Scott Baker | 1fe7273 | 2019-10-21 10:58:51 -0700 | [diff] [blame] | 1 | package flags |
| 2 | |
| 3 | import ( |
| 4 | "bufio" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "os" |
| 8 | "reflect" |
| 9 | "sort" |
| 10 | "strconv" |
| 11 | "strings" |
| 12 | ) |
| 13 | |
| 14 | // IniError contains location information on where an error occurred. |
| 15 | type IniError struct { |
| 16 | // The error message. |
| 17 | Message string |
| 18 | |
| 19 | // The filename of the file in which the error occurred. |
| 20 | File string |
| 21 | |
| 22 | // The line number at which the error occurred. |
| 23 | LineNumber uint |
| 24 | } |
| 25 | |
| 26 | // Error provides a "file:line: message" formatted message of the ini error. |
| 27 | func (x *IniError) Error() string { |
| 28 | return fmt.Sprintf( |
| 29 | "%s:%d: %s", |
| 30 | x.File, |
| 31 | x.LineNumber, |
| 32 | x.Message, |
| 33 | ) |
| 34 | } |
| 35 | |
| 36 | // IniOptions for writing |
| 37 | type IniOptions uint |
| 38 | |
| 39 | const ( |
| 40 | // IniNone indicates no options. |
| 41 | IniNone IniOptions = 0 |
| 42 | |
| 43 | // IniIncludeDefaults indicates that default values should be written. |
| 44 | IniIncludeDefaults = 1 << iota |
| 45 | |
| 46 | // IniCommentDefaults indicates that if IniIncludeDefaults is used |
| 47 | // options with default values are written but commented out. |
| 48 | IniCommentDefaults |
| 49 | |
| 50 | // IniIncludeComments indicates that comments containing the description |
| 51 | // of an option should be written. |
| 52 | IniIncludeComments |
| 53 | |
| 54 | // IniDefault provides a default set of options. |
| 55 | IniDefault = IniIncludeComments |
| 56 | ) |
| 57 | |
| 58 | // IniParser is a utility to read and write flags options from and to ini |
| 59 | // formatted strings. |
| 60 | type IniParser struct { |
| 61 | ParseAsDefaults bool // override default flags |
| 62 | |
| 63 | parser *Parser |
| 64 | } |
| 65 | |
| 66 | type iniValue struct { |
| 67 | Name string |
| 68 | Value string |
| 69 | Quoted bool |
| 70 | LineNumber uint |
| 71 | } |
| 72 | |
| 73 | type iniSection []iniValue |
| 74 | |
| 75 | type ini struct { |
| 76 | File string |
| 77 | Sections map[string]iniSection |
| 78 | } |
| 79 | |
| 80 | // NewIniParser creates a new ini parser for a given Parser. |
| 81 | func NewIniParser(p *Parser) *IniParser { |
| 82 | return &IniParser{ |
| 83 | parser: p, |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | // IniParse is a convenience function to parse command line options with default |
| 88 | // settings from an ini formatted file. The provided data is a pointer to a struct |
| 89 | // representing the default option group (named "Application Options"). For |
| 90 | // more control, use flags.NewParser. |
| 91 | func IniParse(filename string, data interface{}) error { |
| 92 | p := NewParser(data, Default) |
| 93 | |
| 94 | return NewIniParser(p).ParseFile(filename) |
| 95 | } |
| 96 | |
| 97 | // ParseFile parses flags from an ini formatted file. See Parse for more |
| 98 | // information on the ini file format. The returned errors can be of the type |
| 99 | // flags.Error or flags.IniError. |
| 100 | func (i *IniParser) ParseFile(filename string) error { |
| 101 | ini, err := readIniFromFile(filename) |
| 102 | |
| 103 | if err != nil { |
| 104 | return err |
| 105 | } |
| 106 | |
| 107 | return i.parse(ini) |
| 108 | } |
| 109 | |
| 110 | // Parse parses flags from an ini format. You can use ParseFile as a |
| 111 | // convenience function to parse from a filename instead of a general |
| 112 | // io.Reader. |
| 113 | // |
