================
CODE SNIPPETS
================
TITLE: List Go Examples using 'go test -list'
DESCRIPTION: This snippet illustrates how to list all functions starting with 'Example' in a Go project. The command 'go test -list=Example' is executed, and expected output includes 'Example_simple' and 'Example_withEmptyOutput'.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/list_test_simple.txt#_snippet_2

LANGUAGE: bash
CODE:
```
go test -list=Example
stdout Example_simple
stdout Example_withEmptyOutput
```

--------------------------------

TITLE: Install Go Module Executable
DESCRIPTION: Compiles and installs the specified module as an executable. The binary is placed in the Go bin directory.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/version_replace.txt#_snippet_2

LANGUAGE: go
CODE:
```
go install example.com/printversion
```

--------------------------------

TITLE: Go Get: Remove Dependencies with '@none'
DESCRIPTION: This example shows how to remove all modules matching a wildcard pattern using '@none' with 'go get'. It fetches all packages under 'example.net' with '@none' and verifies that no dependencies matching the prefix remain in the module list.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_split.txt#_snippet_6

LANGUAGE: bash
CODE:
```
go get example.net/...

go get example.net/...
go list -m all
! stdout '^example.net'
```

--------------------------------

TITLE: Configuring Go Project Structure and Dependencies
DESCRIPTION: Sets up Go package directories, copies source files and pre-compiled archives, and installs a package using 'go install -x'. This tests how the Go toolchain resolves dependencies based on GOPATH.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_gopath_order.txt#_snippet_1

LANGUAGE: bash
CODE:
```
mkdir $WORK/p1/src/foo $WORK/p2/src/baz
mkdir $WORK/p2/pkg/${GOOS}_${GOARCH} $WORK/p1/src/bar
cp foo.go $WORK/p1/src/foo/foo.go
cp baz.go $WORK/p2/src/baz/baz.go
cp foo.a $WORK/p2/pkg/${GOOS}_${GOARCH}/foo.a
cp bar.go $WORK/p1/src/bar/bar.go

go install -x bar
```

--------------------------------

TITLE: Installing and Testing Test2JSON Tool
DESCRIPTION: This code snippet focuses on installing the 'test2json' tool into the Go environment and verifying its successful installation and execution. It checks for the tool's existence in the correct directory and confirms its output when run. It also verifies that the 'go tool -n test2json' command points to the newly installed tool.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/tool_build_as_needed.txt#_snippet_2

LANGUAGE: bash
CODE:
```
# GOROOT with test2json uses the test2json in the GOROOT
go install cmd/test2json
exists $TOOLDIR/test2json$GOEXE
go tool test2json
stdout '{"Action":"start"}'
go tool -n test2json
stdout $NEWTOOLDIR${/}test2json$GOEXE
```

--------------------------------

TITLE: Install Go Module with Specific Version
DESCRIPTION: Uses the 'go get' command to download and install a specific version of a Go module. This is a common way to manage dependencies in Go projects.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/badgo.txt#_snippet_0

LANGUAGE: bash
CODE:
```
go get example.net/badgo@v1.0.0
go get example.net/badgo@v1.1.0
go get example.net/badgo@v1.2.0
go get example.net/badgo@v1.3.0
go get example.net/badgo@v1.4.0
go get example.net/badgo@v1.5.0
go get example.net/badgo@v1.6.0
```

--------------------------------

TITLE: Install echo command for Windows
DESCRIPTION: Installs the 'echo' command for Windows environments where it's not natively available. It sets the GOBIN environment variable and then uses 'go install' to install 'echo.go'. Finally, it updates the PATH to include the new GOBIN directory.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/generate.txt#_snippet_0

LANGUAGE: bash
CODE:
```
env GOBIN=$WORK/tmp/bin
go install echo.go
env PATH=$GOBIN:${:}$PATH
```

--------------------------------

TITLE: Go Work File Example
DESCRIPTION: This is an example content of a go.work file, specifying the Go version and the local workspace.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_get_toolchain.txt#_snippet_2

LANGUAGE: go.work
CODE:
```
go 1.18
use .

```

--------------------------------

TITLE: Go Module Workspace Setup and Retraction Demonstration
DESCRIPTION: This snippet demonstrates setting up a Go workspace and retrieving a module with a retracted version. It involves copying a go.mod file, unsetting the GOWORK environment variable, fetching a specific module version, and observing 'retracted' messages in the standard error.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_12

