feat(app): add env var to specify PID file

Author: marjune163

README.md

@@ -14,7 +14,7 @@ Simple command line based HTTP file server to share local file system.
 
 ## Compile
 Minimal required Go version is 1.16.
-```bash
+```sh
 GO111MODULE=auto go build src/main.go
 ```
 Will generate executable file "main" in current directory.
@@ -287,6 +287,9 @@ ghfs [options]
 To prevent outputting additional information on console, like accessible URLs, etc,
 set value to "1".
 
+### GHFS_PID_FILE
+Specify PID file. PID will be written into the file on application startup.
+
 ## Shortcut key for default theme
 - `←`, `→`: move focus between path items
 - `Ctrl`/`Opt` + `←`: move focus to first path item

README.zh-CN.md

@@ -14,7 +14,7 @@
 
 ## 编译
 至少需要Go 1.16版本。
-```bash
+```sh
 GO111MODULE=auto go build src/main.go
 ```
 会在当前目录生成"main"可执行文件。
@@ -284,6 +284,9 @@ ghfs [选项]
 ### GHFS_QUIET
 为避免在控制台输出额外信息，例如可访问的URL等，可将值设为“1”。
 
+### GHFS_PID_FILE
+指定进程ID文件。进程ID会在应用启动时被写入文件。
+
 ## 默认主题的快捷键
 - `←`, `→`：使焦点在路径项之间移动
 - `Ctrl`/`Opt` + `←`：把焦点移动到第一个路径项

src/app/main.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strconv"
 )
 
 type App struct {
@@ -36,6 +37,8 @@ func (app *App) ReOpenLog() {
 }
 
 func NewApp(params []*param.Param) *App {
+	writePidFile()
+
 	verbose := !util.GetBoolEnv("GHFS_QUIET")
 
 	if serverHandler.TryEnableWSL1Fix() && verbose {
@@ -115,3 +118,18 @@ func NewApp(params []*param.Param) *App {
 		logFileMan:    logFileMan,
 	}
 }
+
+func writePidFile() {
+	pidFilename := os.Getenv("GHFS_PID_FILE")
+	if len(pidFilename) == 0 {
+		return
+	}
+
+	pidContent := strconv.Itoa(os.Getpid())
+	pidFile, err := os.OpenFile(pidFilename, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
+	if !serverErrHandler.CheckFatal(err) {
+		_, err := pidFile.WriteString(pidContent)
+		err2 := pidFile.Close()
+		serverErrHandler.CheckFatal(err, err2)
+	}
+}

test/case/037.pid.file.bash

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+cleanup() {
+	rm -f "$fs"/vhost1/pid.txt
+}
+
+source "$root"/lib.bash
+
+GHFS_PID_FILE="$fs"/vhost1/pid.txt "$ghfs" -l 3003 -r "$fs"/vhost1 &
+sleep 0.05 # wait server ready
+
+assert $(cat "$fs"/vhost1/pid.txt) $!
+
+cleanup
+jobs -p | xargs kill