truthhun / go-1

:speech_balloon: I incorporate these code snippets into my larger programming modules.

Exploring Golang features

You can incorporate these code snippets into your larger programming modules. This repository is viewable on sourcegraph.com.

Contents

Name	Description
00_persisting_go	Installing Go, persisting on systemd, Upstart
01_data_type	type, error, recursion, reference, slice, switch, pointer
02_mongodb_aggregate_cli	aggregate data from mongodb displayed in CLI
03_mongodb_find_sort_cli	MongoDB Find All, Sort commands, results in CLI
04_get_url_variable	Get "FormValue" variable from URL
05_mongodb_crud_cli	Insert, Update, Drop, Find, Index commands, results in CLI
06_ajax_send_receive	Two Ajax examples: read and write
07_one_page_template	GO code and HTML template in one file
08_gowiki	Simple wiki example
09_todo_list_html	Todo list with struct and HTML template.
10_mongodb	Mongodb query results on HTML page in one go file.
11_socket_send_receive	Send/receive text between client/server via socket.
12_mgo_pipeline	Mongodb pipeline query saved in one go file
13_qr_barcode	QR code generator displays PNG image in browser.
14_read_txt_file	compare ways to process TXT file
15_png_or_svg_barchart	generate bar chart, PNG or SVG
16_drop_down_menu_form	Form /w drop down menu, template with sub-templates
17_mysql_user_login	MySQL for user registration, login, and user list.
18_cookie_authentication	Authentication with cookies.
19_os_global_variables	Displaying all global system variables.
20_mongodb_crud	Mongodb CRUD with REST using httprouter & HTML templates
21_httprouter_template	html template with httprouter and ServeFiles
22_mongodb_crud_rest_html	Mongodb CRUD with REST using httprouter & HTML templates
23_file_uploader	Upload file and save on server
24_calculate_time	Find out how much time it takes for function to start and finish
25_https_static_files	Serve HTTP and HTTPS w/ NotFound for static files
26_url_not_found_handler	Custom Not Found handler.
27_mongodb_bulk_upsert	Mongodb bulk insert from TXT file
28_markdown	Generate Markdown using blackfriday
29_go_crud_json_api	REST API using JSON with httprouter. JavaScript is used to view, create, edit, and delete records.
30_mongodb_crud_json_api	REST API using JSON, httprouter, and toml, i/o to MongoDB
31_send_email	Send email with attachment
32_colorful_cli	Create colorful CLI
33_testing	testing package example
34_html_template_function	Pass function to HTML template
35_mongodb_pipeline_page	One page MGO aggregation with pipeline
36_concurrency_channel	channel, waiting, concurrency, sleep, close, count, queue
37_html_template	Simple html template with Go
38_url_request_JSON	Convert data to/from JSON, get and parse file from URL
39_read_directory_content	List files adn sub folders in a given folder
40_cron_scheduler	Schedule processes
41_cli_arguments	Run cli utility with options using os.Args
42_upload_many_files	Upload multiple files from browser form to folder on a server.
43_resize_jpg_png_image	Resize images
44_csv_file	Read and write to CSV file. Parse CSV file to slice of objects.
45_image_exif_data	Get image attributes for each image in a folder.
46_video_capture	Capture video from web camera and display live.
47_download_slice_as_csv	Download link generates CSV or Tab Delimited file that can be saved localy on your computer.
48_keyboard_driver	Testing IOT devices
49_constructor	Example creating new package with allocation/constructor that accepts multiple types using interface. Experimenting with Readers and Writers.
50_golf_framework	A fast, simple and lightweight micro-web framework for Go
51_blur_image	Blur, Rotate, and Generate Thumbnails.
52_jpg_image_watermark	Add watermark to image
53_regular_expression	Validation, Find and replace, security
54_rotate_image	Image rotation in degrees from 1 to 360.
55_html_template_std_lib	HTML template using standard library packages
56_HTML_formatter	Work in similar fashion as go fmt, but on HTML files.

The proper way to copy a slice

package main

import "fmt"

func main() {
	a := []string{"a", "b", "c", "d"}
	e := make([]string, len(a))
	copy(e, a)
	fmt.Println(e)
}

How to find out the data type?

// Figure out what type it is: maps, slices, or arrays!

package main

import (
	"fmt"
	"reflect"
)

func main() {

	// Declaring local variables
	map1 := map[string]string{"name": "John", "desc": "Golang"}
	map2 := map[string]int{"apple": 23, "tomato": 13}
	slice1 := []int{1, 2, 3}
	array1 := [3]int{1, 2, 3}
	// var m map[string]int
	// m = make(map[string]int)
	// More info Here: https://blog.golang.org/go-maps-in-action

	// Type, such as map[string]string, []int, [3]int
	fmt.Println("map1:", reflect.TypeOf(map1))
	fmt.Println("map2:", reflect.TypeOf(map2))
	fmt.Println("slice1:", reflect.TypeOf(slice1))
	fmt.Println("array1:", reflect.TypeOf(array1))

	// Value, such as map, slice, array.
	fmt.Println("map1:", reflect.ValueOf(map1).Kind())
	fmt.Println("map2:", reflect.ValueOf(map2).Kind())
	fmt.Println("slice1:", reflect.ValueOf(slice1).Kind())
	fmt.Println("array1:", reflect.ValueOf(array1).Kind())

	// True/False statement inside Printf
	fmt.Printf("%v is a map? %v\n", map1, reflect.ValueOf(map1).Kind() == reflect.Map)
	fmt.Printf("%v is a map? %v\n", map2, reflect.ValueOf(map2).Kind() == reflect.Map)
	fmt.Printf("%v is a map? %v\n", slice1, reflect.ValueOf(slice1).Kind() == reflect.Map)

	/*  More about reflect package: https://golang.org/pkg/reflect/
		 	Invalid Kind = iota
	        Bool
	        Int
	        Int8
	        Int16
	        Int32
	        Int64
	        Uint
	        Uint8
	        Uint16
	        Uint32
	        Uint64
	        Uintptr
	        Float32
	        Float64
	        Complex64
	        Complex128
	        Array
	        Chan
	        Func
	        Interface
	        Map
	        Ptr
	        Slice
	        String
	        Struct
	        UnsafePointer
	*/
}

In Go, the code does exactly what it says on the page.

It’s the simplicity that makes Go awesome.

Go strives to keep things small and beautiful.