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
env GOWORK=
go get example.com/retract@v1.0.0-good
stderr 'retracted'
```

--------------------------------

TITLE: Go Get: Wildcard Fetch with Version Mismatch
DESCRIPTION: This example demonstrates the behavior of 'go get' when a wildcard pattern matches packages in a module but not at the requested version. It shows how the command fails and provides an error message indicating the version mismatch for the module.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_split.txt#_snippet_2

LANGUAGE: bash
CODE:
```
! go get example.net/split/nested/...
stderr '^go: example.net/split/nested/\.\.\.@v0.1.0 matches packages in example.net/split@v0.2.0 but not example.net/split@v0.1.0: specify a different version for module example.net/split$'

cmp go.mod go.mod.orig
```

--------------------------------

TITLE: Go Source Code (Example A)
DESCRIPTION: A Go source file for package 'a', demonstrating function calls to packages 'p' and 'q'.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_sync.txt#_snippet_3

LANGUAGE: go
CODE:
```
package a

import (
	"example.com/p"
	"example.com/q"
)

func Foo() {
	p.P()
	q.Q()
}
```

--------------------------------

TITLE: Setting up Go Environment Variables and Directories
DESCRIPTION: This snippet configures the Go environment by setting crucial environment variables like NEWGOROOT and TOOLDIR, and creating necessary directories. It utilizes symlinks to establish the GOROOT structure, pointing to the existing Go installation's source and binary directories. This setup is foundational for building and running Go programs.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/tool_build_as_needed.txt#_snippet_0

LANGUAGE: bash
CODE:
```
env NEWGOROOT=$WORK${/}goroot
env TOOLDIR=$GOROOT/pkg/tool/${GOOS}_${GOARCH}
# Use ${/} in paths we'll check for in stdout below, so they contain '\' on Windows
env NEWTOOLDIR=$NEWGOROOT${/}pkg${/}tool${/}${GOOS}_${GOARCH}
mkdir $NEWGOROOT $NEWGOROOT/bin $NEWTOOLDIR
[symlink] symlink $NEWGOROOT/src -> $GOROOT/src
[symlink] symlink $NEWGOROOT/pkg/include -> $GOROOT/pkg/include
[symlink] symlink $NEWGOROOT/bin/go -> $GOROOT/bin/go
[symlink] symlink $NEWTOOLDIR/compile$GOEXE -> $TOOLDIR/compile$GOEXE
[symlink] symlink $NEWTOOLDIR/cgo$GOEXE -> $TOOLDIR/cgo$GOEXE
[symlink] symlink $NEWTOOLDIR/link$GOEXE -> $TOOLDIR/link$GOEXE
[symlink] symlink $NEWTOOLDIR/asm$GOEXE -> $TOOLDIR/asm$GOEXE
[symlink] symlink $NEWTOOLDIR/pack$GOEXE -> $TOOLDIR/pack$GOEXE
env GOROOT=$NEWGOROOT
env TOOLDIR=$NEWTOOLDIR
```

--------------------------------

TITLE: Go testing package MainStart function
DESCRIPTION: The MainStart function in the 'testing' package is used to start tests, benchmarks, and examples. It accepts a function for test dependencies, and slices for tests, benchmarks, and examples.

SOURCE: https://github.com/golang/go/blob/master/api/except.txt#_snippet_48

LANGUAGE: go
CODE:
```
pkg testing, func MainStart(func(string, string) (bool, error), []InternalTest, []InternalBenchmark, []InternalExample) *M
```

LANGUAGE: go
CODE:
```
pkg testing, func MainStart(testDeps, []InternalTest, []InternalBenchmark, []InternalExample) *M
```

--------------------------------

TITLE: Main Execution Logic (run_go.go)
DESCRIPTION: The `run_go.go` file contains the main logic for setting up and running a Go command. It parses arguments for GOPATH and directory, sets up the environment for the child process, and executes `hello.go`.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/vendor_gopath_issue11409.txt#_snippet_1

LANGUAGE: go
CODE:
```
package main

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

func changeVolume(s string, f func(s string) string) string {
	vol := filepath.VolumeName(s)
	return f(vol) + s[len(vol):]
}

func main() {
	gopath := changeVolume(os.Args[1], strings.ToLower)
	dir := changeVolume(os.Args[2], strings.ToUpper)
	cmd := exec.Command("go", "run", "hello.go")
	cmd.Dir = dir
	cmd.Env = append(os.Environ(), "GOPATH="+gopath)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}
```

--------------------------------

TITLE: Install Specific Tool Version with go get -tool
DESCRIPTION: Installs a specific version of a tool using 'go get -tool'. It modifies the go.mod file to include the tool and its version. This is useful for pinning dependencies.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_tool.txt#_snippet_0

LANGUAGE: bash
CODE:
```
go get -tool example.com/tools/cmd/hello@v1.0.0
cmp go.mod go.mod.want
```

--------------------------------

TITLE: Error Handling for 'go get -tool all'
DESCRIPTION: Shows the error message when 'go get -tool all' is used, as this command is not supported for installing all tools. It highlights a limitation in managing tools collectively with 'all'.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_tool.txt#_snippet_5

LANGUAGE: bash
CODE:
```
! go get -tool all
stderr 'go get -tool does not work with "all"'
```

--------------------------------

TITLE: Go testing MainStart Function
DESCRIPTION: Shows how to initiate the Go testing framework, including dependency setup and test/benchmark/example execution.

SOURCE: https://github.com/golang/go/blob/master/api/go1.8.txt#_snippet_90

LANGUAGE: go
CODE:
```
func MainStart(testDeps, []InternalTest, []InternalBenchmark, []InternalExample) *M
```

--------------------------------

TITLE: Populate go.sum and List Import Path (GO=off)
DESCRIPTION: Demonstrates populating the go.sum file using 'go get' and then listing the import path of the 'math' package with GO111MODULE set to off.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_list_dir.txt#_snippet_0

LANGUAGE: go
CODE:
```
env GO111MODULE=off
go get
go list -f '{{.ImportPath}}' $GOROOT/src/math
stdout ^math$
```

--------------------------------

TITLE: Build and Run Go Program on Windows
DESCRIPTION: This snippet details the commands to build and execute a Go program (`run_go.go`) on a Windows environment. It sets up the necessary environment variables and executes the compiled program, which in turn runs another Go program (`hello.go`) from a vendored directory.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/vendor_gopath_issue11409.txt#_snippet_0

LANGUAGE: bash
CODE:
```
#!/bin/bash
GOOS=windows go build run_go.go
exec ./run_go$GOEXE $GOPATH $GOPATH/src/vend/hello
stdout 'hello, world'
```

--------------------------------

TITLE: Go Source Code (Example B)
DESCRIPTION: A Go source file for package 'b', demonstrating function calls to packages 'p' and 'q'.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_sync.txt#_snippet_6

LANGUAGE: go
CODE:
```
package b

