Scott Baker | bdb962b | 2020-04-03 10:53:36 -0700 | [diff] [blame] | 1 | // Copyright 2012 Jesse van den Kieboom. 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 flags |
| 6 | |
| 7 | import ( |
| 8 | "bufio" |
| 9 | "bytes" |
| 10 | "fmt" |
| 11 | "io" |
| 12 | "runtime" |
| 13 | "strings" |
| 14 | "unicode/utf8" |
| 15 | ) |
| 16 | |
| 17 | type alignmentInfo struct { |
| 18 | maxLongLen int |
| 19 | hasShort bool |
| 20 | hasValueName bool |
| 21 | terminalColumns int |
| 22 | indent bool |
| 23 | } |
| 24 | |
| 25 | const ( |
| 26 | paddingBeforeOption = 2 |
| 27 | distanceBetweenOptionAndDescription = 2 |
| 28 | ) |
| 29 | |
| 30 | func (a *alignmentInfo) descriptionStart() int { |
| 31 | ret := a.maxLongLen + distanceBetweenOptionAndDescription |
| 32 | |
| 33 | if a.hasShort { |
| 34 | ret += 2 |
| 35 | } |
| 36 | |
| 37 | if a.maxLongLen > 0 { |
| 38 | ret += 4 |
| 39 | } |
| 40 | |
| 41 | if a.hasValueName { |
| 42 | ret += 3 |
| 43 | } |
| 44 | |
| 45 | return ret |
| 46 | } |
| 47 | |
| 48 | func (a *alignmentInfo) updateLen(name string, indent bool) { |
| 49 | l := utf8.RuneCountInString(name) |
| 50 | |
| 51 | if indent { |
| 52 | l = l + 4 |
| 53 | } |
| 54 | |
| 55 | if l > a.maxLongLen { |
| 56 | a.maxLongLen = l |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | func (p *Parser) getAlignmentInfo() alignmentInfo { |
| 61 | ret := alignmentInfo{ |
| 62 | maxLongLen: 0, |
| 63 | hasShort: false, |
| 64 | hasValueName: false, |
| 65 | terminalColumns: getTerminalColumns(), |
| 66 | } |
| 67 | |
| 68 | if ret.terminalColumns <= 0 { |
| 69 | ret.terminalColumns = 80 |
| 70 | } |
| 71 | |
| 72 | var prevcmd *Command |
| 73 | |
| 74 | p.eachActiveGroup(func(c *Command, grp *Group) { |
| 75 | if c != prevcmd { |
| 76 | for _, arg := range c.args { |
| 77 | ret.updateLen(arg.Name, c != p.Command) |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | for _, info := range grp.options { |
| 82 | if !info.canCli() { |
| 83 | continue |
| 84 | } |
| 85 | |
| 86 | if info.ShortName != 0 { |
| 87 | ret.hasShort = true |
| 88 | } |
| 89 | |
| 90 | if len(info.ValueName) > 0 { |
| 91 | ret.hasValueName = true |
| 92 | } |
| 93 | |
| 94 | l := info.LongNameWithNamespace() + info.ValueName |
| 95 | |
| 96 | if len(info.Choices) != 0 { |
| 97 | l += "[" + strings.Join(info.Choices, "|") + "]" |
| 98 | } |
| 99 | |
| 100 | ret.updateLen(l, c != p.Command) |
| 101 | } |
| 102 | }) |
| 103 | |
| 104 | return ret |
| 105 | } |
| 106 | |
| 107 | func wrapText(s string, l int, prefix string) string { |
| 108 | var ret string |
| 109 | |
| 110 | if l < 10 { |
| 111 | l = 10 |
| 112 | } |
| 113 | |
| 114 | // Basic text wrapping of s at spaces to fit in l |
| 115 | lines := strings.Split(s, "\n") |
| 116 | |
| 117 | for _, line := range lines { |
| 118 | var retline string |
| 119 | |
| 120 | line = strings.TrimSpace(line) |
| 121 | |
| 122 | for len(line) > l { |
| 123 | // Try to split on space |
| 124 | suffix := "" |
| 125 | |
| 126 | pos := strings.LastIndex(line[:l], " ") |
| 127 | |
| 128 | if pos < 0 { |
| 129 | pos = l - 1 |
| 130 | suffix = "-\n" |
| 131 | } |
| 132 | |
| 133 | if len(retline) != 0 { |
| 134 | retline += "\n" + prefix |
| 135 | } |
| 136 | |
| 137 | retline += strings.TrimSpace(line[:pos]) + suffix |
