go-tg-screenshot-bot

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// +build !darwin
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package dbus
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import (
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	"bytes"
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	"errors"
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	"fmt"
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	"io/ioutil"
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	"os"
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	"os/exec"
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	"os/user"
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	"path"
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	"strings"
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)
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var execCommand = exec.Command
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func getSessionBusPlatformAddress() (string, error) {
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	cmd := execCommand("dbus-launch")
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	b, err := cmd.CombinedOutput()
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	if err != nil {
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		return "", err
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	}
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	i := bytes.IndexByte(b, '=')
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	j := bytes.IndexByte(b, '\n')
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	if i == -1 || j == -1 || i > j {
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		return "", errors.New("dbus: couldn't determine address of session bus")
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	}
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	env, addr := string(b[0:i]), string(b[i+1:j])
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	os.Setenv(env, addr)
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	return addr, nil
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}
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// tryDiscoverDbusSessionBusAddress tries to discover an existing dbus session
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// and return the value of its DBUS_SESSION_BUS_ADDRESS.
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// It tries different techniques employed by different operating systems,
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// returning the first valid address it finds, or an empty string.
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//
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// * /run/user/<uid>/bus           if this exists, it *is* the bus socket. present on
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//                                 Ubuntu 18.04
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// * /run/user/<uid>/dbus-session: if this exists, it can be parsed for the bus
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//                                 address. present on Ubuntu 16.04
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//
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// See https://dbus.freedesktop.org/doc/dbus-launch.1.html
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func tryDiscoverDbusSessionBusAddress() string {
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	if runtimeDirectory, err := getRuntimeDirectory(); err == nil {
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		if runUserBusFile := path.Join(runtimeDirectory, "bus"); fileExists(runUserBusFile) {
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			// if /run/user/<uid>/bus exists, that file itself
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			// *is* the unix socket, so return its path
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			return fmt.Sprintf("unix:path=%s", EscapeBusAddressValue(runUserBusFile))
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		}
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		if runUserSessionDbusFile := path.Join(runtimeDirectory, "dbus-session"); fileExists(runUserSessionDbusFile) {
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			// if /run/user/<uid>/dbus-session exists, it's a
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			// text file // containing the address of the socket, e.g.:
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			// DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-E1c73yNqrG
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			if f, err := ioutil.ReadFile(runUserSessionDbusFile); err == nil {
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				fileContent := string(f)
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				prefix := "DBUS_SESSION_BUS_ADDRESS="
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				if strings.HasPrefix(fileContent, prefix) {
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					address := strings.TrimRight(strings.TrimPrefix(fileContent, prefix), "\n\r")
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					return address
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				}
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			}
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		}
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	}
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	return ""
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}
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func getRuntimeDirectory() (string, error) {
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	if currentUser, err := user.Current(); err != nil {
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		return "", err
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	} else {
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		return fmt.Sprintf("/run/user/%s", currentUser.Uid), nil
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	}
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}
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func fileExists(filename string) bool {
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	_, err := os.Stat(filename)
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	return !os.IsNotExist(err)
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}
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