import (
	"example.com/p"
	"example.com/q"
)

func Foo() {
	p.P()
	q.Q()
}
```

--------------------------------

TITLE: Build and Execute a Simple Go Program
DESCRIPTION: This snippet shows the basic commands to build and execute a Go program. It compiles the 'hello.go' file and then runs the resulting binary.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_static.txt#_snippet_0

LANGUAGE: bash
CODE:
```
go build
exec ./hello
```

--------------------------------

TITLE: Get Install Path for Standard Command
DESCRIPTION: Retrieves the installation target path for a standard Go command (cmd/pack) using the `go list` command with a custom format string. The output shows the expected directory structure, including GOOS and GOARCH.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/install_cross_gobin.txt#_snippet_3

LANGUAGE: shell
CODE:
```
go list -f '{{.Target}}'  cmd/pack
stdout ${GOROOT}[/\\]pkg[[/\\]]tool[[/\\]]${GOOS}_${GOARCH}[[/\\]]pack$
```

--------------------------------

TITLE: Go Get: Wildcard Update for Modules and Packages
DESCRIPTION: This snippet demonstrates how a wildcard pattern in 'go get' can update both modules and their packages to a specified version. It shows fetching all packages under 'example.net' with a specific version and then fetching without a version to get the latest.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_split.txt#_snippet_5

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
go get example.net/split/nested@v0.0.0

go get example.net/...

```

LANGUAGE: bash
CODE:
```
go list -m all
stdout '^example.net/split v0.3.0 '
stdout '^example.net/split/nested v0.2.0 '
```

--------------------------------

TITLE: Module Q Test Implementation
DESCRIPTION: The 'q_test.go' file for package 'q' imports 'example.com/s'. This demonstrates dependency management within test files.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_all.txt#_snippet_32

LANGUAGE: go
CODE:
```
package q_test
import _ "example.com/s"
```

--------------------------------

TITLE: Get Specific Go Module Version
DESCRIPTION: Retrieves and installs a specific version of a module. This command also updates the go.mod file.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/version_replace.txt#_snippet_1

LANGUAGE: go
CODE:
```
go get example.com/printversion@v0.1.0
```

--------------------------------

TITLE: Build Go Project and Manage Cache
DESCRIPTION: This snippet demonstrates building a Go project, ensuring the runtime/cgo package is cached, and then executing the build with verbose output. It highlights the importance of the build cache for dependencies.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_dash_x.txt#_snippet_0

LANGUAGE: shell
CODE:
```
env GOCACHE=$WORK/tmp/cache
go build runtime/cgo
go build -x -o main ./...
```

--------------------------------

TITLE: Use Wildcards with go get -tool
DESCRIPTION: Installs tools from a directory using a wildcard pattern like './cmd/...'. This allows for managing multiple tools within a package structure. Attempting to use '@none' with wildcards results in an error.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_tool.txt#_snippet_4

LANGUAGE: bash
CODE:
```
go get -tool ./cmd/...
cmp go.mod go.mod.wildcard
! go get -tool ./cmd/...@none
stderr 'can''t request explicit version "none" of path "./cmd/..." in main module'
```

--------------------------------

TITLE: Basic Go Program
DESCRIPTION: A minimal Go program that defines the main package and an empty main function.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/install_cross_gobin.txt#_snippet_4

LANGUAGE: go
CODE:
```
package main

func main() {}
```

--------------------------------

TITLE: Golang Project Setup with Vendor Directory
DESCRIPTION: This snippet demonstrates the creation of a vendor directory, setting up symlinks for module paths, and copying Go source files. It configures the environment variables for GOPATH and then executes `go list` to show project dependencies.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/list_symlink_vendor_issue15201.txt#_snippet_0

