scripts.go RawHistoryFolder

1// SPDX-License-Identifier: AGPL-3.0-or-later
2
3package githttp
4
5import (
6	"fmt"
7	"os"
8	"path/filepath"
9	"strings"
10)
11
12// WriteHookScripts writes the pre-receive and post-receive scripts into dir
13// (created if missing). Each is a /bin/sh script, mode 0755, that execs the
14// ermite binary at exe with `hook <name>`; exe is quoted for the shell. The
15// files are replaced atomically.
16func WriteHookScripts(dir, exe string) error {
17	if !filepath.IsAbs(exe) {
18		return fmt.Errorf("hook executable %q is not an absolute path", exe)
19	}
20	if strings.ContainsRune(exe, 0) || strings.ContainsAny(exe, "\n\r") {
21		return fmt.Errorf("hook executable path %q has control characters", exe)
22	}
23	if err := os.MkdirAll(dir, 0o700); err != nil {
24		return fmt.Errorf("create hooks directory: %w", err)
25	}
26	for _, hook := range []string{HookPreReceive, HookPostReceive} {
27		if err := writeExecutable(filepath.Join(dir, hook), hookScript(exe, hook)); err != nil {
28			return fmt.Errorf("write %s hook: %w", hook, err)
29		}
30	}
31	return nil
32}
33
34// hookScript returns the text of a hook script.
35func hookScript(exe, hook string) string {
36	return "#!/bin/sh\n# Written by ermite at start. Do not edit.\nexec " + shellQuote(exe) + " hook " + hook + "\n"
37}
38
39// shellQuote quotes s for /bin/sh with single quotes.
40func shellQuote(s string) string {
41	return "'" + strings.ReplaceAll(s, "'", `'\''`) + "'"
42}
43
44func writeExecutable(path, content string) error {
45	tmp, err := os.CreateTemp(filepath.Dir(path), ".hook-*")
46	if err != nil {
47		return err
48	}
49	defer func() { _ = os.Remove(tmp.Name()) }() // no-op after the rename
50	if _, err := tmp.WriteString(content); err != nil {
51		_ = tmp.Close()
52		return err
53	}
54	if err := tmp.Chmod(0o755); err != nil {
55		_ = tmp.Close()
56		return err
57	}
58	if err := tmp.Close(); err != nil {
59		return err
60	}
61	return os.Rename(tmp.Name(), path)
62}