sh/v3/syntax"
27)
28
29type PersistentShell struct {
30 env []string
31 cwd string
32 mu sync.Mutex
33}
34
35var (
36 once sync.Once
37 shellInstance *PersistentShell
38)
39
40func GetPersistentShell(cwd string) *PersistentShell {
41 once.Do(func() {
42 shellInstance = newPersistentShell(cwd)
43 })
44 return shellInstance
45}
46
47func newPersistentShell(cwd string) *PersistentShell {
48 return &PersistentShell{
49 cwd: cwd,
50 env: os.Environ(),
51 }
52}
53
54func (s *PersistentShell) Exec(ctx context.Context, command string) (string, string, error) {
55 s.mu.Lock()
56 defer s.mu.Unlock()
57
58 line, err := syntax.NewParser().Parse(strings.NewReader(command), "")
59 if err != nil {
60 return "", "", fmt.Errorf("could not parse command: %w", err)
61 }
62
63 var stdout, stderr bytes.Buffer
64 runner, err := interp.New(
65 interp.StdIO(nil, &stdout, &stderr),
66 interp.Interactive(false),
67 interp.Env(expand.ListEnviron(s.env...)),
68 interp.Dir(s.cwd),
69 )
70 if err != nil {
71 return "", "", fmt.Errorf("could not run command: %w", err)
72 }
73
74 err = runner.Run(ctx, line)
75 s.cwd = runner.Dir
76 s.env = []string{}
77 for name, vr := range runner.Vars {
78 s.env = append(s.env, fmt.Sprintf("%s=%s", name, vr.Str))
79 }
80 logging.InfoPersist("Command finished", "command", command, "err", err)
81 return stdout.String(), stderr.String(), err
82}
83
84func IsInterrupt(err error) bool {
85 return errors.Is(err, context.Canceled) ||
86 errors.Is(err, context.DeadlineExceeded)
87}
88
89func ExitCode(err error) int {
90 if err == nil {
91 return 0
92 }
93 status, ok := interp.IsExitStatus(err)
94 if ok {
95 return int(status)
96 }
97 return 1
98}