LANGUAGE: shell
CODE:
```
env GO111MODULE=off

mkdir $WORK/tmp/gopath/src/x/y/_vendor/src/x
symlink $WORK/tmp/gopath/src/x/y/_vendor/src/x/y -> ../../../
mkdir $WORK/tmp/gopath/src/x/y/_vendor/src/x/y/w
cp w.go $WORK/tmp/gopath/src/x/y/w/w.go
symlink $WORK/tmp/gopath/src/x/y/w/vendor -> ../_vendor/src
mkdir $WORK/tmp/gopath/src/x/y/_vendor/src/x/y/z
cp z.go $WORK/tmp/gopath/src/x/y/z/z.go

env GOPATH=$WORK/tmp/gopath/src/x/y/_vendor${:}$WORK/tmp/gopath
cd $WORK/tmp/gopath/src
go list ./...
```

--------------------------------

TITLE: Building a Go executable and placing it directly in a directory
DESCRIPTION: Creates a 'bin' directory, builds 'x.go' into it as 'bin/x', verifies its execution, and then removes the 'bin' directory.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_output.txt#_snippet_5

LANGUAGE: bash
CODE:
```
! exists bin
mkdir bin
go build -o bin x.go
exists -exec bin/x$GOEXE
rm bin
```

--------------------------------

TITLE: Go Get: Update Package in Build List
DESCRIPTION: This example shows how 'go get' updates an existing package in the build list when a new version is specified. It demonstrates fetching a specific patch version of a nested package and verifies the module list afterwards.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_split.txt#_snippet_0

LANGUAGE: bash
CODE:
```
cp go.mod go.mod.orig
go get example.net/split/nested@patch
go list -m all
stdout '^example.net/split v0.2.1 '
! stdout '^example.net/split/nested'
```

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod

go get example.net/split/nested/...

```

--------------------------------

TITLE: Golang Main Application (main.go)
DESCRIPTION: A simple Golang program that imports the 'C' package (likely for cgo) and prints 'hello\n' to the console.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_dash_x.txt#_snippet_3

LANGUAGE: go
CODE:
```
package main

import "C"

func main() {
	print("hello\n")
}
```

--------------------------------

TITLE: Go For Clause Variable Scoping (Go 1.22+)
DESCRIPTION: Demonstrates the variable scoping behavior in Go 'for' loops starting from version 1.22, where each iteration gets its own distinct variable. This example highlights the output difference compared to pre-1.22 versions.

SOURCE: https://github.com/golang/go/blob/master/doc/go_spec.html#_snippet_170

LANGUAGE: Go
CODE:
```
var prints []func()
for i := 0; i < 5; i++ {
	prints = append(prints, func() { println(i) })
	i++
}
for _, p := range prints {
	p()
}
```

--------------------------------

TITLE: Preview Local Website with Release Notes
DESCRIPTION: Command to run a local instance of the Go website to preview `next` release notes content. It requires the `golang.org/x/website` module and specifies the Go root directory.

SOURCE: https://github.com/golang/go/blob/master/doc/README.md#_snippet_0

LANGUAGE: bash
CODE:
```
go run golang.org/x/website/cmd/golangorg@latest -goroot=..
```

--------------------------------

TITLE: Wildcard Package Installation with Go
DESCRIPTION: Demonstrates installing packages using wildcards. It ensures that wildcards only match main packages and handles scenarios with non-main packages or no matching packages.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_install_pkg_version.txt#_snippet_11

LANGUAGE: bash
CODE:
```
# Wildcards should match only main packages. This module has a non-main package
# with an error, so we'll know if that gets built.
mkdir tmp
cd tmp
go mod init m
go get example.com/cmd@v1.0.0
! go build example.com/cmd/...
stderr 'err[/\]err.go:3:9: undefined: DoesNotCompile( .*)?$
cd ..

go install example.com/cmd/...@v1.0.0
exists $GOPATH/bin/a$GOEXE
exists $GOPATH/bin/b$GOEXE
rm $GOPATH/bin

# If a wildcard matches no packages, we should see a warning.
! go install example.com/cmd/nomatch...@v1.0.0
stderr '^go: example.com/cmd/nomatch\.\.\.@v1.0.0: module example.com/cmd@v1.0.0 found, but does not contain packages matching example.com/cmd/nomatch\.\.\.$'
go install example.com/cmd/a@v1.0.0 example.com/cmd/nomatch...@v1.0.0
stderr '^go: warning: "example.com/cmd/nomatch\.\.\." matched no packages$'

# If a wildcard matches only non-main packages, we should see a different warning.
go install example.com/cmd/err...@v1.0.0
stderr '^go: warning: "example.com/cmd/err\.\.\." matched only non-main packages$'
```

--------------------------------

TITLE: Example Module 'q' (v1.1.0) Go Module Definition
DESCRIPTION: The go.mod file for version 1.1.0 of module 'q'. It declares dependencies on 'example.com/w' and 'example.com/z', showcasing multiple direct dependencies in a vendored setup.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_vendor_prune_all.txt#_snippet_14

LANGUAGE: go
CODE:
```
module example.com/q

