Go Basics

Resources: http://golang.org/

Install and Setup

sudo apt-get install golang

http://golang.org/doc/code.html discusses setting up the GOLANG environment variable and your code repository

mkdir -p $HOME/projects/go/src
export GOPATH=$HOME/projects/go (add this to .profile too)

Hello World

// hello.go
package main

import (   
    "fmt"
    "os"
    "strings"
)

func main() {
    who := "World!"  
    if len(os.Args) > 1 { /* os.Args[0] is "hello" or "hello.exe" */  
        who = strings.Join(os.Args[1:], " ")  
    }
    fmt.Println("Hello", who)  
}

Commands

godoc -http=:8000                 # host docs at http://localhost:8000
go build                          # create binary file in local directory
go install                        # create binary file in $GOPATH/bin
go run                            # just run it, disposing of binary
go get github.com/nsf/gocode      # grab a remote package and install it to $GOPATH/bin
go get -u github.com/nsf/gocode   # update to latest version of remote package

Comments

// for end-of-line
/* for multiline */

Packages

• Every file should begin with a package statement.
• A package may be defined across several files.
• Code execution begins with a main() function inside package main

Variables

var i int        // declared, silently initialized to 0
var i int = 56   // declared and initialized
i := 56          // same thing, infers type from context; only allowed inside a function
i, j := 56, 67   // multiple assignment