Golang命令行工具 go env

go env ：查看go环境变量

C:\Program Files\Go\src>go env
set GO111MODULE=on
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\qingshuic\AppData\Local\go-build
set GOENV=C:\Users\qingshuic\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\qingshuic\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\qingshuic\go
set GOPRIVATE=
set GOPROXY=https://goproxy.cn,direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.18.1
set GCCGO=gccgo
set GOAMD64=v1
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=C:\Program Files\Go\src\go.mod
set GOWORK=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\tmp\go-
build3432994836=/tmp/go-build -gno-record-gcc-switches

go help env ：查看 go env 帮助命令

C:\Program Files\Go\src>go help env
usage: go env [-json] [-u] [-w] [var ...]

Env prints Go environment information.

By default env prints information as a shell script
(on Windows, a batch file). If one or more variable
names is given as arguments, env prints the value of
each named variable on its own line.

The -json flag prints the environment in JSON format
instead of as a shell script.

The -u flag requires one or more arguments and unsets
the default setting for the named environment variables,
if one has been set with 'go env -w'.

The -w flag requires one or more arguments of the
form NAME=VALUE and changes the default settings
of the named environment variables to the given values.

For more about environment variables, see 'go help environment'.

go help environment 环境变量帮助

C:\Program Files\Go\src>go help environment
The go command and the tools it invokes consult environment variables
for configuration. If an environment variable is unset, the go command
uses a sensible default setting. To see the effective setting of the
variable <NAME>, run 'go env <NAME>'. To change the default setting,
run 'go env -w <NAME>=<VALUE>'. Defaults changed using 'go env -w'
are recorded in a Go environment configuration file stored in the
per-user configuration directory, as reported by os.UserConfigDir.
The location of the configuration file can be changed by setting
the environment variable GOENV, and 'go env GOENV' prints the
effective location, but 'go env -w' cannot change the default location.
See 'go help env' for details.

General-purpose environment variables:

GO111MODULE
Controls whether the go command runs in module-aware mode or GOPATH mode.
May be "off", "on", or "auto".
See https://golang.org/ref/mod#mod-commands.
GCCGO
The gccgo command to run for 'go build -compiler=gccgo'.
GOARCH
The architecture, or processor, for which to compile code.
Examples are amd64, 386, arm, ppc64.
GOBIN
The directory where 'go install' will install a command.
GOCACHE
The directory where the go command will store cached
information for reuse in future builds.
GOMODCACHE
The directory where the go command will store downloaded modules.
GODEBUG
Enable various debugging facilities. See 'go doc runtime'
for details.
GOENV
The location of the Go environment configuration file.
Cannot be set using 'go env -w'.
Setting GOENV=off in the environment disables the use of the
default configuration file.
GOFLAGS
A space-separated list of -flag=value settings to apply
to go commands by default, when the given flag is known by
the current command. Each entry must be a standalone flag.
Because the entries are space-separated, flag values must
not contain spaces. Flags listed on the command line
are applied after this list and therefore override it.
GOINSECURE
Comma-separated list of glob patterns (in the syntax of Go's path.Match)
of module path prefixes that should always be fetched in an insecure
manner. Only applies to dependencies that are being fetched directly.
GOINSECURE does not disable checksum database validation. GOPRIVATE or
GONOSUMDB may be used to achieve that.
GOOS
The operating system for which to compile code.
Examples are linux, darwin, windows, netbsd.
GOPATH
For more details see: 'go help gopath'.
GOPROXY
URL of Go module proxy. See https://golang.org/ref/mod#environment-variables
and https://golang.org/ref/mod#module-proxy for details.
GOPRIVATE, GONOPROXY, GONOSUMDB
Comma-separated list of glob patterns (in the syntax of Go's path.Match)
of module path prefixes that should always be fetched directly
or that should not be compared against the checksum database.
See https://golang.org/ref/mod#private-modules.
GOROOT
The root of the go tree.
GOSUMDB
The name of checksum database to use and optionally its public key and
URL. See https://golang.org/ref/mod#authenticating.
GOTMPDIR
The directory where the go command will write
temporary source files, packages, and binaries.
GOVCS
Lists version control commands that may be used with matching servers.
See 'go help vcs'.
GOWORK
In module aware mode, use the given go.work file as a workspace file.
By default or when GOWORK is "auto", the go command searches for a
file named go.work in the current directory and then containing directories
until one is found. If a valid go.work file is found, the modules
specified will collectively be used as the main modules. If GOWORK
is "off", or a go.work file is not found in "auto" mode, workspace
mode is disabled.

Environment variables for use with cgo:

AR
The command to use to manipulate library archives when
building with the gccgo compiler.
The default is 'ar'.
CC
The command to use to compile C code.
CGO_ENABLED
Whether the cgo command is supported. Either 0 or 1.
CGO_CFLAGS
Flags that cgo will pass to the compiler when compiling
C code.
CGO_CFLAGS_ALLOW
A regular expression specifying additional flags to allow
to appear in #cgo CFLAGS source code directives.
Does not apply to the CGO_CFLAGS environment variable.
CGO_CFLAGS_DISALLOW
A regular expression specifying flags that must be disallowed
from appearing in #cgo CFLAGS source code directives.
Does not apply to the CGO_CFLAGS environment variable.
CGO_CPPFLAGS, CGO_CPPFLAGS_ALLOW, CGO_CPPFLAGS_DISALLOW
Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
but for the C preprocessor.
CGO_CXXFLAGS, CGO_CXXFLAGS_ALLOW, CGO_CXXFLAGS_DISALLOW
Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
but for the C++ compiler.
CGO_FFLAGS, CGO_FFLAGS_ALLOW, CGO_FFLAGS_DISALLOW
Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
but for the Fortran compiler.
CGO_LDFLAGS, CGO_LDFLAGS_ALLOW, CGO_LDFLAGS_DISALLOW
Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
but for the linker.
CXX
The command to use to compile C++ code.
FC
The command to use to compile Fortran code.
PKG_CONFIG
Path to pkg-config tool.

