go-a2cp is a small Go library for parsing and manipulating Apache2 .conf files.

• Parses directives (for example Listen 80)
• Parses nested block directives (for example <VirtualHost *:80> ... </VirtualHost>)
• Handles # comments (including inline comments)
• Preserves trailing comments on closing tags (for example </Directory> # end)
• Supports quoted arguments ("..." and '...')
• Supports line continuation using trailing \\
• Optional recursive include resolution for Include and IncludeOptional with unique line ranges per included file
• Supports AST manipulation (append/insert/remove/find/walk)
• Supports creating configs from scratch (builder-style API)
• Renders and writes modified config back to file

go get github.com/mxsgx/go-a2cp

• Go 1.26+
• OS: Linux, macOS, Windows

package main

import (
	"fmt"

	"github.com/mxsgx/go-a2cp"
)

func main() {
	src := `
<VirtualHost *:80>
    ServerName example.com
    DocumentRoot "/var/www/html"
</VirtualHost>
`

	doc, err := a2cp.ParseString(src)
	if err != nil {
		panic(err)
	}

	for _, stmt := range doc.Statements {
		switch s := stmt.(type) {
		case a2cp.Directive:
			fmt.Printf("directive: %s %v\n", s.Name, s.Args)
		case *a2cp.Block:
			fmt.Printf("block: <%s %v> children=%d\n", s.Name, s.Args, len(s.Children))
		}
	}
}

• ParseString(src string) (*Document, error)
• ParseReader(r io.Reader, opts ...ParseOption) (*Document, error)
• ParseFile(path string, opts ...ParseOption) (*Document, error)
• WithIncludeResolution(basePath string) ParseOption
• NewDocument() *Document
• NewDirective(name string, args ...string) Directive
• NewBlock(name string, args ...string) *Block
• WalkFunc func(stmt Statement, depth int) bool
• WithInlineComment() CommentOption
• WithRawCommentText() CommentOption
• (*Document).String() string
• (*Document).WriteTo(w io.Writer) (int64, error)
• (*Document).Save(path string) error
• (*Document).SaveWithMode(path string, mode os.FileMode) error
• (*Document).AddDirective(name string, args ...string) *Document
• (*Document).AddBlock(name string, args ...string) *Block
• (*Document).AddComment(text string, opts ...CommentOption) error
• (*Document).AddInlineComment(text string) error (compatibility alias)
• (*Document).Walk(fn WalkFunc)
• (*Document).FindDirectivesRecursive(name string) []Directive
• (*Document).FindBlocksRecursive(name string) []*Block
• (*Block).AddDirective(name string, args ...string) *Block
• (*Block).AddBlock(name string, args ...string) *Block
• (*Block).AddComment(text string, opts ...CommentOption) error
• (*Block).AddInlineComment(text string) error (compatibility alias)
• (*Block).Walk(fn WalkFunc)
• (*Block).FindDirectivesRecursive(name string) []Directive
• (*Block).FindBlocksRecursive(name string) []*Block

AddComment normalizes non-empty text by default so rendered comments use # prefix. Comment text is rendered safely: newline characters are escaped as \\n/\\r to avoid multi-line injection. Use WithRawCommentText() to preserve leading whitespace verbatim.

• AST nodes:
  • Comment
  • Directive
  • Block (includes EndComment for closing-tag trailing comments)
  • Document
  • Position

go test ./...

go test -v

Keep pull requests small and include tests for behavior changes.

Runnable examples are available in examples/:

• examples/parse-string: parse config from in-memory string
• examples/parse-file: parse a .conf file from disk
• examples/include-resolution: parse config with recursive Include expansion
• examples/include-optional-skip: parse config with missing IncludeOptional target (skipped)
• examples/comment-roundtrip: parse and render config while preserving comments
• examples/backslash-comments: parse continuation lines using trailing \ and preserve comments
• examples/walk: depth-first pre-order traversal of mixed AST statements
• examples/find-recursive: recursive directive/block lookup across all nesting levels
• examples/manipulate-save: modify AST and save generated config
• examples/from-scratch: build a full config from empty document and save it

Run each example from repository root:

go run ./examples/parse-string
go run ./examples/parse-file
go run ./examples/include-resolution
go run ./examples/include-optional-skip
go run ./examples/comment-roundtrip
go run ./examples/backslash-comments
go run ./examples/walk
go run ./examples/find-recursive
go run ./examples/manipulate-save
go run ./examples/from-scratch

package main

import a2cp "github.com/mxsgx/go-a2cp"

func main() {
	doc := a2cp.NewDocument()
	doc.AddDirective("Listen", "8080")

	vh := doc.AddBlock("VirtualHost", "*:8080")
	vh.AddDirective("ServerName", "scratch.local")
	vh.AddDirective("DocumentRoot", "/var/www/scratch")

	_ = doc.Save("apache2.from-scratch.conf")
}

package main

import (
	"log"

	"github.com/mxsgx/go-a2cp"
)

func main() {
	doc, err := a2cp.ParseFile("apache2.conf")
	if err != nil {
		log.Fatal(err)
	}

	// Add a top-level directive.
	doc.Append(a2cp.Directive{Name: "ServerTokens", Args: []string{"Prod"}})

	// Edit the first VirtualHost block if present.
	vhosts := doc.FindBlocks("VirtualHost")
	if len(vhosts) > 0 {
		vhosts[0].Append(a2cp.Directive{Name: "ServerAdmin", Args: []string{"admin@example.com"}})
	}

	if err := doc.Save("apache2.generated.conf"); err != nil {
		log.Fatal(err)
	}
}