107 lines
3.2 KiB
Markdown
107 lines
3.2 KiB
Markdown
# GO Playground
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This repo ist to learn and play with GO.
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All Code is written and tested on a Ubuntu 20.4 Linux.
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Learn more about [GO](https://go.dev/)
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## Install from Release
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```bash
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# Download release, change the number to latest release
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curl -OL https://golang.org/dl/go1.17.5.linux-amd64.tar.gz
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# verify integrity of download, compare with website's shown hash
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sha256sum go1.16.7.linux-amd64.tar.gz
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# extract tarball
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sudo tar -C /usr/local -xvf go1.17.5.linux-amd64.tar.gz
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# set up paths
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sudo nano ~/.profile
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> export PATH=$PATH:/usr/local/go/bin
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source ~/.profile
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# confirm installation
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which go
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go version
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```
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## Install from Source
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```bash
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# install requirements
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sudo apt install git gcc
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# get source repository
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git clone https://go.googlesource.com/go goroot
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cd goroot
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# <tag> is the version string of the release
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git checkout <tag>
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cd src
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# install
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./all.bash
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# test installation
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which go
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go version
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```
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The compilation environment can be customized by environment variables (but not required). Heres a short list
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- `$GOROOT`: root of the GO tree, often `$HOME/go1.X`
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- `$GOPATH`: directory where Go projects outside the Go distribution are typically checked out. Executables outside the Go distribution are installed in $GOPATH/bin (or $GOBIN, if set)
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- `$GOBIN`: directory where executables outside the Go distribution are installed using the go command
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To change any variable, edit your `~/.profile` file. Scroll all the way down to the end of the file and add the following with your specifications (sample here shows default values)
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```bash
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GOROOT=$HOME/go1.X
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GOPATH=$HOME/go
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GOBIN=$GOPATH/bin
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```
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Feel free to change it to your needs. Finally make the system aware of the new profile and run `source ~/.profile`
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### Update your GO Version
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GO releases can be fetched with the installed repository above. To never forget any release you can join the [golang-announce mailing list](https://groups.google.com/group/golang-announce).
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To update to the latest release, simply run
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```bash
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cd go/src
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git fetch
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# change <tag> to latest release tag e.g. go1.9
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git checkout <tag>
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./all.bash
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```
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## First programm
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```go
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package main
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import "fmt"
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func main() {
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fmt.Printf("hello, world\n")
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}
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```
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Build and run this program:
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```bash
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go run hello.go
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```
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## Code to binary
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The `go run` command is used as a shortcut for compiling and running a program that requires frequent changes.
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When you’ve finished your code and want to run it without compiling each time, use `go build` to turn your code into an executable binary. Building code into an executable binary consolidates the application into a single file with all the (support) code necessary to execute the binary.
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Once built, run `go install` to place the program on an executable file path to run it from anywhere on the system.
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To build and install executables you need an `go.mod` file with your executable definitions. Follow the [helloworld program](1-hello-world/hello.go) to see how.
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```bash
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# make sure to run from same directory as .go file
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go build
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# execute binary
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./hello
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# install to system
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go install
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# execute global binary
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hello
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```
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## Install additional tools
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Several Go tools are kept in the `golang.org/x/tools` repository. To install one of the tools, e.g. `gopls`:
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```bash
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go install golang.org/x/tools/gopls@latest
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``` |