require example.com/w v1.0.0
require example.com/z v1.1.0

go 1.18

```

--------------------------------

TITLE: Go Get Package Path Examples
DESCRIPTION: Illustrates `go get` behavior with package paths, including those with `.go` suffixes and version specifiers. Arguments are treated as packages or patterns with versions, not source files. It shows successful `go get` operations with or without versions specified.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_trailing_slash.txt#_snippet_1

LANGUAGE: bash
CODE:
```
go get example.com/dotgo.go
```

LANGUAGE: bash
CODE:
```
go get example.com/dotgo.go/
```

LANGUAGE: bash
CODE:
```
go get example.com/dotgo.go@v1.0.0
```

LANGUAGE: bash
CODE:
```
go get example.com/dotgo.go/@v1.0.0
```

--------------------------------

TITLE: List All Module Dependencies
DESCRIPTION: Lists all direct and indirect module requirements for the current project. This command is useful for verifying the current state of dependencies after modifications.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_changes.txt#_snippet_3

LANGUAGE: bash
CODE:
```
go list -m all
```

--------------------------------

TITLE: Install Directory Package (GO111MODULE=on)
DESCRIPTION: Demonstrates installing a package using a directory path when GO111MODULE is enabled. It includes steps for setting up a temporary module and handling read-only mode.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_install_pkg_version.txt#_snippet_5

LANGUAGE: bash
CODE:
```
env GO111MODULE=on
go mod download rsc.io/fortune@v1.0.0
! go install $GOPATH/pkg/mod/rsc.io/fortune@v1.0.0
stderr '^go: go.mod file not found in current directory or any parent directory; see ' go help modules''$'
'
! go install ../pkg/mod/rsc.io/fortune@v1.0.0
stderr '^go: go.mod file not found in current directory or any parent directory; see ' go help modules''$'
'
mkdir tmp
cd tmp
go mod init tmp
go mod edit -require=rsc.io/fortune@v1.0.0
! go install -mod=readonly $GOPATH/pkg/mod/rsc.io/fortune@v1.0.0
stderr '^missing go.sum entry for module providing package rsc.io/fortune; to add:
	go mod download rsc.io/fortune$'
! go install -mod=readonly ../../pkg/mod/rsc.io/fortune@v1.0.0
stderr '^missing go.sum entry for module providing package rsc.io/fortune; to add:
	go mod download rsc.io/fortune$'
go get rsc.io/fortune@v1.0.0
go install -mod=readonly $GOPATH/pkg/mod/rsc.io/fortune@v1.0.0
exists $GOPATH/bin/fortune$GOEXE
cd ..
rm tmp
rm $GOPATH/bin
env GO111MODULE=auto
```

--------------------------------

TITLE: Initialize Git Repository and Set Author
DESCRIPTION: Sets up environment variables for Git author and committer information and initializes a new Git repository.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/vcstest/git/tagtests.txt#_snippet_0

LANGUAGE: shell
CODE:
```
env GIT_AUTHOR_NAME='Jay Conrod'
env GIT_AUTHOR_EMAIL='jayconrod@google.com'
env GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME
env GIT_COMMITTER_EMAIL=$GIT_AUTHOR_EMAIL

git init
```

--------------------------------

TITLE: Go Module File Example
DESCRIPTION: This is an example content of a go.mod file, specifying the module path and the required Go version.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_get_toolchain.txt#_snippet_1

LANGUAGE: go.mod
CODE:
```
module m
go 1.1
```

--------------------------------

TITLE: Get with Vendor Flag (Error)
DESCRIPTION: Attempts to use the '-mod=vendor' flag with the 'go get' command. This flag is not supported by 'go get' and will result in an error.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_getmode_vendor.txt#_snippet_4

LANGUAGE: bash
CODE:
```
! go get -mod=vendor -u
stderr 'flag provided but not defined: -mod'
```

--------------------------------

TITLE: Module Q Implementation
DESCRIPTION: The 'q.go' file defines the 'q' package and imports 'example.com/r'. This shows a direct dependency relationship.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_all.txt#_snippet_31

LANGUAGE: go
CODE:
```
package q
import _ "example.com/r"
```

--------------------------------

TITLE: Cross-Compile and Install (Implicit GOBIN)
DESCRIPTION: Cross-compiles and installs a Go command for a specific architecture (386) and operating system (linux). Uses the implicit GOBIN setting, which defaults to $GOPATH/bin. It demonstrates checking for the existence of the installed binary in a subdirectory structure reflecting the OS and architecture.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/install_cross_gobin.txt#_snippet_1

LANGUAGE: shell
CODE:
```
env GOARCH=386
[GOARCH:386] env GOARCH=amd64
env GOOS=linux
go install mycmd
exists $GOPATH/bin/linux_$GOARCH/mycmd
```

--------------------------------

TITLE: Go Module Initialization: 'gopkg.in' Domain Rules
DESCRIPTION: Illustrates Go module initialization for the 'gopkg.in' domain, highlighting the mandatory '.vN' suffix requirement for all module paths starting with 'gopkg.in/'. This ensures proper versioning for packages hosted on this domain.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_init_invalid_major.txt#_snippet_2

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/pkg
stderr '(?s)^go: invalid module path "gopkg.in/pkg": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg/v0
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg/v0": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg/v1
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg/v1": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg/v2
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg/v2": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v2$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg.v
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg.v": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg.v0.1
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg.v0.1": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg.v.1
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg.v.1": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg.v01
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg.v01": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v1$'
```

