lmcli/pkg/cli/util.go

package cli

import (
	"os"
	"os/exec"
	"strings"
)

// InputFromEditor retrieves user input by opening an editor (one specified by
// $EDITOR or 'vim' if $EDITOR is not set) on a temporary file. Once the editor
// closes, the contents of the file are read and the file is deleted. If the
// contents of the file exactly match the value of placeholder (no edits to the
// file were made), then an empty string is returned. Otherwise, the contents
// are returned. Example patten: message.*.md
func InputFromEditor(placeholder string, pattern string) (string, error) {
	msgFile, _ := os.CreateTemp("/tmp", pattern)
	defer os.Remove(msgFile.Name())

	os.WriteFile(msgFile.Name(), []byte(placeholder), os.ModeAppend)

	editor := os.Getenv("EDITOR")
	if editor == "" {
		editor = "vim" // default to vim if no EDITOR env variable
	}

	execCmd := exec.Command(editor, msgFile.Name())
	execCmd.Stdin = os.Stdin
	execCmd.Stdout = os.Stdout
	execCmd.Stderr = os.Stderr

	if err := execCmd.Run(); err != nil {
		return "", err
	}

	bytes, _ := os.ReadFile(msgFile.Name())
	content := string(bytes)

	if placeholder != "" {
		if content == placeholder {
			return "", nil
		}

		// strip placeholder if content begins with it
		if strings.HasPrefix(content, placeholder) {
			content = content[len(placeholder):]
		}
	}

	return content, nil
}