README
¶
the-gpl
The Go Programming Language is a seminal programming language authored by Avengers: Alan A. A. Donovan and Brian W. Kernighan. This git repo is an attempt to share my learning from this book to showcase problems posed in the book and then some. The source-code by authors is on GitHub at gopl.io.
You can experience the deployed artifacts on the web as:
- GPC Cloud Run
the-gpl-bookservice.- Home, About
- Post data
- Lissajous Graph
- Mandel, Black & White
- Surfaces: Sinc, Eggs, Valley, Sq
- As docker container image.
- Curls eg:
curl https://the-gpl.com/who
Running from Web
You can start a webserver and see simple web-server examples. The command is:
$ the-gpl server -port=8080 # start a web server at port 8080.
Running from CLI
Assuming, the program is installed locally as the-gpl you can access several methods using a CLI.
To use autocompletion source the-gpl-autocomplete.sh.
Some examples are:
Google API examples
To use the Google Dialogflow Agent and Speech-to-text set up:
- GOOGLE_APPLICATION_CREDENTIALS shell variable
- Enable APIs
Here are commands to communicate with the Dialogflow Agent.
$ the-gpl # Prints the help of all modules
$ the-gpl bot -project=gcp-project-id # Will do a short conversation with an agent.
$ the-gpl bot -project=gcp-project-id -chat=true # Can send messages from stdin
$ the-gpl bot -chat=true -project=gcp-project-id -lang=en-US # Chat with an agent in en-US
To run live-caption speech to text first start a microphone stream on RTP port, and then use the-gpl to listen and apply STT.
$ ffmpeg -f avfoundation -i ":1" -acodec pcm_s16le -ar 48000 -f s16le udp://localhost:9999 # macOS Start microphone streaming
$ the-gpl stt -port=9999 # Will listen to RTP stream on port 9999 for 2 minutes and transcribe in real time
Simple Examples from book
Use these commands to run utilities:
- bits: That counts number of 1 bits in a Hex input
- Array examples using
masi.e., maps, arrays and string utilities. - Temperature conversions among
°F, °K and °C. - Measure disk usage in a directory using command
du - Saving Lissajous gif to a file.
$ the-gpl bits -n=0xBAD0FACE # will count 1 bits in n
$ the-gpl mas -fn=array # Tests array
$ the-gpl mas -fn=comp -n1=123 -n2=345 # Compare n1 and n2
# Temperature utilities
$ the-gpl temp -c=12 -f=12 -k=12 # Converts 12°C to °C/°F/°K
$ the-gpl degrees -c=12°F -f=12°K -k=12°C # Converts 12°C to °C/°F/°K
# du: Disk Usage calculates size of all files in a directory recursively, using go-routines
$ the-gpl du -dir=$HOME/gocode
# Output a Lissajous graph to -file of size 1024 pixels 20 frames and 10 cycles
$ the-gpl lissajous -file ~/Downloads/lis.gif -size=1024 -frames=20 -cycles=10
Crawling Examples
These commands fetch a website and does various operations on it.
# Parse various HTML content of sites URL
$ the-gpl parse -type=outline -site=https://www.airbnb.com # Creates a summary outline of a page
$ the-gpl parse -type=links -site=https://images.google.com # Prints all links on a webpage
$ the-gpl parse -type=images -site=https://www.yahoo.com # Fetches image URLs in a site
$ the-gpl parse -type=pretty -site=https://www.google.com
$ the-gpl parse -type=crawl -site=https://www.google.com -dir=/Users/guest/Downloads # Crawl pages to /Users/guest/Downloads/www.google.com
Simple Servers and Clients
# Server-client
$ the-gpl service -sp="clock:9999" # -sp servicePort start clock service on port 9999
$ the-gpl client -cp="clock:9999" # -cp clientPort start clock client on port 9999
$ nc localhost 9999 # use Mac netcat 'nc' client on port 9999
$ the-gpl service -sp="reverb:9998" # -sp servicePort start reverb service on port 9998
$ the-gpl client -cp="reverb:9998" # -cp clientPort start reverb client on port 9998
$ the-gpl service -sp="chat:9997" # starts a chat service. Join using:
$ nc localhost 9997 # Joins chat session as a client
Building from Local Machine
The GPL application can be built using:
- The plain old
go install - GCP Cloud run container.