| 114 | // The format of the ini file is as follows: |
| 115 | // |
| 116 | // [Option group name] |
| 117 | // option = value |
| 118 | // |
| 119 | // Each section in the ini file represents an option group or command in the |
| 120 | // flags parser. The default flags parser option group (i.e. when using |
| 121 | // flags.Parse) is named 'Application Options'. The ini option name is matched |
| 122 | // in the following order: |
| 123 | // |
| 124 | // 1. Compared to the ini-name tag on the option struct field (if present) |
| 125 | // 2. Compared to the struct field name |
| 126 | // 3. Compared to the option long name (if present) |
| 127 | // 4. Compared to the option short name (if present) |
| 128 | // |
| 129 | // Sections for nested groups and commands can be addressed using a dot `.' |
| 130 | // namespacing notation (i.e [subcommand.Options]). Group section names are |
| 131 | // matched case insensitive. |
| 132 | // |
| 133 | // The returned errors can be of the type flags.Error or flags.IniError. |
| 134 | func (i *IniParser) Parse(reader io.Reader) error { |
| 135 | ini, err := readIni(reader, "") |
| 136 | |
| 137 | if err != nil { |
| 138 | return err |
| 139 | } |
| 140 | |
| 141 | return i.parse(ini) |
| 142 | } |
| 143 | |
| 144 | // WriteFile writes the flags as ini format into a file. See Write |
| 145 | // for more information. The returned error occurs when the specified file |
| 146 | // could not be opened for writing. |
| 147 | func (i *IniParser) WriteFile(filename string, options IniOptions) error { |
| 148 | return writeIniToFile(i, filename, options) |
| 149 | } |
| 150 | |
| 151 | // Write writes the current values of all the flags to an ini format. |
| 152 | // See Parse for more information on the ini file format. You typically |
| 153 | // call this only after settings have been parsed since the default values of each |
| 154 | // option are stored just before parsing the flags (this is only relevant when |
| 155 | // IniIncludeDefaults is _not_ set in options). |
| 156 | func (i *IniParser) Write(writer io.Writer, options IniOptions) { |
| 157 | writeIni(i, writer, options) |
| 158 | } |
| 159 | |
| 160 | func readFullLine(reader *bufio.Reader) (string, error) { |
| 161 | var line []byte |
| 162 | |
| 163 | for { |
| 164 | l, more, err := reader.ReadLine() |
| 165 | |
| 166 | if err != nil { |
| 167 | return "", err |
| 168 | } |
| 169 | |
| 170 | if line == nil && !more { |
| 171 | return string(l), nil |
| 172 | } |
| 173 | |
| 174 | line = append(line, l...) |
| 175 | |
| 176 | if !more { |
| 177 | break |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | return string(line), nil |
| 182 | } |
| 183 | |
| 184 | func optionIniName(option *Option) string { |
| 185 | name := option.tag.Get("_read-ini-name") |
| 186 | |
| 187 | if len(name) != 0 { |
| 188 | return name |
| 189 | } |
| 190 | |
| 191 | name = option.tag.Get("ini-name") |
| 192 | |
| 193 | if len(name) != 0 { |
| 194 | return name |
| 195 | } |
| 196 | |
| 197 | return option.field.Name |
| 198 | } |
| 199 | |
| 200 | func writeGroupIni(cmd *Command, group *Group, namespace string, writer io.Writer, options IniOptions) { |
| 201 | var sname string |
| 202 | |
| 203 | if len(namespace) != 0 { |
| 204 | sname = namespace |
| 205 | } |
| 206 | |
| 207 | if cmd.Group != group && len(group.ShortDescription) != 0 { |
| 208 | if len(sname) != 0 { |
| 209 | sname += "." |
| 210 | } |
| 211 | |
| 212 | sname += group.ShortDescription |
| 213 | } |
| 214 | |
| 215 | sectionwritten := false |
| 216 | comments := (options & IniIncludeComments) != IniNone |