LANGUAGE: bash
CODE:
```
! go mod init gopkg.in/user/pkg.v.2.3
stderr '(?s)^go: invalid module path "gopkg.in/user/pkg.v.2.3": module paths beginning with gopkg.in/ must always have a major version suffix in the form of .vN(.*)go mod init gopkg.in/user/pkg.v2$'
```

--------------------------------

TITLE: Go Get Default Behavior
DESCRIPTION: Shows that the default 'go get' command behaves like 'go get @upgrade', maintaining the current pseudoverison and not downgrading.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_upgrade_pseudo.txt#_snippet_3

LANGUAGE: shell
CODE:
```
go get example.com/pseudoupgrade
go list -m all
stdout '^example.com/pseudoupgrade v0.1.1-0.20190429073117-b5426c86b553$'
```

--------------------------------

TITLE: Run Golang Application
DESCRIPTION: Command to set the GO111MODULE environment variable, change directory to the application's vendored path, and execute the main Go program.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/run_vendor.txt#_snippet_0

LANGUAGE: shell
CODE:
```
env GO111MODULE=off
cd vend/hello
go run hello.go
stdout 'hello, world'
```

--------------------------------

TITLE: Go Module Initialization Example
DESCRIPTION: Shows the `go.mod` file content for different modules, including requirements and module definitions.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_tidy.txt#_snippet_4

LANGUAGE: go
CODE:
```
module w
```

LANGUAGE: go
CODE:
```
module x
require w.1 v1.1.0
require z.1 v1.1.0
```

LANGUAGE: go
CODE:
```
module y
require z.1 v1.2.0
```

LANGUAGE: go
CODE:
```
module z
```

LANGUAGE: go
CODE:
```
module triv
```

--------------------------------

TITLE: Get Non-Excluded Go Module Version
DESCRIPTION: Shows successfully getting a module version that is not excluded.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_query_exclude.txt#_snippet_4

LANGUAGE: bash
CODE:
```
env GO111MODULE=on
# get non-excluded version
cp go.exclude.mod.orig go.exclude.mod
go get -modfile=go.exclude.mod rsc.io/quote@v1.5.1
```

--------------------------------

TITLE: Go Program: Hello World
DESCRIPTION: A simple Go program that prints 'hello!' to the console. This is the main entry point for the executable.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/clean_binary.txt#_snippet_6

LANGUAGE: go
CODE:
```
package main

import "fmt"

func main() {
	fmt.Println("hello!")
}
```

--------------------------------

TITLE: Go: Get incomplete module with work query
DESCRIPTION: Tests 'go get' with an incomplete module using a 'work' query. It removes go.sum, runs 'go get work', and then compares the go.mod and go.sum files.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_2

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
rm go.sum
go get work
cmp go.mod go.mod.want
cmp go.sum go.sum.want
```

--------------------------------

TITLE: Basic Git Workflow: Init, Add, Commit, Branch, Tag
DESCRIPTION: Demonstrates a common Git workflow: initializing a repository, adding files, committing changes, renaming the main branch, and creating a tag.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/vcstest/git/issue47650.txt#_snippet_1

LANGUAGE: bash
CODE:
```
git init
git add cmd
git commit -m 'add cmd/issue47650'
git branch -m main
git tag v0.1.0
git add go.mod
git commit -m 'add go.mod'
```

--------------------------------

TITLE: Go: Get incomplete module with path query
DESCRIPTION: Tests 'go get' with an incomplete module using a path query that can be resolved (e.g., 'rsc.io/quote'). It removes go.sum, runs 'go get rsc.io/quote', and compares the go.mod and go.sum files.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_3

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
rm go.sum
go get rsc.io/quote
cmp go.mod go.mod.want.path_query
cmp go.sum go.sum.want
```

--------------------------------

TITLE: Run Tests and Benchmarks with MainStart (Go Testing)
DESCRIPTION: The `MainStart` function from the `testing` package is used to initiate the execution of tests, benchmarks, and fuzz targets within a Go program. It accepts slices of test dependencies, internal tests, benchmarks, fuzz targets, and examples.

