exec、spawn、execFile、fork

child_process.exec(command[, options][, callback])

const{exec}=require("child_process")
/** 
  * 移动文件
*/
// exec("mv ./1.txt ./a ",{
//     cwd:__dirname
// },(error)=>{
//  console.log(error)
// })
/**
  * 删除文件
 */
// exec('rm ./a.txt')
/**
  * 复制文件目录
 */
// exec('cp -r ./1 ./b',{ 
//     cwd:__dirname
// },(error)=>{
//     console.log(error)
// })

exec 守护

const {exec}=require("child_process")
let serverList=['server1','server2']
serverList.forEach(serverName=>{
    server(`node ./${serverName}.js`)
})
function server(cmd){
   const worker=exec(cmd,(error,stdout,stderr)=>{
       if(error)return console.error(error)
   })
   worker.stdout.on('data',data=>{
       console.log(data)
   })
   worker.on("exit",(code)=>{
       if(code===1){
           setTimeout(()=>{
               server(cmd)
           },3000)
       }
   })
}

spawn

const{spawn}=require("child_process");
/**
  * 当前目录文件名
*/
// const showInfo=spawn('ls')
// showInfo.stdout.on("data",(data)=>{
//     console.log(data.toString())
// })
// showInfo.stderr.on("data",(data)=>{
//     console.log(`stderr:${data}`)
// })
// showInfo.on("close",(code)=>{
//     console.log(`子进程退出，退出码${code}`)
// })

spawn 守护

const {spawn}=require("child_process");
let serverList=['server1','server2']
serverList.forEach((serverName=>{
 server(`./${serverName}.js`)
}))
function server(cmd){
    const worker=spawn('node',[cmd])
    worker.stdout.on('data',data=>{
        console.log(data.toString())
    })
    worker.stderr.on("data",data=>{
        console.log(data.toString())
    })
    worker.on("exit",code=>{
        if(code===1){
            setTimeout(()=>{
                server(cmd)
            },3000)
        }
    })
}

child_process.execFile(file[, args][, options][, callback])

const {promisify}=require("util");
const {exec,execFile,spawn,fork}=require("child_process")
const _execFile=promisify(require("child_process").execFile)
// _execFile('node',['--vision']).then(res=>{
//     console.log(res.stdout)
// }).catch(err=>{
//     console.log(err)
// })

execFile 守护

const { execFile } = require("child_process")
let serverList = ['server1', 'server2']
serverList.forEach((serverName => {
    server(`./${serverName}.js`)
}))
function server(cmd) {
    const worker = execFile('node', [cmd],(error,stdout,stderr)=>{
        if(error)return console.log(error)
    })
    worker.stdout.on('data', data => {
        console.log(data)
    })
    worker.on("exit", (code) => {
        console.log(code)
        if (code === 1) {
            setTimeout(() => {
                server(cmd)
            }, 3000)
        }
    })
}

child_process.fork(modulePath[, args][, options])

const {work}=require("child_process") //从主进程中分离出的一个独立的子进程
function server(cmd){
    const worker=fork([cmd])
    worker.on("data",data=>{
        console.log(data。stdout.toString())
    })
}
let serverList=['server1','server2']
serverList.forEach(serverName=>{
    server(`./${serverName}.js`)
})

fork 守护

const {fork} =require("child_process")
let serverList=['server1','server2']
serverList.forEach(serverName=>{
   server(`./${serverName}.js`)
})
function server(cmd){
    const worker=fork([cmd])
    worker.on("data",(data)=>{
        console.log(data.stderr)
    })
    worker.on("exit",(code)=>{
        if(code===1){
            setTimeout(()=>{
                server(cmd)
            },3000)
        }
    })
}