| 217 | |
| 218 | for _, option := range group.options { |
| 219 | if option.isFunc() || option.Hidden { |
| 220 | continue |
| 221 | } |
| 222 | |
| 223 | if len(option.tag.Get("no-ini")) != 0 { |
| 224 | continue |
| 225 | } |
| 226 | |
| 227 | val := option.value |
| 228 | |
| 229 | if (options&IniIncludeDefaults) == IniNone && option.valueIsDefault() { |
| 230 | continue |
| 231 | } |
| 232 | |
| 233 | if !sectionwritten { |
| 234 | fmt.Fprintf(writer, "[%s]\n", sname) |
| 235 | sectionwritten = true |
| 236 | } |
| 237 | |
| 238 | if comments && len(option.Description) != 0 { |
| 239 | fmt.Fprintf(writer, "; %s\n", option.Description) |
| 240 | } |
| 241 | |
| 242 | oname := optionIniName(option) |
| 243 | |
| 244 | commentOption := (options&(IniIncludeDefaults|IniCommentDefaults)) == IniIncludeDefaults|IniCommentDefaults && option.valueIsDefault() |
| 245 | |
| 246 | kind := val.Type().Kind() |
| 247 | switch kind { |
| 248 | case reflect.Slice: |
| 249 | kind = val.Type().Elem().Kind() |
| 250 | |
| 251 | if val.Len() == 0 { |
| 252 | writeOption(writer, oname, kind, "", "", true, option.iniQuote) |
| 253 | } else { |
| 254 | for idx := 0; idx < val.Len(); idx++ { |
| 255 | v, _ := convertToString(val.Index(idx), option.tag) |
| 256 | |
| 257 | writeOption(writer, oname, kind, "", v, commentOption, option.iniQuote) |
| 258 | } |
| 259 | } |
| 260 | case reflect.Map: |
| 261 | kind = val.Type().Elem().Kind() |
| 262 | |
| 263 | if val.Len() == 0 { |
| 264 | writeOption(writer, oname, kind, "", "", true, option.iniQuote) |
| 265 | } else { |
| 266 | mkeys := val.MapKeys() |
| 267 | keys := make([]string, len(val.MapKeys())) |
| 268 | kkmap := make(map[string]reflect.Value) |
| 269 | |
| 270 | for i, k := range mkeys { |
| 271 | keys[i], _ = convertToString(k, option.tag) |
| 272 | kkmap[keys[i]] = k |
| 273 | } |
| 274 | |
| 275 | sort.Strings(keys) |
| 276 | |
| 277 | for _, k := range keys { |
| 278 | v, _ := convertToString(val.MapIndex(kkmap[k]), option.tag) |
| 279 | |
| 280 | writeOption(writer, oname, kind, k, v, commentOption, option.iniQuote) |
| 281 | } |
| 282 | } |
| 283 | default: |
| 284 | v, _ := convertToString(val, option.tag) |
| 285 | |
| 286 | writeOption(writer, oname, kind, "", v, commentOption, option.iniQuote) |
| 287 | } |
| 288 | |
| 289 | if comments { |
| 290 | fmt.Fprintln(writer) |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | if sectionwritten && !comments { |
| 295 | fmt.Fprintln(writer) |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | func writeOption(writer io.Writer, optionName string, optionType reflect.Kind, optionKey string, optionValue string, commentOption bool, forceQuote bool) { |
| 300 | if forceQuote || (optionType == reflect.String && !isPrint(optionValue)) { |
| 301 | optionValue = strconv.Quote(optionValue) |
| 302 | } |
| 303 | |
| 304 | comment := "" |
| 305 | if commentOption { |
| 306 | comment = "; " |
| 307 | } |
| 308 | |
| 309 | fmt.Fprintf(writer, "%s%s =", comment, optionName) |
| 310 | |
| 311 | if optionKey != "" { |
| 312 | fmt.Fprintf(writer, " %s:%s", optionKey, optionValue) |
| 313 | } else if optionValue != "" { |
| 314 | fmt.Fprintf(writer, " %s", optionValue) |
| 315 | } |
| 316 | |
| 317 | fmt.Fprintln(writer) |
| 318 | } |
| 319 | |
| 320 | func writeCommandIni(command *Command, namespace string, writer io.Writer, options IniOptions) { |
| 321 | command.eachGroup(func(group *Group) { |
| 322 | if !group.Hidden { |
| 323 | writeGroupIni(command, group, namespace, writer, options) |
| 324 | } |
| 325 | }) |
| 326 | |
| 327 | for _, c := range command.commands { |
