oh-my-posh/environment_windows_win32.go

188 lines
4.9 KiB
Go

// +build windows
package main
import (
"fmt"
"regexp"
"strings"
"syscall"
"unsafe"
"golang.org/x/sys/windows"
)
// WindowsProcess is an implementation of Process for Windows.
type WindowsProcess struct {
pid int
ppid int
exe string
}
// getImagePid returns the
func getImagePid(imageName string) ([]int, error) {
processes, err := processes()
if err != nil {
return nil, err
}
var pids []int
for i := 0; i < len(processes); i++ {
if strings.ToLower(processes[i].exe) == imageName {
pids = append(pids, processes[i].pid)
}
}
return pids, nil
}
// getWindowTitle returns the title of a window linked to a process name
func getWindowTitle(imageName, windowTitleRegex string) (string, error) {
processPid, err := getImagePid(imageName)
if err != nil {
return "", nil
}
// is a spotify process running?
// no: returns an empty string
if len(processPid) == 0 {
return "", nil
}
// returns the first window of the first pid
_, windowTitle, err := GetWindowTitle(processPid[0], windowTitleRegex)
if err != nil {
return "", nil
}
return windowTitle, nil
}
func newWindowsProcess(e *windows.ProcessEntry32) *WindowsProcess {
// Find when the string ends for decoding
end := 0
for {
if e.ExeFile[end] == 0 {
break
}
end++
}
return &WindowsProcess{
pid: int(e.ProcessID),
ppid: int(e.ParentProcessID),
exe: syscall.UTF16ToString(e.ExeFile[:end]),
}
}
// Processes returns a snapshot of all the processes
// Taken and adapted from https://github.com/mitchellh/go-ps
func processes() ([]WindowsProcess, error) {
// get process table snapshot
handle, err := windows.CreateToolhelp32Snapshot(windows.TH32CS_SNAPPROCESS, 0)
if err != nil {
return nil, syscall.GetLastError()
}
defer func() {
_ = windows.CloseHandle(handle)
}()
// get process infor by looping through the snapshot
var entry windows.ProcessEntry32
entry.Size = uint32(unsafe.Sizeof(entry))
err = windows.Process32First(handle, &entry)
if err != nil {
return nil, fmt.Errorf("error retrieving process info")
}
results := make([]WindowsProcess, 0, 50)
for {
results = append(results, *newWindowsProcess(&entry))
err := windows.Process32Next(handle, &entry)
if err != nil {
if err == syscall.ERROR_NO_MORE_FILES {
break
}
return nil, fmt.Errorf("Fail to syscall Process32Next: %v", err)
}
}
return results, nil
}
// win32 specific code
// win32 dll load and function definitions
var (
user32 = syscall.NewLazyDLL("user32.dll")
procEnumWindows = user32.NewProc("EnumWindows")
procGetWindowTextW = user32.NewProc("GetWindowTextW")
procGetWindowThreadProcessID = user32.NewProc("GetWindowThreadProcessId")
)
// EnumWindows call EnumWindows from user32 and returns all active windows
// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumwindows
func EnumWindows(enumFunc, lparam uintptr) (err error) {
r1, _, e1 := syscall.Syscall(procEnumWindows.Addr(), 2, enumFunc, lparam, 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
// GetWindowText returns the title and text of a window from a window handle
// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getwindowtextw
func GetWindowText(hwnd syscall.Handle, str *uint16, maxCount int32) (length int32, err error) {
r0, _, e1 := syscall.Syscall(procGetWindowTextW.Addr(), 3, uintptr(hwnd), uintptr(unsafe.Pointer(str)), uintptr(maxCount))
length = int32(r0)
if length == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
// GetWindowTitle searches for a window attached to the pid
func GetWindowTitle(pid int, windowTitleRegex string) (syscall.Handle, string, error) {
var hwnd syscall.Handle
var title string
compiledRegex, err := regexp.Compile(windowTitleRegex)
if err != nil {
return 0, "", fmt.Errorf("Error while compiling the regex '%s'", windowTitleRegex)
}
// callback fro EnumWindows
cb := syscall.NewCallback(func(h syscall.Handle, p uintptr) uintptr {
var prcsID int = 0
// get pid
_, _, _ = procGetWindowThreadProcessID.Call(uintptr(h), uintptr(unsafe.Pointer(&prcsID)))
// check if pid matches spotify pid
if prcsID == pid {
b := make([]uint16, 200)
_, err := GetWindowText(h, &b[0], int32(len(b)))
if err != nil {
// ignore the error
return 1 // continue enumeration
}
title = syscall.UTF16ToString(b)
if compiledRegex.MatchString(title) {
// will cause EnumWindows to return 0 (error)
// but we don't want to enumerate all windows since we got what we want
hwnd = h
return 0
}
}
return 1 // continue enumeration
})
// Enumerates all top-level windows on the screen
// The error is not checked because if EnumWindows is stopped bofere enumerating all windows
// it returns 0(error occurred) instead of 1(success)
// In our case, title will equal "" or the title of the window anyway
_ = EnumWindows(cb, 0)
return hwnd, title, nil
}