SOURCE: https://github.com/golang/go/blob/master/api/go1.18.txt#_snippet_49

LANGUAGE: go
CODE:
```
func MainStart(testDeps, []InternalTest, []InternalBenchmark, []InternalFuzzTarget, []InternalExample) *M
```

--------------------------------

TITLE: Go: Get incomplete module with wildcard query
DESCRIPTION: Tests 'go get' with an incomplete module using a wildcard query ('./...'). It removes go.sum, runs 'go get ./...', and then compares the go.mod and go.sum files.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_1

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
rm go.sum
go get ./...
cmp go.mod go.mod.want
cmp go.sum go.sum.want
```

--------------------------------

TITLE: Configure Git Author and Initial Commit
DESCRIPTION: Sets environment variables for Git author and committer information, initializes a Git repository, adds Go module and source files, and creates an initial commit.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/vcstest/git/v3pkg.txt#_snippet_0

LANGUAGE: shell
CODE:
```
env GIT_AUTHOR_NAME='Bryan C. Mills'
env GIT_AUTHOR_EMAIL='bcmills@google.com'
env GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME
env GIT_COMMITTER_EMAIL=$GIT_AUTHOR_AUTHOR_EMAIL

git init

env GIT_AUTHOR_DATE=2019-07-15T13:59:34-04:00
git add go.mod v3pkg.go
git commit -a -m 'all: add go.mod with v3 path'
```

--------------------------------

TITLE: Go: Get incomplete module with local query
DESCRIPTION: Tests 'go get' with an incomplete module using a local query. It copies the original go.mod, runs 'go get', and then compares the resulting go.mod and go.sum files with their expected versions.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_0

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
go get
cmp go.mod go.mod.want
cmp go.sum go.sum.want
```

--------------------------------

TITLE: Go Module Configuration (Example A)
DESCRIPTION: Specifies the module path, Go version, and dependencies for module 'a'. Includes 'require' for direct dependencies and 'replace' for local module path overrides.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_sync.txt#_snippet_1

LANGUAGE: go
CODE:
```
go 1.18

module example.com/a

require (
	example.com/p v1.0.0
	example.com/q v1.1.0
	example.com/r v1.0.0
)

replace (
	example.com/p => ../p
	example.com/q => ../q
	example.com/r => ../r
)
```

--------------------------------

TITLE: Go Get: Update Module and Nested Packages
DESCRIPTION: This example illustrates updating a module to a specific version and also updating nested packages within that module. It shows fetching a module and its nested packages with a shared version, and then verifying the changes in the module list.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_split.txt#_snippet_4

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod

go get example.net/split@v0.3.0 example.net/split/nested@v0.1.0
go list -m all
stdout '^example.net/split v0.3.0 '
stdout '^example.net/split/nested v0.1.0 '
```

--------------------------------

TITLE: Package 'main' Implementation
DESCRIPTION: The main package includes functions 'MFunc' and 'M2Func', along with an init function and the primary 'main' function. It demonstrates usage of packages 'a' and 'b' and prints results to the console.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/cover_coverpkg_with_init.txt#_snippet_8

LANGUAGE: go
CODE:
```
package main

import (
	"M/a"
	"M/b"
)

func MFunc() string {
	return "42"
}

func M2Func() int {
	return a.AFunc() + b.BFunc()
}

func init() {
	println("package 'main' init")
}

func main() {
	println(a.AFunc() + b.BFunc())
}
```

--------------------------------

TITLE: Go: Get workspace module with unresolvable path query
DESCRIPTION: Tests 'go get' with a path query to a workspace module that cannot be resolved. It checks that an error is returned indicating the module was not found.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_4

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
rm go.sum
! go get example.com/n
stderr 'module example.com@upgrade found \(v1.0.0\), but does not contain package example.com/n'
```

--------------------------------

TITLE: Execute and Verify Go Application
DESCRIPTION: This section details the execution of the compiled Go program and verification of its output. It includes steps to copy output and error streams to files, execute a test script, and compare the actual output with a reference file.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_dash_x.txt#_snippet_1

LANGUAGE: shell
CODE:
```
cp stderr commands.txt
cat header.txt commands.txt
cp stdout test.sh

exec ./main
cmp stderr hello.txt
rm ./main

exec /usr/bin/env bash -x test.sh
exec ./main
cmp stderr hello.txt
```

--------------------------------

TITLE: Remove Dependency with 'go get'
DESCRIPTION: Removes a Go module dependency from the project. 'go get' outputs messages for the removed requirement and any affected explicit dependencies. Changes to indirect dependencies are not shown.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_changes.txt#_snippet_1

LANGUAGE: bash
CODE:
```
go get rsc.io/sampler@none
```

--------------------------------

TITLE: Go: Get incomplete module with all query
DESCRIPTION: Tests 'go get' with an incomplete module using an 'all' query. It removes go.sum, runs 'go get all', and compares the go.mod and go.sum files, noting that 'all' may load a different graph.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_workspace_incomplete.txt#_snippet_5

LANGUAGE: bash
CODE:
```
cp go.mod.orig go.mod
rm go.sum
go get all
cmp go.mod go.mod.want.all
cmp go.sum go.sum.want.all
```

--------------------------------

TITLE: Go Example Code (example.go)
DESCRIPTION: A simple Go package example that imports another module. It demonstrates package declaration and import statements.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_doc_path.txt#_snippet_1

LANGUAGE: go
CODE:
```
package example

import _ "example.com/p"
```

--------------------------------

TITLE: Go Module Initialization: Valid Paths
DESCRIPTION: Initializes a new Go module with a valid path. This is the standard way to start a new module. The command sets up the go.mod file.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_init_invalid_major.txt#_snippet_0

