gpl

The Go Programming Language book

I have worked briefly with Go in the past, but never followed through since I mainly work with PHP & Javascript. This is where I pick it up again with the book "The Go Programming Language" taking it easy and going through the examples and exercises in the book.

I've set this up to use Cobra CLI framework and attempt to solve the exercises in the book in single file command/sub-commands as I go.

Command dedup

Simple command to count the number of occurrences of text line from input. Input can be os.Stdin or file(s)

# From os.Stdout
cat cmd/text.txt | ./gpl dedup
50      Some text
50      Followed by different text
50      Then more
50      And some more

./gpl dedup < data/dedup/text.txt
50      And some more
50      Some text
50      Followed by different text
50      Then more

# From file
./gpl dedup file data/dedup/text.txt
File:   data/dedup/text.txt
50      Some text
50      Followed by different text
50      Then more
50      And some more

Command lissajous

Simple command to create GIF images with Lissajous curve graphs. sci-fi effect from the 1960s

cat ./gpl lissajous

This outputs a file lissajous.gif in current directory.

Command fetch

Simple command to fetch given urls concurrently, reports status code and content length. Follows redirects keeping cookies

# Using wait group to manage go routines
./gpl fetch --url https://google.com --url https://github.com --url https://slack.com
URLs to fetch: [https://google.com https://github.com https://slack.com]
---------------
Url:    https://github.com
StatusCode:     200
Length: 300.2kB
Fetch time:     0.246s
---------------
Url:    https://slack.com
StatusCode:     200
Length: 96.65kB
Fetch time:     0.313s
---------------
Url:    https://google.com
StatusCode:     200
Length: 13.45kB
Fetch time:     0.371s
---------------
Command time: 0.371s

# Using channels to manage go routines
./gpl fetch --use-channels --url https://google.com --url https://github.com --url https://slack.com
URLs to fetch: [https://google.com https://github.com https://slack.com]
---------------
Url:    https://github.com
StatusCode:     200
Length: 300.2kB
Fetch timei:    0.237s
---------------
Url:    https://google.com
StatusCode:     200
Length: 13.45kB
Fetch timei:    0.335s
---------------
Url:    https://slack.com
StatusCode:     200
Length: 96.92kB
Fetch timei:    0.336s
---------------
Command time: 0.336s