go/packages/example_test.go

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package packages_test

import (
	"flag"
	"fmt"
	"os"

	"golang.org/x/tools/go/packages"
)

// Example demonstrates how to load the packages specified on the
// command line from source syntax.
func Example() {
	flag.Parse()

	// Many tools pass their command-line arguments (after any flags)
	// uninterpreted to packages.Load so that it can interpret them
	// according to the conventions of the underlying build system.
	cfg := &packages.Config{Mode: packages.NeedFiles | packages.NeedSyntax}
	pkgs, err := packages.Load(cfg, flag.Args()...)
	if err != nil {
		fmt.Fprintf(os.Stderr, "load: %v\n", err)
		os.Exit(1)
	}
	if packages.PrintErrors(pkgs) > 0 {
		os.Exit(1)
	}

	// Print the names of the source files
	// for each package listed on the command line.
	for _, pkg := range pkgs {
		fmt.Println(pkg.ID, pkg.GoFiles)
	}
}