LANGUAGE: bash
CODE:
```
env GO111MODULE=on
env GOFLAGS=-mod=mod

! go mod init example.com/user/repo/v2
stderr '(?s)^go: invalid module path "example.com/user/repo/v0": major version suffixes must be in the form of /vN and are only allowed for v2 or later(.*)go mod init example.com/user/repo/v2$'
```

--------------------------------

TITLE: Go Module Configuration (Package Q)
DESCRIPTION: Defines the module path and Go version for the 'q' module.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_sync.txt#_snippet_9

LANGUAGE: go
CODE:
```
go 1.18

module example.com/q
```

--------------------------------

TITLE: Example Module 'w' Test File
DESCRIPTION: A test file for module 'w'. It includes an underscore import of 'example.com/x', indicating that the test relies on 'x' for its setup or side effects.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_vendor_prune_all.txt#_snippet_20

LANGUAGE: go
CODE:
```
package w

import _ "example.com/x"

```

--------------------------------

TITLE: Go Get: Wildcard with Empty Module Resolution
DESCRIPTION: This snippet demonstrates how a wildcard can resolve to an empty module with the same prefix, even if it contains no packages. It shows fetching all 'example.net' packages with '@none', then fetching a specific nested package, and verifying the module list.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_split.txt#_snippet_7

LANGUAGE: bash
CODE:
```
go get example.net/...

go get example.net/split/...
go list -m all
stdout '^example.net/split v0.1.0 '
```

--------------------------------

TITLE: Go Main Package Example
DESCRIPTION: A simple Go program that prints the string 'hello' to standard output.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/build_cache_trimpath.txt#_snippet_2

LANGUAGE: go
CODE:
```
package main

func main() { println("hello") }
```

--------------------------------

TITLE: Get Go Module Query with Exclusions
DESCRIPTION: Illustrates getting module versions using a range specifier when an exclusion is present.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_query_exclude.txt#_snippet_5

LANGUAGE: bash
CODE:
```
env GO111MODULE=on
# get query with excluded version
cp go.exclude.mod.orig go.exclude.mod
go get -modfile=go.exclude.mod rsc.io/quote@>=v1.5
go list -modfile=go.exclude.mod -m ...quote
```

--------------------------------

TITLE: Initialize Go Workspace
DESCRIPTION: Initializes a new Go workspace with specified module directories. It creates a `go.work` file to manage the workspace.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work.txt#_snippet_0

LANGUAGE: bash
CODE:
```
go work init ./a ./b
```

--------------------------------

TITLE: Get Excluded Go Module Version
DESCRIPTION: Demonstrates attempting to get a module version that is excluded, showing the expected error.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_query_exclude.txt#_snippet_3

LANGUAGE: bash
CODE:
```
env GO111MODULE=on
# get excluded version
cp go.exclude.mod go.exclude.mod.orig
! go get -modfile=go.exclude.mod rsc.io/quote@v1.5.0
```

--------------------------------

TITLE: Initialize Go Workspace
DESCRIPTION: Initializes a Go workspace with the specified Go version and includes local modules 'a' and 'b'. This command sets up the workspace configuration.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/work_sync_relevant_dependency.txt#_snippet_0

LANGUAGE: go
CODE:
```
go 1.18

use (
	./a
	./b
)
```

--------------------------------

TITLE: Go Get Default with Newer Pseudoverison
DESCRIPTION: Illustrates that the default 'go get' command maintains the newer pseudoverison and does not downgrade.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_upgrade_pseudo.txt#_snippet_8

LANGUAGE: shell
CODE:
```
go get example.com/pseudoupgrade
go list -m -u all
stdout '^example.com/pseudoupgrade v0.0.0-20190430073000-30950c05d534$'
```

--------------------------------

TITLE: Go Get with Upgrade Keyword
DESCRIPTION: Tests that 'go get @upgrade' respects the current pseudoverison and does not downgrade to a tagged version.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_get_upgrade_pseudo.txt#_snippet_2

LANGUAGE: shell
CODE:
```
go get example.com/pseudoupgrade@upgrade
go list -m all
stdout '^example.com/pseudoupgrade v0.1.1-0.20190429073117-b5426c86b553$'
```

--------------------------------

TITLE: List all packages with specific patterns in Go
DESCRIPTION: Lists all packages, packages in the main module, and packages starting with a specific prefix, using the 'go list' command with custom formatting. It demonstrates how different patterns like 'all', '... example.com/m/...', './...', and './xyz...' affect the output.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/mod_patterns.txt#_snippet_0

LANGUAGE: bash
CODE:
```
env GO111MODULE=on
cd m
go list -f '{{.ImportPath}}: {{.Match}}' all ... example.com/m/... ./... ./xyz...
```

--------------------------------

TITLE: Install mtime and sametime programs
DESCRIPTION: Installs the 'mtime' and 'sametime' Go programs into the GOBIN directory. These programs are used later in the tests to get file modification times and compare timestamps.

SOURCE: https://github.com/golang/go/blob/master/src/cmd/go/testdata/script/test_race_install_cgo.txt#_snippet_0

LANGUAGE: shell
CODE:
```
env GOBIN=$WORK/bin
go install m/mtime m/sametime
```