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46 snippets

Published:

Simple http server in Go

package main

import (
    "fmt"
    "net/http"
)

func hello(w http.ResponseWriter, req *http.Request) {
    fmt.Fprintf(w, "Hello, World!\n")
}

func headers(w http.ResponseWriter, req *http.Request) {
    for name, headers := range req.Header {
        for _, h := range headers {
            fmt.Fprintf(w, "%v: %v\n", name, h)
        }
    }
}

func main() {
    http.HandleFunc("/hello", hello)
    http.HandleFunc("/headers", headers)

    http.ListenAndServe(":8080", nil) // run http server on port 8080
}

Basic HTTP server using the net/http package. In the realm of net/http servers, a crucial concept involves handlers. These handlers implement http.Handler interface. A common method for creating a handler is to use http.HandlerFunc, applied to functions that have the required signature. Handlers receive a http.ResponseWriter and a http.Request as parameters. The response writer is employed to populate the HTTP response. Handlers can be registered on server routes by the http.HandleFunc function. This function configures the default router in the net/http package and accepts a function as its parameter. To start the http server, ListenAndServe is called with the specified port and handler. Passing nil as a second paramenter indicates using the default router we recently configured.

0 Burnfires

montana

Published:

Check if a file exists or not in Go

package main

import (
	"errors"
	"fmt"
	"os"
)

func main() {
	filePath := "file.txt"

	if _, err := os.Stat(filePath); errors.Is(err, os.ErrNotExist) {
		fmt.Println("file not exists")
	} else {
		fmt.Println("file exists")
	}
}

To check if a certain file exists inside a given directory in Golang, the Stat() and isNotExists() functions from the os package can be used. The Stat() function is used to return a file information structure that describes the file.

1 Burnfires

montana

Published:

Bash

How to detect OS in bash script?

#!/bin/bash

die()
{
    echo "ERROR: $*" >&2
    exit 1
}

detect_os ()
{
    OS="$(uname -s)"
    ARCH="$(uname -m)"

    case "$OS" in
        Linux)
            if [ -e /etc/lsb-release ]; then
                source /etc/lsb-release

                DIST_ID="${DISTRIB_ID}"
                OS_VERSION="${DISTRIB_RELEASE}"
                OS_CODENAME="${DISTRIB_CODENAME}"
            elif [ -e /etc/os-release]; then
                source /etc/os-release

                DIST_ID="${ID}"
                OS_VERSION="${VERSION_ID}"
                OS_CODENAME="${VERSION_CODENAME}"

            elif [ $(which lsb_release 2>/dev/null) ]; then
                DIST_ID="$(lsb_release -s -i)"
                OS_VERSION="$(lsb_release -s -r)"
                OS_CODENAME="$(lsb_release -s -c)"
            else
                die "Colud not get OS information"
            fi

            case "$DIST_ID" in
                RedHat*)
                    OS_NAME="RedHat" ;;
                debian)
                    OS_NAME="Debian" ;;
                *)
                    OS_NAME="${DIST_ID}" ;;
            esac
            ;;
        *)
            die "Unsupported OS family: $OS"
            ;;
    esac

    echo "${OS}"
    echo "${OS_NAME}"
    echo "${OS_VERSION}"
    echo "${OS_CODENAME}"
}

This script returns OS information such as type, name, codename and version. It supports the following Linux distributions: Ubuntu, Debian, CentOS, RedHat. If you want to add support for other distributions, write in the comments below.

0 Burnfires

alexsib

Published:

Python

Implementation of the Quick Sort algorithm in Python

def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    else:
        pivot = arr[0]
        left = [x for x in arr[1:] if x <= pivot]
        right = [x for x in arr[1:] if x > pivot]
        return quick_sort(left) + [pivot] + quick_sort(right)

# Example usage:
input_array = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]
sorted_array = quick_sort(input_array)

print("Original Array:", input_array)
print("Sorted Array:", sorted_array)

In this code, the quick_sort function is a recursive implementation of the Quick Sort algorithm. The pivot element is chosen as the first element of the array, and elements are partitioned into two sub-arrays (left and right) based on their relationship to the pivot. The function is then called recursively on the left and right sub-arrays until the entire array is sorted.

2 Burnfires

alexsib

Published:

PHP

Simple implementation of the Quick Sort algorithm in PHP

<?php

function quickSort(array $array): array
{
    $length = count($array);

    if ($length <= 1) {
        return $array;
    }

    $pivot = $array[0];
    $left = $right = [];

    for ($i = 1; $i < $length; $i++) {
        if ($array[$i] < $pivot) {
            $left[] = $array[$i];
        } else {
            $right[] = $array[$i];
        }
    }

    return array_merge(quickSort($left), [$pivot], quickSort($right));
}

// Example usage:
$array = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5];
$sortedArray = quickSort($array);

echo "Original Array: " . implode(", ", $array) . "\n";
echo "Sorted Array: " . implode(", ", $sortedArray) . "\n";

Here's a simple implementation of the Quick Sort algorithm in PHP

1 Burnfires

alexsib

Published:

Python

CSV file handling in Python

import csv

# Writing to a CSV file
with open('data.csv', 'w', newline='') as csvfile:
    fieldnames = ['name', 'age', 'city']
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)

    writer.writeheader()
    writer.writerow({'name': 'John', 'age': 30, 'city': 'New York'})
    writer.writerow({'name': 'Alice', 'age': 25, 'city': 'London'})

# Reading from a CSV file
with open('data.csv', newline='') as csvfile:
    reader = csv.DictReader(csvfile)
    for row in reader:
        print(row)

Examples of code for writing to a csv file and reading from a csv file.

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