packer-cn/vendor/github.com/posener/complete/complete.go

105 lines
2.4 KiB
Go

package complete
import (
"flag"
"fmt"
"io"
"os"
"strconv"
"strings"
"github.com/posener/complete/cmd"
)
const (
envLine = "COMP_LINE"
envPoint = "COMP_POINT"
envDebug = "COMP_DEBUG"
)
// Complete structs define completion for a command with CLI options
type Complete struct {
Command Command
cmd.CLI
Out io.Writer
}
// New creates a new complete command.
// name is the name of command we want to auto complete.
// IMPORTANT: it must be the same name - if the auto complete
// completes the 'go' command, name must be equal to "go".
// command is the struct of the command completion.
func New(name string, command Command) *Complete {
return &Complete{
Command: command,
CLI: cmd.CLI{Name: name},
Out: os.Stdout,
}
}
// Run runs the completion and add installation flags beforehand.
// The flags are added to the main flag CommandLine variable.
func (c *Complete) Run() bool {
c.AddFlags(nil)
flag.Parse()
return c.Complete()
}
// Complete a command from completion line in environment variable,
// and print out the complete options.
// returns success if the completion ran or if the cli matched
// any of the given flags, false otherwise
// For installation: it assumes that flags were added and parsed before
// it was called.
func (c *Complete) Complete() bool {
line, point, ok := getEnv()
if !ok {
// make sure flags parsed,
// in case they were not added in the main program
return c.CLI.Run()
}
if point >= 0 && point < len(line) {
line = line[:point]
}
Log("Completing phrase: %s", line)
a := newArgs(line)
Log("Completing last field: %s", a.Last)
options := c.Command.Predict(a)
Log("Options: %s", options)
// filter only options that match the last argument
matches := []string{}
for _, option := range options {
if strings.HasPrefix(option, a.Last) {
matches = append(matches, option)
}
}
Log("Matches: %s", matches)
c.output(matches)
return true
}
func getEnv() (line string, point int, ok bool) {
line = os.Getenv(envLine)
if line == "" {
return
}
point, err := strconv.Atoi(os.Getenv(envPoint))
if err != nil {
// If failed parsing point for some reason, set it to point
// on the end of the line.
Log("Failed parsing point %s: %v", os.Getenv(envPoint), err)
point = len(line)
}
return line, point, true
}
func (c *Complete) output(options []string) {
// stdout of program defines the complete options
for _, option := range options {
fmt.Fprintln(c.Out, option)
}
}