Existing interpreter handler

internal/cli/install.go

@@ -40,6 +40,7 @@ func newInstallCmd() *cobra.Command {
 				ZTS:        opts.ZTS,
 				AssumeYes:  globalOpts.Yes,
 				Out:        cmd.OutOrStdout(),
+				In:         cmd.InOrStdin(),
 			})
 		},
 	}

internal/ini/ini.go

@@ -33,6 +33,33 @@ func StripXdebugLoaders(content string) (string, []string) {
 	return strings.Join(kept, "\n"), removed
 }
 
+// CommentExtensionLoaders comments out every active extension= / zend_extension=
+// directive by prefixing it with "; ", returning the rewritten content and the
+// list of lines that were commented. Already-commented loaders and non-loader
+// lines are left unchanged.
+//
+// This is used when copying an existing php's config to a self-contained
+// debugger interpreter, which cannot load foreign .so files (they are built for
+// a specific PHP ABI). Commenting keeps them visible but inert. Note xdebug
+// loaders are removed entirely by StripXdebugLoaders and never reach here.
+func CommentExtensionLoaders(content string) (string, []string) {
+	lines := strings.Split(content, "\n")
+	var commented []string
+	for i, ln := range lines {
+		isComment, key, _, ok := parseDirective(ln)
+		if !ok || isComment || (key != "extension" && key != "zend_extension") {
+			continue
+		}
+		commented = append(commented, strings.TrimRight(ln, "\r"))
+		body, cr := ln, ""
+		if strings.HasSuffix(body, "\r") {
+			body, cr = body[:len(body)-1], "\r"
+		}
+		lines[i] = "; " + body + cr
+	}
+	return strings.Join(lines, "\n"), commented
+}
+
 // DisallowedModes returns the de-duplicated set of xdebug.mode tokens present in
 // xdebug.mode directives (active or commented out) that are not in AllowedModes,
 // preserving first-seen order. It is empty if xdebug.mode is absent or already

internal/ini/ini_test.go

@@ -80,6 +80,45 @@ func TestStripXdebugLoaders(t *testing.T) {
 	}
 }
 
+func TestCommentExtensionLoaders(t *testing.T) {
+	tests := []struct {
+		name          string
+		in            string
+		want          string
+		wantCommented []string
+	}{
+		{
+			name:          "comments active extension and zend_extension",
+			in:            "extension=mysqli.so\nzend_extension=/opt/opcache.so\nmemory_limit=256M\n",
+			want:          "; extension=mysqli.so\n; zend_extension=/opt/opcache.so\nmemory_limit=256M\n",
+			wantCommented: []string{"extension=mysqli.so", "zend_extension=/opt/opcache.so"},
+		},
+		{
+			name:          "leaves already-commented and non-loaders alone",
+			in:            ";extension=foo.so\ndisplay_errors=On\n",
+			want:          ";extension=foo.so\ndisplay_errors=On\n",
+			wantCommented: nil,
+		},
+		{
+			name:          "preserves CRLF",
+			in:            "extension=mysqli.so\r\nmemory_limit=256M\r\n",
+			want:          "; extension=mysqli.so\r\nmemory_limit=256M\r\n",
+			wantCommented: []string{"extension=mysqli.so"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, commented := CommentExtensionLoaders(tt.in)
+			if got != tt.want {
+				t.Errorf("content = %q, want %q", got, tt.want)
+			}
+			if !reflect.DeepEqual(commented, tt.wantCommented) {
+				t.Errorf("commented = %#v, want %#v", commented, tt.wantCommented)
+			}
+		})
+	}
+}
+
 func TestDisallowedModes(t *testing.T) {
 	tests := []struct {
 		name string

internal/installer/backup.go

@@ -0,0 +1,45 @@
+package installer
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// backupExisting moves the existing interpreter at srcPath into backupDir under a
+// unique name, preserving whatever it is (a real binary or a symlink). It falls
+// back to copy+remove if the move crosses filesystems. Returns the backup path.
+func backupExisting(srcPath, backupDir, key string, nowNanos int64) (string, error) {
+	if err := os.MkdirAll(backupDir, 0o755); err != nil {
+		return "", fmt.Errorf("creating backup dir: %w", err)
+	}
+	dst := filepath.Join(backupDir, fmt.Sprintf("php-%s-%d", key, nowNanos))
+
+	if err := os.Rename(srcPath, dst); err == nil {
+		return dst, nil
+	}
+	// Cross-device or other rename failure: copy the resolved binary, then remove
+	// the original.
+	if err := copyFile(srcPath, dst, 0o755); err != nil {
+		return "", fmt.Errorf("backing up %s: %w", srcPath, err)
+	}
+	if err := os.Remove(srcPath); err != nil {
+		os.Remove(dst)
+		return "", fmt.Errorf("removing original %s after backup: %w", srcPath, err)
+	}
+	return dst, nil
+}
+
+// restoreBackup moves a backup back to its original path.
+func restoreBackup(backupPath, originalPath string) error {
+	if err := os.MkdirAll(filepath.Dir(originalPath), 0o755); err != nil {
+		return err
+	}
+	if err := os.Rename(backupPath, originalPath); err == nil {
+		return nil
+	}
+	if err := copyFile(backupPath, originalPath, 0o755); err != nil {
+		return err
+	}
+	return os.Remove(backupPath)
+}