Architecture-specific environment variables:

GOARM
For GOARCH=arm, the ARM architecture for which to compile.
Valid values are 5, 6, 7.
GO386
For GOARCH=386, how to implement floating point instructions.
Valid values are sse2 (default), softfloat.
GOAMD64
For GOARCH=amd64, the microarchitecture level for which to compile.
Valid values are v1 (default), v2, v3, v4.
See https://golang.org/wiki/MinimumRequirements#amd64
GOMIPS
For GOARCH=mips{,le}, whether to use floating point instructions.
Valid values are hardfloat (default), softfloat.
GOMIPS64
For GOARCH=mips64{,le}, whether to use floating point instructions.
Valid values are hardfloat (default), softfloat.
GOPPC64
For GOARCH=ppc64{,le}, the target ISA (Instruction Set Architecture).
Valid values are power8 (default), power9.
GOWASM
For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use.
Valid values are satconv, signext.

Special-purpose environment variables:

GCCGOTOOLDIR
If set, where to find gccgo tools, such as cgo.
The default is based on how gccgo was configured.
GOEXPERIMENT
Comma-separated list of toolchain experiments to enable or disable.
The list of available experiments may change arbitrarily over time.
See src/internal/goexperiment/flags.go for currently valid values.
Warning: This variable is provided for the development and testing
of the Go toolchain itself. Use beyond that purpose is unsupported.
GOROOT_FINAL
The root of the installed Go tree, when it is
installed in a location other than where it is built.
File names in stack traces are rewritten from GOROOT to
GOROOT_FINAL.
GO_EXTLINK_ENABLED
Whether the linker should use external linking mode
when using -linkmode=auto with code that uses cgo.
Set to 0 to disable external linking mode, 1 to enable it.
GIT_ALLOW_PROTOCOL
Defined by Git. A colon-separated list of schemes that are allowed
to be used with git fetch/clone. If set, any scheme not explicitly
mentioned will be considered insecure by 'go get'.
Because the variable is defined by Git, the default value cannot
be set using 'go env -w'.

Additional information available from 'go env' but not read from the environment:

GOEXE
The executable file name suffix (".exe" on Windows, "" on other systems).
GOGCCFLAGS
A space-separated list of arguments supplied to the CC command.
GOHOSTARCH
The architecture (GOARCH) of the Go toolchain binaries.
GOHOSTOS
The operating system (GOOS) of the Go toolchain binaries.
GOMOD
The absolute path to the go.mod of the main module.
If module-aware mode is enabled, but there is no go.mod, GOMOD will be
os.DevNull ("/dev/null" on Unix-like systems, "NUL" on Windows).
If module-aware mode is disabled, GOMOD will be the empty string.
GOTOOLDIR
The directory where the go tools (compile, cover, doc, etc...) are installed.
GOVERSION
The version of the installed Go tree, as reported by runtime.Version.

go env xxx ：查看指定配置

C:\Program Files\Go\src>go env GOVERSION
go1.18.1

go env -json : 以json格式输出配置

C:\Program Files\Go\src>go env -json
{
        "AR": "ar",
        "CC": "gcc",
        "CGO_CFLAGS": "-g -O2",
        "CGO_CPPFLAGS": "",
        "CGO_CXXFLAGS": "-g -O2",
        "CGO_ENABLED": "1",
        "CGO_FFLAGS": "-g -O2",
        "CGO_LDFLAGS": "-g -O2",
        "CXX": "g++",
        "GCCGO": "gccgo",
        "GO111MODULE": "on",
        "GOAMD64": "v1",
        "GOARCH": "amd64",
        "GOBIN": "",
        "GOCACHE": "C:\\Users\\qingshuic\\AppData\\Local\\go-build",
        "GOENV": "C:\\Users\\qingshuic\\AppData\\Roaming\\go\\env",
        "GOEXE": ".exe",
        "GOEXPERIMENT": "",
        "GOFLAGS": "",
        "GOGCCFLAGS": "-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:
\\tmp\\go-build3856010262=/tmp/go-build -gno-record-gcc-switches",
        "GOHOSTARCH": "amd64",
        "GOHOSTOS": "windows",
        "GOINSECURE": "",
        "GOMOD": "C:\\Program Files\\Go\\src\\go.mod",
        "GOMODCACHE": "C:\\Users\\qingshuic\\go\\pkg\\mod",
        "GONOPROXY": "",
        "GONOSUMDB": "",
        "GOOS": "windows",
        "GOPATH": "C:\\Users\\qingshuic\\go",
        "GOPRIVATE": "",
        "GOPROXY": "https://goproxy.cn,direct",
        "GOROOT": "C:\\Program Files\\Go",
        "GOSUMDB": "sum.golang.org",
        "GOTMPDIR": "",
        "GOTOOLDIR": "C:\\Program Files\\Go\\pkg\\tool\\windows_amd64",
        "GOVCS": "",
        "GOVERSION": "go1.18.1",
        "GOWORK": "",
        "PKG_CONFIG": "pkg-config"
}