github.com/vugu/vugu@v0.3.5/distutil/exec.go (about)

     1  package distutil
     2  
     3  import (
     4  	"fmt"
     5  	"os"
     6  	"os/exec"
     7  	"path/filepath"
     8  	"strings"
     9  )
    10  
    11  // Must panics if error.
    12  func Must(err error) {
    13  	if err != nil {
    14  		panic(err)
    15  	}
    16  }
    17  
    18  // MustEnvExec is like MustExec but also sets specific environment variables.
    19  func MustEnvExec(env2 []string, name string, arg ...string) string {
    20  
    21  	env := os.Environ()
    22  
    23  	b, err := exec.Command("go", "env", "GOPATH").CombinedOutput()
    24  	if err != nil {
    25  		panic(err)
    26  	}
    27  	goBinDir := filepath.Join(strings.TrimSpace(string(b)), "bin")
    28  	_, err = os.Stat(goBinDir)
    29  	if err == nil { // if dir exists, let's try adding it to PATH env
    30  		for i := 0; i < len(env); i++ {
    31  			if strings.HasPrefix(env[i], "PATH=") {
    32  				env[i] = fmt.Sprintf("%s%c%s", env[i], os.PathListSeparator, goBinDir)
    33  				goto donePath
    34  			}
    35  		}
    36  		// no path... maybe we shoule add it?  pretty strange environment with no path, not putting anything here for now
    37  	}
    38  donePath:
    39  
    40  	env = append(env, env2...)
    41  
    42  	cmd := exec.Command(name, arg...)
    43  	cmd.Env = env
    44  
    45  	b, err = cmd.CombinedOutput()
    46  	if err != nil {
    47  		err2 := fmt.Errorf("error running: %s %v; err=%v; output:\n%s\n", name, arg, err, b)
    48  		fmt.Print(err2)
    49  		panic(err2)
    50  	}
    51  
    52  	return string(b)
    53  }
    54  
    55  // MustExec wraps exec.Command(...).CombinedOutput() with certain differences.
    56  // If `go env GOPATH`/bin exists it is added to the PATH environment variable.
    57  // Upon error the output of the command and the error will be printed and it will panic.
    58  // Upon success the output is returned as a string.
    59  func MustExec(name string, arg ...string) string {
    60  	return MustEnvExec(nil, name, arg...)
    61  }