internal/installer/iniconfig.go

@@ -0,0 +1,147 @@
+package installer
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/php-debugger/installer/internal/ini"
+	"github.com/php-debugger/installer/internal/php"
+)
+
+// configPair is a source ini file and where its (sanitized) copy is written.
+type configPair struct{ src, dst string }
+
+// copyConfig copies the existing interpreter's ini files into the new
+// interpreter's compiled-in config path (so the new php loads the same
+// configuration), sanitizing each on the way: xdebug loader lines are stripped,
+// and disallowed xdebug.mode tokens are removed after confirmation.
+//
+// It registers undo steps on rb (restoring overwritten files / removing created
+// ones) and returns the list of destination files written.
+func copyConfig(existing, target *php.Info, rb *rollback, opts Options) ([]string, error) {
+	pairs := configPairs(existing, target)
+	if len(pairs) == 0 {
+		if target.Ini.ConfigPath == "" && target.Ini.ScanDir == "" {
+			opts.logf("Note: the interpreter reports no config path; skipping ini copy.")
+		}
+		return nil, nil
+	}
+
+	stripModes, err := decideStripModes(pairs, opts)
+	if err != nil {
+		return nil, err
+	}
+
+	var written []string
+	for _, pr := range pairs {
+		data, err := os.ReadFile(pr.src)
+		if err != nil {
+			return written, fmt.Errorf("reading ini %s: %w", pr.src, err)
+		}
+		content, removedLoaders := ini.StripXdebugLoaders(string(data))
+		content, commentedLoaders := ini.CommentExtensionLoaders(content)
+		if stripModes {
+			content, _, _ = ini.SanitizeXdebugMode(content)
+		}
+
+		if err := registerConfigUndo(pr.dst, rb); err != nil {
+			return written, err
+		}
+		if err := os.MkdirAll(filepath.Dir(pr.dst), 0o755); err != nil {
+			return written, fmt.Errorf("creating config dir: %w", err)
+		}
+		if err := os.WriteFile(pr.dst, []byte(content), 0o644); err != nil {
+			return written, fmt.Errorf("writing ini %s: %w", pr.dst, err)
+		}
+		written = append(written, pr.dst)
+		opts.logf("  wrote %s%s", pr.dst, loaderNote(len(removedLoaders), len(commentedLoaders)))
+	}
+	return written, nil
+}
+
+// configPairs builds the (source, destination) list: the existing main php.ini
+// goes to the new interpreter's ConfigPath, and each additional .ini goes to its
+// ScanDir (by base name).
+func configPairs(existing, target *php.Info) []configPair {
+	var pairs []configPair
+	if existing.Ini.LoadedFile != "" && target.Ini.ConfigPath != "" {
+		pairs = append(pairs, configPair{
+			src: existing.Ini.LoadedFile,
+			dst: filepath.Join(target.Ini.ConfigPath, "php.ini"),
+		})
+	}
+	if target.Ini.ScanDir != "" {
+		for _, f := range existing.Ini.AdditionalFiles {
+			pairs = append(pairs, configPair{
+				src: f,
+				dst: filepath.Join(target.Ini.ScanDir, filepath.Base(f)),
+			})
+		}
+	}
+	return pairs
+}
+
+// decideStripModes scans the source ini files for disallowed xdebug.mode tokens
+// and, if any are found, asks the user whether to remove them (auto-yes under
+// --yes). Returns true if the caller should sanitize xdebug.mode.
+func decideStripModes(pairs []configPair, opts Options) (bool, error) {
+	seen := map[string]bool{}
+	var disallowed []string
+	for _, pr := range pairs {
+		data, err := os.ReadFile(pr.src)
+		if err != nil {
+			return false, fmt.Errorf("reading ini %s: %w", pr.src, err)
+		}
+		for _, m := range ini.DisallowedModes(string(data)) {
+			if !seen[m] {
+				seen[m] = true
+				disallowed = append(disallowed, m)
+			}
+		}
+	}
+	if len(disallowed) == 0 {
+		return false, nil
+	}
+	sort.Strings(disallowed)
+	return opts.confirm(fmt.Sprintf(
+		"xdebug.mode lists disallowed mode(s): %s. Remove them (keeping only off/debug)?",
+		strings.Join(disallowed, ", "))), nil
+}
+
+// registerConfigUndo records how to undo writing dst: restore its prior contents
+// if it existed, otherwise remove it on rollback.
+func registerConfigUndo(dst string, rb *rollback) error {
+	if prev, err := os.ReadFile(dst); err == nil {
+		rb.add(func() error { return os.WriteFile(dst, prev, 0o644) })
+	} else if os.IsNotExist(err) {
+		rb.add(func() error { return removeIfExists(dst) })
+	} else {
+		return fmt.Errorf("inspecting %s: %w", dst, err)
+	}
+	return nil
+}
+
+func removeIfExists(path string) error {
+	if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return nil
+}
+
+// loaderNote summarizes what happened to extension loaders in a copied ini file.
+func loaderNote(removed, commented int) string {
+	var parts []string
+	if removed > 0 {
+		parts = append(parts, fmt.Sprintf("removed %d xdebug loader(s)", removed))
+	}
+	if commented > 0 {
+		parts = append(parts, fmt.Sprintf("commented %d extension loader(s)", commented))
+	}
+	if len(parts) == 0 {
+		return ""
+	}
+	return " (" + strings.Join(parts, ", ") + ")"
+}