| 328 | var nns string |
| 329 | |
| 330 | if c.Hidden { |
| 331 | continue |
| 332 | } |
| 333 | |
| 334 | if len(namespace) != 0 { |
| 335 | nns = c.Name + "." + nns |
| 336 | } else { |
| 337 | nns = c.Name |
| 338 | } |
| 339 | |
| 340 | writeCommandIni(c, nns, writer, options) |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | func writeIni(parser *IniParser, writer io.Writer, options IniOptions) { |
| 345 | writeCommandIni(parser.parser.Command, "", writer, options) |
| 346 | } |
| 347 | |
| 348 | func writeIniToFile(parser *IniParser, filename string, options IniOptions) error { |
| 349 | file, err := os.Create(filename) |
| 350 | |
| 351 | if err != nil { |
| 352 | return err |
| 353 | } |
| 354 | |
| 355 | defer file.Close() |
| 356 | |
| 357 | writeIni(parser, file, options) |
| 358 | |
| 359 | return nil |
| 360 | } |
| 361 | |
| 362 | func readIniFromFile(filename string) (*ini, error) { |
| 363 | file, err := os.Open(filename) |
| 364 | |
| 365 | if err != nil { |
| 366 | return nil, err |
| 367 | } |
| 368 | |
| 369 | defer file.Close() |
| 370 | |
| 371 | return readIni(file, filename) |
| 372 | } |
| 373 | |
| 374 | func readIni(contents io.Reader, filename string) (*ini, error) { |
| 375 | ret := &ini{ |
| 376 | File: filename, |
| 377 | Sections: make(map[string]iniSection), |
| 378 | } |
| 379 | |
| 380 | reader := bufio.NewReader(contents) |
| 381 | |
| 382 | // Empty global section |
| 383 | section := make(iniSection, 0, 10) |
| 384 | sectionname := "" |
| 385 | |
| 386 | ret.Sections[sectionname] = section |
| 387 | |
| 388 | var lineno uint |
| 389 | |
| 390 | for { |
| 391 | line, err := readFullLine(reader) |
| 392 | |
| 393 | if err == io.EOF { |
| 394 | break |
| 395 | } else if err != nil { |
| 396 | return nil, err |
| 397 | } |
| 398 | |
| 399 | lineno++ |
| 400 | line = strings.TrimSpace(line) |
| 401 | |
| 402 | // Skip empty lines and lines starting with ; (comments) |
| 403 | if len(line) == 0 || line[0] == ';' || line[0] == '#' { |
| 404 | continue |
| 405 | } |
| 406 | |
| 407 | if line[0] == '[' { |
| 408 | if line[0] != '[' || line[len(line)-1] != ']' { |
| 409 | return nil, &IniError{ |
| 410 | Message: "malformed section header", |
| 411 | File: filename, |
| 412 | LineNumber: lineno, |
| 413 | } |
| 414 | } |
| 415 | |
| 416 | name := strings.TrimSpace(line[1 : len(line)-1]) |
| 417 | |
| 418 | if len(name) == 0 { |
| 419 | return nil, &IniError{ |
| 420 | Message: "empty section name", |
| 421 | File: filename, |
| 422 | LineNumber: lineno, |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | sectionname = name |
| 427 | section = ret.Sections[name] |
| 428 | |
| 429 | if section == nil { |
| 430 | section = make(iniSection, 0, 10) |
| 431 | ret.Sections[name] = section |
| 432 | } |
| 433 | |
| 434 | continue |
| 435 | } |
| 436 | |
| 437 | // Parse option here |
| 438 | keyval := strings.SplitN(line, "=", 2) |
| 439 | |
| 440 | if len(keyval) != 2 { |
| 441 | return nil, &IniError{ |
| 442 | Message: fmt.Sprintf("malformed key=value (%s)", line), |
| 443 | File: filename, |
| 444 | LineNumber: lineno, |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | name := strings.TrimSpace(keyval[0]) |
| 449 | value := strings.TrimSpace(keyval[1]) |
| 450 | quoted := false |
| 451 | |
| 452 | if len(value) != 0 && value[0] == '"' { |
| 453 | if v, err := strconv.Unquote(value); err == nil { |
| 454 | value = v |
| 455 | |
| 456 | quoted = true |
| 457 | } else { |
| 458 | return nil, &IniError{ |
| 459 | Message: err.Error(), |
| 460 | File: filename, |
| 461 | LineNumber: lineno, |
