Goでつまづいたところ

Go以前の話

El capitanでbrewを使う
sudo chown -R (whoami) /usr/local && brew prune && brew update

Macにインストール

古いgoは直接ディレクトリを消す。
sudo rm -r /usr/local/bin/go
古いpathを見ている場合は brew unlink　go する
brew install go

GOPATH

brew install goでMACにインストールした場合、GoPATHは次のように書いた

 export PATH=$PATH:$GOROOT/bin
 export GOROOT=/usr/local/Cellar/go/1.7.1/libexec
 export GOPATH=$HOME/_go <=好きなところ
　

httpサーバとstats確認

go-lang-api-stats-handerを使用

go get github.com/fukata/golang-stats-api-handler

sampleを以下変更

gostats.go

package main
import (
    "fmt"
    "net/http"
    "log"
    "github.com/fukata/golang-stats-api-handler"
)

func handler(w http.ResponseWriter, r *http.Request) {
  fmt.Fprintf(w, "Hello, World")
}

func main() {
    http.HandleFunc("/", stats_api.Handler)
    log.Fatal( http.ListenAndServe(":8080", nil) )
}

結果

$ curl -i http://localhost:8080
HTTP/1.1 200 OK
Content-Length: 513
Content-Type: application/json
Date: Thu, 15 Sep 2016 11:48:01 GMT

{"time":1473940081157567012,"go_version":"go1.7.1","go_os":"darwin","go_arch":"amd64","cpu_num":2,"goroutine_num":3,"gomaxprocs":2,"cgo_call_num":1,"memory_alloc":313712,"memory_total_alloc":313712,"memory_sys":3180792,"memory_lookups":7,"memory_mallocs":4896,"memory_frees":144,"memory_stack":294912,"heap_alloc":313712,"heap_sys":753664,"heap_idle":114688,"heap_inuse":638976,"heap_released":0,"heap_objects":4752,"gc_next":4194304,"gc_last":0,"gc_num":0,"gc_per_second":0,"gc_pause_per_second":0,"gc_pause":[]}

specの悪いPC

学んだこと

package mainは書かないとエラーとなり実行できない。
test.go:1:1: expected 'package', found 'import'