/
helper.go
128 lines (111 loc) · 3.53 KB
/
helper.go
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package cli
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"github.com/spf13/cobra"
)
// WriteConfigVals writes a toml file with the given values.
// It returns an error if writing was impossible.
func WriteConfigVals(dir string, vals map[string]string) error {
data := ""
for k, v := range vals {
data += fmt.Sprintf("%s = \"%s\"\n", k, v)
}
cfile := filepath.Join(dir, "config.toml")
return ioutil.WriteFile(cfile, []byte(data), 0600)
}
// RunWithArgs executes the given command with the specified command line args
// and environmental variables set. It returns any error returned from cmd.Execute()
func RunWithArgs(cmd Executable, args []string, env map[string]string) error {
oargs := os.Args
oenv := map[string]string{}
// defer returns the environment back to normal
defer func() {
os.Args = oargs
for k, v := range oenv {
os.Setenv(k, v)
}
}()
// set the args and env how we want them
os.Args = args
for k, v := range env {
// backup old value if there, to restore at end
oenv[k] = os.Getenv(k)
err := os.Setenv(k, v)
if err != nil {
return err
}
}
// and finally run the command
return cmd.Execute()
}
// RunCaptureWithArgs executes the given command with the specified command
// line args and environmental variables set. It returns string fields
// representing output written to stdout and stderr, additionally any error
// from cmd.Execute() is also returned
func RunCaptureWithArgs(cmd Executable, args []string, env map[string]string) (stdout, stderr string, err error) {
oldout, olderr := os.Stdout, os.Stderr // keep backup of the real stdout
rOut, wOut, _ := os.Pipe()
rErr, wErr, _ := os.Pipe()
os.Stdout, os.Stderr = wOut, wErr
defer func() {
os.Stdout, os.Stderr = oldout, olderr // restoring the real stdout
}()
// copy the output in a separate goroutine so printing can't block indefinitely
copyStd := func(reader *os.File) *(chan string) {
stdC := make(chan string)
go func() {
var buf bytes.Buffer
// io.Copy will end when we call reader.Close() below
io.Copy(&buf, reader) //nolint:errcheck //ignore error
stdC <- buf.String()
}()
return &stdC
}
outC := copyStd(rOut)
errC := copyStd(rErr)
// now run the command
err = RunWithArgs(cmd, args, env)
// and grab the stdout to return
wOut.Close()
wErr.Close()
stdout = <-*outC
stderr = <-*errC
return stdout, stderr, err
}
// NewCompletionCmd returns a cobra.Command that generates bash and zsh
// completion scripts for the given root command. If hidden is true, the
// command will not show up in the root command's list of available commands.
func NewCompletionCmd(rootCmd *cobra.Command, hidden bool) *cobra.Command {
flagZsh := "zsh"
cmd := &cobra.Command{
Use: "completion",
Short: "Generate shell completion scripts",
Long: fmt.Sprintf(`Generate Bash and Zsh completion scripts and print them to STDOUT.
Once saved to file, a completion script can be loaded in the shell's
current session as shown:
$ . <(%s completion)
To configure your bash shell to load completions for each session add to
your $HOME/.bashrc or $HOME/.profile the following instruction:
. <(%s completion)
`, rootCmd.Use, rootCmd.Use),
RunE: func(cmd *cobra.Command, _ []string) error {
zsh, err := cmd.Flags().GetBool(flagZsh)
if err != nil {
return err
}
if zsh {
return rootCmd.GenZshCompletion(cmd.OutOrStdout())
}
return rootCmd.GenBashCompletion(cmd.OutOrStdout())
},
Hidden: hidden,
Args: cobra.NoArgs,
}
cmd.Flags().Bool(flagZsh, false, "Generate Zsh completion script")
return cmd
}