go-ethereum/internal/build/util.go

139 lines
3.7 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package build
import (
"bytes"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"os"
"os/exec"
"path/filepath"
"strings"
"text/template"
)
var DryRunFlag = flag.Bool("n", false, "dry run, don't execute commands")
// MustRun executes the given command and exits the host process for
// any error.
func MustRun(cmd *exec.Cmd) {
fmt.Println(">>>", strings.Join(cmd.Args, " "))
if !*DryRunFlag {
cmd.Stderr = os.Stderr
cmd.Stdout = os.Stdout
if err := cmd.Run(); err != nil {
log.Fatal(err)
}
}
}
func MustRunCommand(cmd string, args ...string) {
MustRun(exec.Command(cmd, args...))
}
// GOPATH returns the value that the GOPATH environment
// variable should be set to.
func GOPATH() string {
if os.Getenv("GOPATH") == "" {
log.Fatal("GOPATH is not set")
}
return os.Getenv("GOPATH")
}
// VERSION returns the content of the VERSION file.
func VERSION() string {
version, err := ioutil.ReadFile("VERSION")
if err != nil {
log.Fatal(err)
}
return string(bytes.TrimSpace(version))
}
var warnedAboutGit bool
// RunGit runs a git subcommand and returns its output.
// The command must complete successfully.
func RunGit(args ...string) string {
cmd := exec.Command("git", args...)
var stdout, stderr bytes.Buffer
cmd.Stdout, cmd.Stderr = &stdout, &stderr
if err := cmd.Run(); err == exec.ErrNotFound {
if !warnedAboutGit {
log.Println("Warning: can't find 'git' in PATH")
warnedAboutGit = true
}
return ""
} else if err != nil {
log.Fatal(strings.Join(cmd.Args, " "), ": ", err, "\n", stderr.String())
}
return strings.TrimSpace(stdout.String())
}
// Render renders the given template file into outputFile.
func Render(templateFile, outputFile string, outputPerm os.FileMode, x interface{}) {
tpl := template.Must(template.ParseFiles(templateFile))
render(tpl, outputFile, outputPerm, x)
}
// RenderString renders the given template string into outputFile.
func RenderString(templateContent, outputFile string, outputPerm os.FileMode, x interface{}) {
tpl := template.Must(template.New("").Parse(templateContent))
render(tpl, outputFile, outputPerm, x)
}
func render(tpl *template.Template, outputFile string, outputPerm os.FileMode, x interface{}) {
if err := os.MkdirAll(filepath.Dir(outputFile), 0755); err != nil {
log.Fatal(err)
}
out, err := os.OpenFile(outputFile, os.O_CREATE|os.O_WRONLY|os.O_EXCL, outputPerm)
if err != nil {
log.Fatal(err)
}
if err := tpl.Execute(out, x); err != nil {
log.Fatal(err)
}
if err := out.Close(); err != nil {
log.Fatal(err)
}
}
// CopyFile copies a file.
func CopyFile(dst, src string, mode os.FileMode) {
if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
log.Fatal(err)
}
destFile, err := os.OpenFile(dst, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, mode)
if err != nil {
log.Fatal(err)
}
defer destFile.Close()
srcFile, err := os.Open(src)
if err != nil {
log.Fatal(err)
}
defer srcFile.Close()
if _, err := io.Copy(destFile, srcFile); err != nil {
log.Fatal(err)
}
}