github.com/sbinet/go@v0.0.0-20160827155028-54d7de7dd62b/src/cmd/dist/main.go (about)

     1  // Copyright 2012 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 main
     6  
     7  import (
     8  	"flag"
     9  	"fmt"
    10  	"os"
    11  	"strconv"
    12  )
    13  
    14  // cmdtab records the available commands.
    15  var cmdtab = []struct {
    16  	name string
    17  	f    func()
    18  }{
    19  	{"banner", cmdbanner},
    20  	{"bootstrap", cmdbootstrap},
    21  	{"clean", cmdclean},
    22  	{"env", cmdenv},
    23  	{"install", cmdinstall},
    24  	{"list", cmdlist},
    25  	{"test", cmdtest},
    26  	{"version", cmdversion},
    27  }
    28  
    29  // The OS-specific main calls into the portable code here.
    30  func xmain() {
    31  	if len(os.Args) < 2 {
    32  		usage()
    33  	}
    34  	cmd := os.Args[1]
    35  	os.Args = os.Args[1:] // for flag parsing during cmd
    36  	for _, ct := range cmdtab {
    37  		if ct.name == cmd {
    38  			flag.Usage = func() {
    39  				fmt.Fprintf(os.Stderr, "usage: go tool dist %s [options]\n", cmd)
    40  				flag.PrintDefaults()
    41  				os.Exit(2)
    42  			}
    43  			ct.f()
    44  			return
    45  		}
    46  	}
    47  
    48  	xprintf("unknown command %s\n", cmd)
    49  	usage()
    50  }
    51  
    52  func xflagparse(maxargs int) {
    53  	flag.Var((*count)(&vflag), "v", "verbosity")
    54  	flag.Parse()
    55  	if maxargs >= 0 && flag.NArg() > maxargs {
    56  		flag.Usage()
    57  	}
    58  }
    59  
    60  // count is a flag.Value that is like a flag.Bool and a flag.Int.
    61  // If used as -name, it increments the count, but -name=x sets the count.
    62  // Used for verbose flag -v.
    63  type count int
    64  
    65  func (c *count) String() string {
    66  	return fmt.Sprint(int(*c))
    67  }
    68  
    69  func (c *count) Set(s string) error {
    70  	switch s {
    71  	case "true":
    72  		*c++
    73  	case "false":
    74  		*c = 0
    75  	default:
    76  		n, err := strconv.Atoi(s)
    77  		if err != nil {
    78  			return fmt.Errorf("invalid count %q", s)
    79  		}
    80  		*c = count(n)
    81  	}
    82  	return nil
    83  }
    84  
    85  func (c *count) IsBoolFlag() bool {
    86  	return true
    87  }