| 138 | line = strings.TrimSpace(line[pos:]) |
| 139 | } |
| 140 | |
| 141 | if len(line) > 0 { |
| 142 | if len(retline) != 0 { |
| 143 | retline += "\n" + prefix |
| 144 | } |
| 145 | |
| 146 | retline += line |
| 147 | } |
| 148 | |
| 149 | if len(ret) > 0 { |
| 150 | ret += "\n" |
| 151 | |
| 152 | if len(retline) > 0 { |
| 153 | ret += prefix |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | ret += retline |
| 158 | } |
| 159 | |
| 160 | return ret |
| 161 | } |
| 162 | |
| 163 | func (p *Parser) writeHelpOption(writer *bufio.Writer, option *Option, info alignmentInfo) { |
| 164 | line := &bytes.Buffer{} |
| 165 | |
| 166 | prefix := paddingBeforeOption |
| 167 | |
| 168 | if info.indent { |
| 169 | prefix += 4 |
| 170 | } |
| 171 | |
| 172 | if option.Hidden { |
| 173 | return |
| 174 | } |
| 175 | |
| 176 | line.WriteString(strings.Repeat(" ", prefix)) |
| 177 | |
| 178 | if option.ShortName != 0 { |
| 179 | line.WriteRune(defaultShortOptDelimiter) |
| 180 | line.WriteRune(option.ShortName) |
| 181 | } else if info.hasShort { |
| 182 | line.WriteString(" ") |
| 183 | } |
| 184 | |
| 185 | descstart := info.descriptionStart() + paddingBeforeOption |
| 186 | |
| 187 | if len(option.LongName) > 0 { |
| 188 | if option.ShortName != 0 { |
| 189 | line.WriteString(", ") |
| 190 | } else if info.hasShort { |
| 191 | line.WriteString(" ") |
| 192 | } |
| 193 | |
| 194 | line.WriteString(defaultLongOptDelimiter) |
| 195 | line.WriteString(option.LongNameWithNamespace()) |
| 196 | } |
| 197 | |
| 198 | if option.canArgument() { |
| 199 | line.WriteRune(defaultNameArgDelimiter) |
| 200 | |
| 201 | if len(option.ValueName) > 0 { |
| 202 | line.WriteString(option.ValueName) |
| 203 | } |
| 204 | |
| 205 | if len(option.Choices) > 0 { |
| 206 | line.WriteString("[" + strings.Join(option.Choices, "|") + "]") |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | written := line.Len() |
| 211 | line.WriteTo(writer) |
| 212 | |
| 213 | if option.Description != "" { |
| 214 | dw := descstart - written |
| 215 | writer.WriteString(strings.Repeat(" ", dw)) |
| 216 | |
| 217 | var def string |
| 218 | |
| 219 | if len(option.DefaultMask) != 0 { |
| 220 | if option.DefaultMask != "-" { |
| 221 | def = option.DefaultMask |
| 222 | } |
| 223 | } else { |
| 224 | def = option.defaultLiteral |
| 225 | } |
| 226 | |
| 227 | var envDef string |
| 228 | if option.EnvDefaultKey != "" { |
| 229 | var envPrintable string |
| 230 | if runtime.GOOS == "windows" { |
| 231 | envPrintable = "%" + option.EnvDefaultKey + "%" |
| 232 | } else { |
| 233 | envPrintable = "$" + option.EnvDefaultKey |
| 234 | } |
| 235 | envDef = fmt.Sprintf(" [%s]", envPrintable) |
| 236 | } |
| 237 | |
| 238 | var desc string |
| 239 | |
| 240 | if def != "" { |
| 241 | desc = fmt.Sprintf("%s (default: %v)%s", option.Description, def, envDef) |
| 242 | } else { |
| 243 | desc = option.Description + envDef |
| 244 | } |
| 245 | |
| 246 | writer.WriteString(wrapText(desc, |
| 247 | info.terminalColumns-descstart, |
| 248 | strings.Repeat(" ", descstart))) |
| 249 | } |
| 250 | |
| 251 | writer.WriteString("\n") |
| 252 | } |
| 253 | |
| 254 | func maxCommandLength(s []*Command) int { |
| 255 | if len(s) == 0 { |
| 256 | return 0 |
| 257 | } |
| 258 | |
