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package main
import (
"bufio"
"bytes"
"fmt"
"io"
"os"
"sort"
"strings"
"text/template"
"unicode"
"unicode/utf8"
"github.com/constabulary/gb/cmd"
)
func init() {
registerCommand(helpProject)
}
var helpProject = &cmd.Command{
Name: "project",
Short: "gb project layout",
Long: `A gb project is defined as any directory that contains a src/ subdirectory.
gb automatically detects the root of the project by looking at the current
working directory and walking backwards until it finds a directory that
contains a src/ subdirectory.
In the event you wish to override this auto detection mechanism, the -R flag
can be used to supply a project root.
See http://getgb.io/docs/project for details`,
}
var helpTemplate = `{{if .Runnable}}usage: gb {{.UsageLine}}
{{end}}{{.Long | trim}}
`
// help implements the 'help' command.
func help(args []string) {
if len(args) == 0 {
printUsage(os.Stdout)
// not exit 2: succeeded at 'gb help'.
return
}
if len(args) != 1 {
fmt.Fprintf(os.Stderr, "usage: gb help command\n\nToo many arguments given.\n")
exit(2) // failed at 'gb help'
}
arg := args[0]
// 'gb help documentation' generates alldocs.go.
if arg == "documentation" {
var buf bytes.Buffer
printUsage(&buf)
usage := &cmd.Command{Long: buf.String()}
f, _ := os.Create("alldocs.go")
tmpl(f, documentationTemplate, append([]*cmd.Command{usage}, sortedCommands()...))
f.Close()
return
}
for _, cmd := range commands {
if cmd.Name == arg {
tmpl(os.Stdout, helpTemplate, cmd)
// not exit 2: succeeded at 'gb help cmd'.
return
}
}
fmt.Fprintf(os.Stderr, "Unknown help topic %#q. Run 'gb help'.\n", arg)
exit(2) // failed at 'gb help cmd'
}
var usageTemplate = `gb, a project based build tool for the Go programming language.
Usage:
gb command [arguments]
The commands are:
{{range .}}{{if .Runnable}}
{{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}
Use "gb help [command]" for more information about a command.
Additional help topics:
{{range .}}{{if not .Runnable}}
{{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}
Use "gb help [topic]" for more information about that topic.
`
var documentationTemplate = `// DO NOT EDIT THIS FILE.
//go:generate gb help documentation
/*
{{range .}}{{if .Short}}{{.Short | capitalize}}
{{end}}{{if .Runnable}}Usage:
gb {{.UsageLine}}
{{end}}{{.Long | trim}}
{{end}}*/
package main
`
// tmpl executes the given template text on data, writing the result to w.
func tmpl(w io.Writer, text string, data interface{}) {
t := template.New("top")
t.Funcs(template.FuncMap{"trim": strings.TrimSpace, "capitalize": capitalize})
template.Must(t.Parse(text))
if err := t.Execute(w, data); err != nil {
panic(err)
}
}
func capitalize(s string) string {
if s == "" {
return s
}
r, n := utf8.DecodeRuneInString(s)
return string(unicode.ToTitle(r)) + s[n:]
}
func printUsage(w io.Writer) {
bw := bufio.NewWriter(w)
tmpl(bw, usageTemplate, sortedCommands())
bw.Flush()
}
func sortedCommands() []*cmd.Command {
// TODO(dfc) drop this and make main.commands a []*cmd.Command
var sortedKeys []string
for k := range commands {
sortedKeys = append(sortedKeys, k)
}
sort.Strings(sortedKeys)
var cmds []*cmd.Command
for _, c := range sortedKeys {
// skip hidden commands
if commands[c].Hidden() {
continue
}
cmds = append(cmds, commands[c])
}
return cmds
}
func usage() {
printUsage(os.Stderr)
exit(2)
}