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// SPDX-License-Identifier: GPL-3.0-or-later
package config
import (
"bytes"
_ "embed"
"errors"
"fmt"
"io/fs"
"os"
"path/filepath"
"unicode"
"unicode/utf8"
"krino/internal/sexp"
"krino/internal/xdg"
)
//go:embed skel/krino.conf
var skelMain []byte
//go:embed skel/template.conf
var skelTemplate []byte
// Reserved are subcommand names; a directory with one of them could not be
// run by name.
var Reserved = map[string]bool{"init": true, "new": true, "check": true, "explain": true, "log": true, "undo": true}
// Init creates the directory holding mainFile with a commented krino.conf and
// template.conf, and a dirs/ directory. It never overwrites krino.conf, and
// keeps an existing template.conf. It returns the files it created.
func Init(mainFile string) ([]string, error) {
dir := filepath.Dir(mainFile)
if err := os.MkdirAll(dir, 0o755); err != nil {
return nil, err
}
if err := writeNew(mainFile, skelMain); errors.Is(err, fs.ErrExist) {
return nil, fmt.Errorf("%s already exists; krino init leaves it alone", mainFile)
} else if err != nil {
return nil, err
}
created := []string{mainFile}
if err := os.MkdirAll(filepath.Join(dir, "dirs"), 0o755); err != nil {
return created, err
}
tmpl := filepath.Join(dir, "template.conf")
switch err := writeNew(tmpl, skelTemplate); {
case err == nil:
created = append(created, tmpl)
case !errors.Is(err, fs.ErrExist):
return created, err
}
return created, nil
}
// NewDir creates dirs/<name>.conf from template.conf with the path filled
// in, and adds name to include in mainFile without changing anything else
// there. It returns the new file's path.
func NewDir(mainFile, name, path string) (string, error) {
if !nameRE.MatchString(name) {
return "", fmt.Errorf("bad directory name %q: use letters, digits, '.', '_' and '-'", name)
}
if Reserved[name] {
return "", fmt.Errorf("%q is a krino command; choose another name", name)
}
abs, err := filepath.Abs(xdg.Expand(path))
if err != nil {
return "", err
}
// The path is written into the new file, and config files are UTF-8
// text (the reader refuses anything else).
if !utf8.ValidString(abs) {
return "", fmt.Errorf("%q is not valid UTF-8; krino's config is UTF-8 text, so rename the directory first", abs)
}
// Nor control or bidirectional characters: a directory unpacked from a
// download could name itself with escape codes (re-review cli F1).
for _, r := range abs {
if unicode.IsControl(r) || unicode.Is(unicode.Bidi_Control, r) || unicode.In(r, unicode.Zl, unicode.Zp) {
return "", fmt.Errorf("%q holds control or bidirectional characters; rename the directory first", abs)
}
}
if fi, err := os.Stat(abs); err != nil || !fi.IsDir() {
return "", fmt.Errorf("%s is not a directory", abs)
}
src, err := os.ReadFile(mainFile)
if errors.Is(err, fs.ErrNotExist) {
return "", fmt.Errorf("%s not found; create it with: krino init", mainFile)
} else if err != nil {
return "", err
}
m, errs := ParseMain(mainFile, src)
if len(errs) > 0 {
return "", fmt.Errorf("fix %s first: %v", mainFile, errs[0])
}
if _, ok := m.IncludePos[name]; ok {
return "", fmt.Errorf("%q is already included", name)
}
tmplPath := filepath.Join(filepath.Dir(mainFile), "template.conf")
tmpl, err := os.ReadFile(tmplPath)
if errors.Is(err, fs.ErrNotExist) {
tmpl, err = skelTemplate, nil
}
if err != nil {
return "", err
}
file := DirFile(mainFile, name)
body := bytes.ReplaceAll(tmpl, []byte(`"@PATH@"`), []byte(sexp.Quote(xdg.Abbrev(abs))))
newDir, derrs := ParseDir(name, file, body)
if len(derrs) > 0 {
return "", fmt.Errorf("template.conf is broken: %v", derrs[0])
}
if newDir.Path != abs {
return "", fmt.Errorf("%s must contain (path \"@PATH@\")", tmplPath)
}
newMain := addInclude(src, m, name)
if _, errs := ParseMain(mainFile, newMain); len(errs) > 0 {
return "", fmt.Errorf("could not add %q to include: %v", name, errs[0])
}
if err := os.MkdirAll(filepath.Dir(file), 0o755); err != nil {
return "", err
}
if err := writeNew(file, body); errors.Is(err, fs.ErrExist) {
return "", fmt.Errorf("%s already exists", file)
} else if err != nil {
return "", err
}
if err := replaceFile(mainFile, newMain); err != nil {
os.Remove(file)
return "", err
}
return file, nil
}
// addInclude inserts name after the last element of the (include ...) form,
// or appends an include form when there is none.
func addInclude(src []byte, m *Main, name string) []byte {
ins := " " + sexp.Quote(name)
if m.IncludeNode == nil {
out := bytes.Clone(src)
if len(out) > 0 && out[len(out)-1] != '\n' {
out = append(out, '\n')
}
return append(out, "(include"+ins+")\n"...)
}
kids := m.IncludeNode.Children
at := kids[len(kids)-1].End.Offset
out := make([]byte, 0, len(src)+len(ins))
out = append(out, src[:at]...)
out = append(out, ins...)
return append(out, src[at:]...)
}
// writeNew creates path holding data, failing if it already exists.
func writeNew(path string, data []byte) error {
f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o644)
if err != nil {
return err
}
if _, err := f.Write(data); err != nil {
f.Close()
os.Remove(path)
return err
}
return f.Close()
}
// Replace atomically replaces the file at path with data, keeping its
// permissions and following a symlink to its target - what krino new does
// when it rewrites krino.conf. The GUI's rules editor saves through it, so
// there is one way krino writes a configuration file (GUI design §5.3).
func Replace(path string, data []byte) error { return replaceFile(path, data) }
// replaceFile atomically replaces the file at path, keeping its permissions.
// A symlink is followed and its target replaced, so dotfile links survive.
func replaceFile(path string, data []byte) error {
real, err := filepath.EvalSymlinks(path)
if err != nil {
return err
}
fi, err := os.Stat(real)
if err != nil {
return err
}
tmp, err := os.CreateTemp(filepath.Dir(real), ".krino-*")
if err != nil {
return err
}
defer os.Remove(tmp.Name())
if _, err := tmp.Write(data); err != nil {
tmp.Close()
return err
}
if err := tmp.Chmod(fi.Mode().Perm()); err != nil {
tmp.Close()
return err
}
if err := tmp.Sync(); err != nil {
tmp.Close()
return err
}
if err := tmp.Close(); err != nil {
return err
}
return os.Rename(tmp.Name(), real)
}
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