in root dir
go build -o app
./app
The demo github has the test app icon on left side.
go env
Important variables are
- GOROOT defines where your Go SDK has been installed to, and
- GOPATH defines the root of your workspace, and will be the location where a lot of 3rd party source code, packages, and/or modules will be found
- GOENV is where your env is
go help environmentwill list info on each variable
Settings from go env output:
GOENV="/home/davis/.config/go/env"
GOROOT="/usr/lib/go-1.15"
GOPATH="/home/davis/go"
Display help on each variable
go help env
Brings up documentation for a package. Consider it the equvialent of a manpage.
go doc
go doc math
go doc math.Pow10
Build and run in one command
go run main.go
can build cross platform
go build
go build -o testy
GOOS=linux GOARCH=amd64 go build -o godemo-linux-amd64 .
GOOS=windows GOARCH=amd64 go build -o godemo-win-amd64 .
go tool dist list
go test .
# test two projects simultaneously
go test . util
go test -v -run=^TestGetX$ ./...
Get a module of a specific version
go get github.com/google/[email protected]
# get a specific commit
go get github.com/google/uuid@d460ce9
cat go.mod
see all of the dependencies that the current project is configured with. This will also now be reflected with a go.mod file:
go list -m all
List standard libraries
go list std
go mod init
rm go.mod go.sum
go mod init github.com/cloudacadmy/godemo
ls -la $(go env GOPATH)/pkg/mod/github.com/google
go mod verify
go get
cat go.mod
list out all dependent modules and whether an updated version exists and if so, what the latest semantic version number is.
go list -m all
go list -u -m all", used to
Prune out any required module declarations from the go.mod file if the module dependency is no longer used within the project source code anywhere.
go mod why -m github.com/google/uuid
# examine md5sum
go mod verify
go mod tidy
go list -u -m all
Used to reformat source code to what Go considers best practices. This
go fmt
This will reformat the code showing just the differences but not save the changes. The -s flag performs simplifications on the code. The -d flag performs a diff to highlight before and after. The absence of the -w flag allows you to examine the changes before applying them to the disk. Extending the same command with the -w flag will cause the changes to be saved.
# preview changes
gofmt -s -d main.go
# write the changes
gofmt -s -d -w main.go
# write the changes to all files recursively
gofmt -s -d -w .
# alternativewrite the changes to all files recursively
go fmt ./...
To perform this command recursively, use the following command: The go fmt ./... is a shortcut wrapper over the gofmt tool, and will perform the same reformatting recursively across the entire project, saving all updates to the disk in one hit.
gofmt -s -d -w .
go fmt ./..
The "go vet" command is used to perform a static analysis across your source code. It can be used to detect and report on code that although compiles may be considered problematic. For example, it can detect issues such as unreachable code. go vet can be called on single files, all files in the current directory, or across the entire project. As an example, if I were to add the following bad function implementation to the util calc.go file and then compiled it, it should compile even though it contains unreachable code, as it does. Let's now run go vet on it, and as you can see the static analysis has flagged the unreachable code.
go vet ./...
TODO