goversion

README

goversion

Print the latest released Go version and the one installed locally.

Why

Knowing whether your local toolchain is current is a small but recurring question — when triaging build issues, before opening a PR, or in CI gates. goversion answers it in one line, with no surprises and no dependencies beyond Go itself.

Install

go install github.com/olivere/goversion/cmd/goversion@latest

(Tagged binary releases will follow once the tool stabilises.)

Usage

$ goversion
Latest:    go1.24.2
Installed: go1.23.4

JSON for scripts:

$ goversion -json
{"latest":"go1.24.2","installed":"go1.23.4"}

CI gate — exit 1 if your installed Go is older than upstream:

$ goversion -check && echo "up to date"

When go isn't on PATH, goversion says so plainly rather than guessing:

$ env -i PATH= goversion
note: 'go' not found on PATH
Latest:    go1.24.2
Installed: <not installed>

Other flags:

Flag	Default	Purpose
-timeout DUR	10s	Network timeout for the latest-version lookup
-json	off	Emit {"latest":"…","installed":"…"} on stdout
-check	off	Exit 1 if installed Go is older than latest
-version	—	Print goversion's own version and exit

Exit codes

Code	Meaning
0	Success (and, with -check, installed ≥ latest)
1	-check set and installed Go is older than latest
2	Operational failure (network, missing go, malformed flag, etc.)

Stderr is reserved for diagnostics; stdout carries data only. In -json mode, stdout is JSON only.

How it works

• Latest version comes from https://go.dev/VERSION?m=text — the tooling-friendly endpoint the Go installer scripts hit. The first line of the response is the bare version (e.g. go1.24.2); we validate the format before printing it.
• Installed version comes from invoking go version and parsing its output. We do not fall back to runtime.Version(): that constant reports the toolchain that compiled goversion itself, not whatever Go you have installed today, so substituting it would be a lie. When go isn't on PATH we say so explicitly and exit 2.

Development

goversion/
├── cmd/goversion/      # CLI entrypoint
├── internal/latest/    # go.dev fetcher
├── internal/local/     # `go version` parser
└── internal/semver/    # tiny "goX.Y[.Z][pre]" parser for -check

make test    # go test -race ./...
make lint    # go vet + staticcheck (if installed)
make build   # produces ./bin/goversion
make install # go install ./cmd/goversion

Contributing

Issues and pull requests are welcome at https://github.com/olivere/goversion. Please run make test and make lint before opening a PR.

License

MIT — see LICENSE.