github.com/jd-ly/tools@v0.5.7/internal/gocommand/version.go (about) 1 // Copyright 2020 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package gocommand 6 7 import ( 8 "context" 9 "fmt" 10 "strings" 11 ) 12 13 // GoVersion checks the go version by running "go list" with modules off. 14 // It returns the X in Go 1.X. 15 func GoVersion(ctx context.Context, inv Invocation, r *Runner) (int, error) { 16 inv.Verb = "list" 17 inv.Args = []string{"-e", "-f", `{{context.ReleaseTags}}`} 18 inv.Env = append(append([]string{}, inv.Env...), "GO111MODULE=off") 19 // Unset any unneeded flags. 20 inv.ModFile = "" 21 inv.ModFlag = "" 22 stdoutBytes, err := r.Run(ctx, inv) 23 if err != nil { 24 return 0, err 25 } 26 stdout := stdoutBytes.String() 27 if len(stdout) < 3 { 28 return 0, fmt.Errorf("bad ReleaseTags output: %q", stdout) 29 } 30 // Split up "[go1.1 go1.15]" 31 tags := strings.Fields(stdout[1 : len(stdout)-2]) 32 for i := len(tags) - 1; i >= 0; i-- { 33 var version int 34 if _, err := fmt.Sscanf(tags[i], "go1.%d", &version); err != nil { 35 continue 36 } 37 return version, nil 38 } 39 return 0, fmt.Errorf("no parseable ReleaseTags in %v", tags) 40 }