| 462 | } |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | section = append(section, iniValue{ |
| 467 | Name: name, |
| 468 | Value: value, |
| 469 | Quoted: quoted, |
| 470 | LineNumber: lineno, |
| 471 | }) |
| 472 | |
| 473 | ret.Sections[sectionname] = section |
| 474 | } |
| 475 | |
| 476 | return ret, nil |
| 477 | } |
| 478 | |
| 479 | func (i *IniParser) matchingGroups(name string) []*Group { |
| 480 | if len(name) == 0 { |
| 481 | var ret []*Group |
| 482 | |
| 483 | i.parser.eachGroup(func(g *Group) { |
| 484 | ret = append(ret, g) |
| 485 | }) |
| 486 | |
| 487 | return ret |
| 488 | } |
| 489 | |
| 490 | g := i.parser.groupByName(name) |
| 491 | |
| 492 | if g != nil { |
| 493 | return []*Group{g} |
| 494 | } |
| 495 | |
| 496 | return nil |
| 497 | } |
| 498 | |
| 499 | func (i *IniParser) parse(ini *ini) error { |
| 500 | p := i.parser |
| 501 | |
| 502 | var quotesLookup = make(map[*Option]bool) |
| 503 | |
| 504 | for name, section := range ini.Sections { |
| 505 | groups := i.matchingGroups(name) |
| 506 | |
| 507 | if len(groups) == 0 { |
| 508 | return newErrorf(ErrUnknownGroup, "could not find option group `%s'", name) |
| 509 | } |
| 510 | |
| 511 | for _, inival := range section { |
| 512 | var opt *Option |
| 513 | |
| 514 | for _, group := range groups { |
| 515 | opt = group.optionByName(inival.Name, func(o *Option, n string) bool { |
| 516 | return strings.ToLower(o.tag.Get("ini-name")) == strings.ToLower(n) |
| 517 | }) |
| 518 | |
| 519 | if opt != nil && len(opt.tag.Get("no-ini")) != 0 { |
| 520 | opt = nil |
| 521 | } |
| 522 | |
| 523 | if opt != nil { |
| 524 | break |
| 525 | } |
| 526 | } |
| 527 | |
| 528 | if opt == nil { |
| 529 | if (p.Options & IgnoreUnknown) == None { |
| 530 | return &IniError{ |
| 531 | Message: fmt.Sprintf("unknown option: %s", inival.Name), |
| 532 | File: ini.File, |
| 533 | LineNumber: inival.LineNumber, |
| 534 | } |
| 535 | } |
| 536 | |
| 537 | continue |
| 538 | } |
| 539 | |
| 540 | // ini value is ignored if override is set and |
| 541 | // value was previously set from non default |
| 542 | if i.ParseAsDefaults && !opt.isSetDefault { |
| 543 | continue |
| 544 | } |
| 545 | |
| 546 | pval := &inival.Value |
| 547 | |
| 548 | if !opt.canArgument() && len(inival.Value) == 0 { |
| 549 | pval = nil |
| 550 | } else { |
| 551 | if opt.value.Type().Kind() == reflect.Map { |
| 552 | parts := strings.SplitN(inival.Value, ":", 2) |
| 553 | |
| 554 | // only handle unquoting |
| 555 | if len(parts) == 2 && parts[1][0] == '"' { |
| 556 | if v, err := strconv.Unquote(parts[1]); err == nil { |
| 557 | parts[1] = v |
| 558 | |
| 559 | inival.Quoted = true |
| 560 | } else { |
| 561 | return &IniError{ |
| 562 | Message: err.Error(), |
| 563 | File: ini.File, |
| 564 | LineNumber: inival.LineNumber, |
| 565 | } |
| 566 | } |
| 567 | |
| 568 | s := parts[0] + ":" + parts[1] |
| 569 | |
| 570 | pval = &s |
| 571 | } |
| 572 | } |
| 573 | } |
| 574 | |
| 575 | if err := opt.set(pval); err != nil { |
| 576 | return &IniError{ |
| 577 | Message: err.Error(), |
| 578 | File: ini.File, |
| 579 | LineNumber: inival.LineNumber, |
| 580 | } |
| 581 | } |
| 582 | |
| 583 | // either all INI values are quoted or only values who need quoting |
| 584 | if _, ok := quotesLookup[opt]; !inival.Quoted || !ok { |
| 585 | quotesLookup[opt] = inival.Quoted |
| 586 | } |
| 587 | |
| 588 | opt.tag.Set("_read-ini-name", inival.Name) |
| 589 | } |
| 590 | } |
| 591 | |
| 592 | for opt, quoted := range quotesLookup { |
| 593 | opt.iniQuote = quoted |
| 594 | } |
| 595 | |
| 596 | return nil |
| 597 | } |