Continue reading data after pausing for one second
php Editor Banana is here to share an interesting trick with you - "continue reading data after pausing for one second". In programming, sometimes we need to wait for a period of time before continuing to perform subsequent operations, and this technique can help us achieve this goal. Whether it is used for delayed operations of network requests, or to avoid certain time-consuming operations from affecting the execution efficiency of the program, this technique can play an important role. Below, we will introduce in detail how to implement this function in php.
Question content
I am using curl to get data from an endpoint and transfer it to the program. The main function of the program reads data like this
reader := bufio.NewReader(os.Stdin) var buf bytes.Buffer line, err := reader.ReadString(`\n`) for { if err != nil{ buf.WriteString(line) break } buf.WriteString(line) } var data Memstats err = json.Unmarshal(buf.Bytes(), &data)
Everything is normal until here. However, my end goal is to repeatedly curl the endpoint like this for a period of time so that the program reads N JSON blobs arriving at N time intervals.
for i in {1..10}; do curl localhost:6000/debug/vars | ./myprogram; sleep 1; done
Every time you curl to the endpoint, you will arrive at the same structured data. So I have to move the data reading code into function readStdIn
which I will call repeatedly until curl stops sending data and every time my program receives json data I will Unmarshal into a struct and add it to the slice. To call readStdIn repeatedly, I used a for loop, and to read the data in readStdIn, I also used a for loop. readStdIn
The function never completes. why not?
The main function
for{ reader := bufio.NewReader(os.Stdin) h.readStdIn(reader) time.Sleep(1 * time.Second) var err error //check to see if curl sent more data, if not I break out of main function and continue on with program and hopefully an array full of Memstats newbytes, err := reader.ReadByte() if err != nil{ break } }
readStdIn function
func (rt *Graph)readStdIn(reader *bufio.Reader){ var buf bytes.Buffer line, err := reader.ReadString('\n') for { if err != nil{ if err == io.EOF{ buf.WriteString(line) break }else{ fmt.Println(err.Error()) os.Exit(1) } } } buf.WriteString(line) } var data Memstats err = json.Marshal(buf.Bytes(), &data) rt.Memstats = append(rt.Memstats, &record) }
Solution
For parsing JSON
You can also use the scanner by customizing the function or changing the bash script. But I believe both are more complex than the code below.
<code>package main import ( "encoding/json" "errors" "fmt" "io" "os" ) func main() { fmt.Println("Start") decoder := json.NewDecoder(os.Stdin) for { var u User err := decoder.Decode(&u) if errors.Is(err, io.EOF) { fmt.Println("End") break } if err != nil { fmt.Println("Can not decode into json", err) continue } fmt.Println(u) } } type User struct { UserId int `json:"userId"` Id int `json:"id"` Title string `json:"title"` } </code>
<code>function repeatedCurl() { for i in $(seq 1 3); do # sleep 1 # optional you can emit curl -s "https://jsonplaceholder.typicode.com/posts/$i" done } repeatedCurl | ./foo </code>
For newline separated data
<code>package main import ( "bufio" "fmt" "os" ) func main() { fmt.Println("Start") scanner := bufio.NewScanner(bufio.NewReader(os.Stdin)) for scanner.Scan() { fmt.Println(scanner.Text()) } fmt.Println("End") } </code>
It works for both creating new program instances (like your example) and normal pipe usage.
Use the same pipe
<code>function repeatedDateEcho() { while sleep 1; do echo "$(date)" done } repeatedDateEcho | ./myprogram </code>
Output:
Start Thu Jan 18 22:59:31 +03 2024 Thu Jan 18 22:59:32 +03 2024 Thu Jan 18 22:59:33 +03 2024 Thu Jan 18 22:59:34 +03 2024
Use different pipes (new instance each time)
while sleep 1; do echo "$(date)" | ./my program; complete
Output:
Start Thu Jan 18 22:58:46 +03 2024 End Start Thu Jan 18 22:58:47 +03 2024 End
The above is the detailed content of Continue reading data after pausing for one second. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



OpenSSL, as an open source library widely used in secure communications, provides encryption algorithms, keys and certificate management functions. However, there are some known security vulnerabilities in its historical version, some of which are extremely harmful. This article will focus on common vulnerabilities and response measures for OpenSSL in Debian systems. DebianOpenSSL known vulnerabilities: OpenSSL has experienced several serious vulnerabilities, such as: Heart Bleeding Vulnerability (CVE-2014-0160): This vulnerability affects OpenSSL 1.0.1 to 1.0.1f and 1.0.2 to 1.0.2 beta versions. An attacker can use this vulnerability to unauthorized read sensitive information on the server, including encryption keys, etc.

The article explains how to use the pprof tool for analyzing Go performance, including enabling profiling, collecting data, and identifying common bottlenecks like CPU and memory issues.Character count: 159

The article discusses writing unit tests in Go, covering best practices, mocking techniques, and tools for efficient test management.

Queue threading problem in Go crawler Colly explores the problem of using the Colly crawler library in Go language, developers often encounter problems with threads and request queues. �...

The library used for floating-point number operation in Go language introduces how to ensure the accuracy is...

This article introduces a variety of methods and tools to monitor PostgreSQL databases under the Debian system, helping you to fully grasp database performance monitoring. 1. Use PostgreSQL to build-in monitoring view PostgreSQL itself provides multiple views for monitoring database activities: pg_stat_activity: displays database activities in real time, including connections, queries, transactions and other information. pg_stat_replication: Monitors replication status, especially suitable for stream replication clusters. pg_stat_database: Provides database statistics, such as database size, transaction commit/rollback times and other key indicators. 2. Use log analysis tool pgBadg

The article discusses the go fmt command in Go programming, which formats code to adhere to official style guidelines. It highlights the importance of go fmt for maintaining code consistency, readability, and reducing style debates. Best practices fo

Backend learning path: The exploration journey from front-end to back-end As a back-end beginner who transforms from front-end development, you already have the foundation of nodejs,...