| 259 | ret := len(s[0].Name) |
| 260 | |
| 261 | for _, v := range s[1:] { |
| 262 | l := len(v.Name) |
| 263 | |
| 264 | if l > ret { |
| 265 | ret = l |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | return ret |
| 270 | } |
| 271 | |
| 272 | // WriteHelp writes a help message containing all the possible options and |
| 273 | // their descriptions to the provided writer. Note that the HelpFlag parser |
| 274 | // option provides a convenient way to add a -h/--help option group to the |
| 275 | // command line parser which will automatically show the help messages using |
| 276 | // this method. |
| 277 | func (p *Parser) WriteHelp(writer io.Writer) { |
| 278 | if writer == nil { |
| 279 | return |
| 280 | } |
| 281 | |
| 282 | wr := bufio.NewWriter(writer) |
| 283 | aligninfo := p.getAlignmentInfo() |
| 284 | |
| 285 | cmd := p.Command |
| 286 | |
| 287 | for cmd.Active != nil { |
| 288 | cmd = cmd.Active |
| 289 | } |
| 290 | |
| 291 | if p.Name != "" { |
| 292 | wr.WriteString("Usage:\n") |
| 293 | wr.WriteString(" ") |
| 294 | |
| 295 | allcmd := p.Command |
| 296 | |
| 297 | for allcmd != nil { |
| 298 | var usage string |
| 299 | |
| 300 | if allcmd == p.Command { |
| 301 | if len(p.Usage) != 0 { |
| 302 | usage = p.Usage |
| 303 | } else if p.Options&HelpFlag != 0 { |
| 304 | usage = "[OPTIONS]" |
| 305 | } |
| 306 | } else if us, ok := allcmd.data.(Usage); ok { |
| 307 | usage = us.Usage() |
| 308 | } else if allcmd.hasCliOptions() { |
| 309 | usage = fmt.Sprintf("[%s-OPTIONS]", allcmd.Name) |
| 310 | } |
| 311 | |
| 312 | if len(usage) != 0 { |
| 313 | fmt.Fprintf(wr, " %s %s", allcmd.Name, usage) |
| 314 | } else { |
| 315 | fmt.Fprintf(wr, " %s", allcmd.Name) |
| 316 | } |
| 317 | |
| 318 | if len(allcmd.args) > 0 { |
| 319 | fmt.Fprintf(wr, " ") |
| 320 | } |
| 321 | |
| 322 | for i, arg := range allcmd.args { |
| 323 | if i != 0 { |
| 324 | fmt.Fprintf(wr, " ") |
| 325 | } |
| 326 | |
| 327 | name := arg.Name |
| 328 | |
| 329 | if arg.isRemaining() { |
| 330 | name = name + "..." |
| 331 | } |
| 332 | |
| 333 | if !allcmd.ArgsRequired { |
| 334 | fmt.Fprintf(wr, "[%s]", name) |
| 335 | } else { |
| 336 | fmt.Fprintf(wr, "%s", name) |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | if allcmd.Active == nil && len(allcmd.commands) > 0 { |
| 341 | var co, cc string |
| 342 | |
| 343 | if allcmd.SubcommandsOptional { |
| 344 | co, cc = "[", "]" |
| 345 | } else { |
| 346 | co, cc = "<", ">" |
| 347 | } |
| 348 | |
| 349 | visibleCommands := allcmd.visibleCommands() |
| 350 | |
| 351 | if len(visibleCommands) > 3 { |
| 352 | fmt.Fprintf(wr, " %scommand%s", co, cc) |
| 353 | } else { |
| 354 | subcommands := allcmd.sortedVisibleCommands() |
| 355 | names := make([]string, len(subcommands)) |
| 356 | |
| 357 | for i, subc := range subcommands { |
| 358 | names[i] = subc.Name |
| 359 | } |
| 360 | |
| 361 | fmt.Fprintf(wr, " %s%s%s", co, strings.Join(names, " | "), cc) |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | allcmd = allcmd.Active |
| 366 | } |
| 367 | |
| 368 | fmt.Fprintln(wr) |
| 369 | |
| 370 | if len(cmd.LongDescription) != 0 { |
| 371 | fmt.Fprintln(wr) |
| 372 | |
| 373 | t := wrapText(cmd.LongDescription, |
| 374 | aligninfo.terminalColumns, |
| 375 | "") |
| 376 | |