- As a docker image on docker.com.
See The GPL Docker wiki for docker steps,
Mandelbrot
Here are some sample Mandelbrot fractals created.
Documentation
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
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Package chapter1, Tutorial, comprises miscellaneous examples.
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Package chapter1, Tutorial, comprises miscellaneous examples. |
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channels
Package channels provides basic examples of channels for functions that can be called as goroutine.
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Package channels provides basic examples of channels for functions that can be called as goroutine. |
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dup
Package dup is a placeholder for example that prints duplicate lines.
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Package dup is a placeholder for example that prints duplicate lines. |
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lissajous
Package lissajous outputs a .png image to a writer.
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Package lissajous outputs a .png image to a writer. |
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livecaption
Package livecaption implements Google speech-to-text API.
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Package livecaption implements Google speech-to-text API. |
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mas
Package mas is Example of Maps Arrays and Slices
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Package mas is Example of Maps Arrays and Slices |
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structs
Package structs provide example of a struct and its receiver or pointer receiver methods.
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Package structs provide example of a struct and its receiver or pointer receiver methods. |
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Package chapter2, Program Structure, features bit-counting and temperature conversion utilities.
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Package chapter2, Program Structure, features bit-counting and temperature conversion utilities. |
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bitsCount
Package bitsCount counts bits in a integer
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Package bitsCount counts bits in a integer |
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tempConv
Package tempConv provides conversion among Celsius, Kelvin and Fahrenheit using methods.
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Package tempConv provides conversion among Celsius, Kelvin and Fahrenheit using methods. |
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Package chapter3 provides utilities for mandelbrot and surface plots.
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Package chapter3 provides utilities for mandelbrot and surface plots. |
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Package chapter4 provides examples for http.Get, slices and composite literals.
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Package chapter4 provides examples for http.Get, slices and composite literals. |
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Package chapter5 is Functions, covers examples and exercises in the chapter.
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Package chapter5 is Functions, covers examples and exercises in the chapter. |
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Package chapter6, Methods, defines a IntSet utility.
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Package chapter6, Methods, defines a IntSet utility. |
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Package chapter7, Interfaces, defines bytes, words and line counter writer interfaces that can be used as part of fmt methods.
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Package chapter7, Interfaces, defines bytes, words and line counter writer interfaces that can be used as part of fmt methods. |
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Package chapter8, Goroutines and Channels, provides examples of sharing by communicating.
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Package chapter8, Goroutines and Channels, provides examples of sharing by communicating. |
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search
Package search composes a search request with user IP and user query.
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Package search composes a search request with user IP and user query. |
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search/google
Package google implements a Search using a deprecated API.
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Package google implements a Search using a deprecated API. |
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search/userip
Package userip is similar to golang.org/x/blog/content/context/userip
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Package userip is similar to golang.org/x/blog/content/context/userip |
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df
Package df Package bot establishes a client session with a Dialog Flow agent or bot associated with GCP project.
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Package df Package bot establishes a client session with a Dialog Flow agent or bot associated with GCP project. |
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Package logger defines a uniform logger for http handler functions.
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Package logger defines a uniform logger for http handler functions. |
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mocks
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df
Package mocks is a generated GoMock package.
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Package mocks is a generated GoMock package. |
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serve
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shell
Package shell provides interface for displaying help and executing
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Package shell provides interface for displaying help and executing |
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web
Package web serves a sample web server that hosts URLS to
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Package web serves a sample web server that hosts URLS to |
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