Pull in go-flags, modified to build on Solaris

github.com/jessevdk/go-flags/help.go

@@ -0,0 +1,275 @@
+// Copyright 2012 Jesse van den Kieboom. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package flags
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"unicode/utf8"
+)
+
+type alignmentInfo struct {
+	maxLongLen      int
+	hasShort        bool
+	hasValueName    bool
+	terminalColumns int
+}
+
+func (p *Parser) getAlignmentInfo() alignmentInfo {
+	ret := alignmentInfo{
+		maxLongLen:      0,
+		hasShort:        false,
+		hasValueName:    false,
+		terminalColumns: getTerminalColumns(),
+	}
+
+	if ret.terminalColumns <= 0 {
+		ret.terminalColumns = 80
+	}
+
+	p.eachActiveGroup(func(grp *Group) {
+		for _, info := range grp.options {
+			if info.ShortName != 0 {
+				ret.hasShort = true
+			}
+
+			lv := utf8.RuneCountInString(info.ValueName)
+
+			if lv != 0 {
+				ret.hasValueName = true
+			}
+
+			l := utf8.RuneCountInString(info.LongName) + lv
+
+			if l > ret.maxLongLen {
+				ret.maxLongLen = l
+			}
+		}
+	})
+
+	return ret
+}
+
+func (p *Parser) writeHelpOption(writer *bufio.Writer, option *Option, info alignmentInfo) {
+	line := &bytes.Buffer{}
+
+	distanceBetweenOptionAndDescription := 2
+	paddingBeforeOption := 2
+
+	line.WriteString(strings.Repeat(" ", paddingBeforeOption))
+
+	if option.ShortName != 0 {
+		line.WriteRune(defaultShortOptDelimiter)
+		line.WriteRune(option.ShortName)
+	} else if info.hasShort {
+		line.WriteString("  ")
+	}
+
+	descstart := info.maxLongLen + paddingBeforeOption + distanceBetweenOptionAndDescription
+
+	if info.hasShort {
+		descstart += 2
+	}
+
+	if info.maxLongLen > 0 {
+		descstart += 4
+	}
+
+	if info.hasValueName {
+		descstart += 3
+	}
+
+	if len(option.LongName) > 0 {
+		if option.ShortName != 0 {
+			line.WriteString(", ")
+		} else if info.hasShort {
+			line.WriteString("  ")
+		}
+
+		line.WriteString(defaultLongOptDelimiter)
+		line.WriteString(option.LongName)
+	}
+
+	if option.canArgument() {
+		line.WriteRune(defaultNameArgDelimiter)
+
+		if len(option.ValueName) > 0 {
+			line.WriteString(option.ValueName)
+		}
+	}
+
+	written := line.Len()
+	line.WriteTo(writer)
+
+	if option.Description != "" {
+		dw := descstart - written
+		writer.WriteString(strings.Repeat(" ", dw))
+
+		def := ""
+		defs := option.Default
+
+		if len(option.DefaultMask) != 0 {
+			if option.DefaultMask != "-" {
+				def = option.DefaultMask
+			}
+		} else if len(defs) == 0 && option.canArgument() {
+			var showdef bool
+
+			switch option.field.Type.Kind() {
+			case reflect.Func, reflect.Ptr:
+				showdef = !option.value.IsNil()
+			case reflect.Slice, reflect.String, reflect.Array:
+				showdef = option.value.Len() > 0
+			case reflect.Map:
+				showdef = !option.value.IsNil() && option.value.Len() > 0
+			default:
+				zeroval := reflect.Zero(option.field.Type)
+				showdef = !reflect.DeepEqual(zeroval.Interface(), option.value.Interface())
+			}
+
+			if showdef {
+				def, _ = convertToString(option.value, option.tag)
+			}
+		} else if len(defs) != 0 {
+			def = strings.Join(defs, ", ")
+		}
+
+		var desc string
+
+		if def != "" {
+			desc = fmt.Sprintf("%s (%v)", option.Description, def)
+		} else {
+			desc = option.Description
+		}
+
+		writer.WriteString(wrapText(desc,
+			info.terminalColumns-descstart,
+			strings.Repeat(" ", descstart)))
+	}
+
+	writer.WriteString("\n")
+}
+
+func maxCommandLength(s []*Command) int {
+	if len(s) == 0 {
+		return 0
+	}
+
+	ret := len(s[0].Name)
+
+	for _, v := range s[1:] {
+		l := len(v.Name)
+
+		if l > ret {
+			ret = l
+		}
+	}
+
+	return ret
+}
+
+// WriteHelp writes a help message containing all the possible options and
+// their descriptions to the provided writer. Note that the HelpFlag parser
+// option provides a convenient way to add a -h/--help option group to the
+// command line parser which will automatically show the help messages using
+// this method.
+func (p *Parser) WriteHelp(writer io.Writer) {
+	if writer == nil {
+		return
+	}
+
+	wr := bufio.NewWriter(writer)
+	aligninfo := p.getAlignmentInfo()
+
+	cmd := p.Command
+
+	for cmd.Active != nil {
+		cmd = cmd.Active
+	}
+
+	if p.Name != "" {
+		wr.WriteString("Usage:\n")
+		wr.WriteString(" ")
+
+		allcmd := p.Command
+
+		for allcmd != nil {
+			var usage string
+
+			if allcmd == p.Command {
+				if len(p.Usage) != 0 {
+					usage = p.Usage
+				} else {
+					usage = "[OPTIONS]"
+				}
+			} else if us, ok := allcmd.data.(Usage); ok {
+				usage = us.Usage()
+			} else {
+				usage = fmt.Sprintf("[%s-OPTIONS]", allcmd.Name)
+			}
+
+			if len(usage) != 0 {
+				fmt.Fprintf(wr, " %s %s", allcmd.Name, usage)
+			} else {
+				fmt.Fprintf(wr, " %s", allcmd.Name)
+			}
+
+			allcmd = allcmd.Active
+		}
+
+		fmt.Fprintln(wr)
+
+		if len(cmd.LongDescription) != 0 {
+			fmt.Fprintln(wr)
+
+			t := wrapText(cmd.LongDescription,
+				aligninfo.terminalColumns,
+				"")
+
+			fmt.Fprintln(wr, t)
+		}
+	}
+
+	p.eachActiveGroup(func(grp *Group) {
+		first := true
+
+		for _, info := range grp.options {
+			if info.canCli() {
+				if first {
+					fmt.Fprintf(wr, "\n%s:\n", grp.ShortDescription)
+					first = false
+				}
+
+				p.writeHelpOption(wr, info, aligninfo)
+			}
+		}
+	})
+
+	scommands := cmd.sortedCommands()
+
+	if len(scommands) > 0 {
+		maxnamelen := maxCommandLength(scommands)
+
+		fmt.Fprintln(wr)
+		fmt.Fprintln(wr, "Available commands:")
+
+		for _, c := range scommands {
+			fmt.Fprintf(wr, "  %s", c.Name)
+
+			if len(c.ShortDescription) > 0 {
+				pad := strings.Repeat(" ", maxnamelen-len(c.Name))
+				fmt.Fprintf(wr, "%s  %s", pad, c.ShortDescription)
+			}
+
+			fmt.Fprintln(wr)
+		}
+	}
+
+	wr.Flush()
+}