| 377 | fmt.Fprintln(wr, t) |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | c := p.Command |
| 382 | |
| 383 | for c != nil { |
| 384 | printcmd := c != p.Command |
| 385 | |
| 386 | c.eachGroup(func(grp *Group) { |
| 387 | first := true |
| 388 | |
| 389 | // Skip built-in help group for all commands except the top-level |
| 390 | // parser |
| 391 | if grp.Hidden || (grp.isBuiltinHelp && c != p.Command) { |
| 392 | return |
| 393 | } |
| 394 | |
| 395 | for _, info := range grp.options { |
| 396 | if !info.canCli() || info.Hidden { |
| 397 | continue |
| 398 | } |
| 399 | |
| 400 | if printcmd { |
| 401 | fmt.Fprintf(wr, "\n[%s command options]\n", c.Name) |
| 402 | aligninfo.indent = true |
| 403 | printcmd = false |
| 404 | } |
| 405 | |
| 406 | if first && cmd.Group != grp { |
| 407 | fmt.Fprintln(wr) |
| 408 | |
| 409 | if aligninfo.indent { |
| 410 | wr.WriteString(" ") |
| 411 | } |
| 412 | |
| 413 | fmt.Fprintf(wr, "%s:\n", grp.ShortDescription) |
| 414 | first = false |
| 415 | } |
| 416 | |
| 417 | p.writeHelpOption(wr, info, aligninfo) |
| 418 | } |
| 419 | }) |
| 420 | |
| 421 | var args []*Arg |
| 422 | for _, arg := range c.args { |
| 423 | if arg.Description != "" { |
| 424 | args = append(args, arg) |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | if len(args) > 0 { |
| 429 | if c == p.Command { |
| 430 | fmt.Fprintf(wr, "\nArguments:\n") |
| 431 | } else { |
| 432 | fmt.Fprintf(wr, "\n[%s command arguments]\n", c.Name) |
| 433 | } |
| 434 | |
| 435 | descStart := aligninfo.descriptionStart() + paddingBeforeOption |
| 436 | |
| 437 | for _, arg := range args { |
| 438 | argPrefix := strings.Repeat(" ", paddingBeforeOption) |
| 439 | argPrefix += arg.Name |
| 440 | |
| 441 | if len(arg.Description) > 0 { |
| 442 | argPrefix += ":" |
| 443 | wr.WriteString(argPrefix) |
| 444 | |
| 445 | // Space between "arg:" and the description start |
| 446 | descPadding := strings.Repeat(" ", descStart-len(argPrefix)) |
| 447 | // How much space the description gets before wrapping |
| 448 | descWidth := aligninfo.terminalColumns - 1 - descStart |
| 449 | // Whitespace to which we can indent new description lines |
| 450 | descPrefix := strings.Repeat(" ", descStart) |
| 451 | |
| 452 | wr.WriteString(descPadding) |
| 453 | wr.WriteString(wrapText(arg.Description, descWidth, descPrefix)) |
| 454 | } else { |
| 455 | wr.WriteString(argPrefix) |
| 456 | } |
| 457 | |
| 458 | fmt.Fprintln(wr) |
| 459 | } |
| 460 | } |
| 461 | |
| 462 | c = c.Active |
| 463 | } |
| 464 | |
| 465 | scommands := cmd.sortedVisibleCommands() |
| 466 | |
| 467 | if len(scommands) > 0 { |
| 468 | maxnamelen := maxCommandLength(scommands) |
| 469 | |
| 470 | fmt.Fprintln(wr) |
| 471 | fmt.Fprintln(wr, "Available commands:") |
| 472 | |
| 473 | for _, c := range scommands { |
| 474 | fmt.Fprintf(wr, " %s", c.Name) |
| 475 | |
| 476 | if len(c.ShortDescription) > 0 { |
| 477 | pad := strings.Repeat(" ", maxnamelen-len(c.Name)) |
| 478 | fmt.Fprintf(wr, "%s %s", pad, c.ShortDescription) |
| 479 | |
| 480 | if len(c.Aliases) > 0 { |
| 481 | fmt.Fprintf(wr, " (aliases: %s)", strings.Join(c.Aliases, ", ")) |
| 482 | } |
| 483 | |
| 484 | } |
| 485 | |
| 486 | fmt.Fprintln(wr) |
| 487 | } |
| 488 | } |
| 489 | |
| 490 | wr.Flush() |
| 491 | } |