| 1 | package IO::Handle; |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | IO::Handle - supply object methods for I/O handles |
| 6 | |
| 7 | =head1 SYNOPSIS |
| 8 | |
| 9 | use IO::Handle; |
| 10 | |
| 11 | $fh = new IO::Handle; |
| 12 | if ($fh->open "< file") { |
| 13 | print <$fh>; |
| 14 | $fh->close; |
| 15 | } |
| 16 | |
| 17 | $fh = new IO::Handle "> FOO"; |
| 18 | if (defined $fh) { |
| 19 | print $fh "bar\n"; |
| 20 | $fh->close; |
| 21 | } |
| 22 | |
| 23 | $fh = new IO::Handle "file", "r"; |
| 24 | if (defined $fh) { |
| 25 | print <$fh>; |
| 26 | undef $fh; # automatically closes the file |
| 27 | } |
| 28 | |
| 29 | $fh = new IO::Handle "file", O_WRONLY|O_APPEND; |
| 30 | if (defined $fh) { |
| 31 | print $fh "corge\n"; |
| 32 | undef $fh; # automatically closes the file |
| 33 | } |
| 34 | |
| 35 | $pos = $fh->getpos; |
| 36 | $fh->setpos $pos; |
| 37 | |
| 38 | $fh->setvbuf($buffer_var, _IOLBF, 1024); |
| 39 | |
| 40 | autoflush STDOUT 1; |
| 41 | |
| 42 | =head1 DESCRIPTION |
| 43 | |
| 44 | C<IO::Handle> is the base class for all other IO handle classes. |
| 45 | A C<IO::Handle> object is a reference to a symbol (see the C<Symbol> package) |
| 46 | |
| 47 | =head1 CONSTRUCTOR |
| 48 | |
| 49 | =over 4 |
| 50 | |
| 51 | =item new () |
| 52 | |
| 53 | Creates a new C<IO::Handle> object. |
| 54 | |
| 55 | =item new_from_fd ( FD, MODE ) |
| 56 | |
| 57 | Creates a C<IO::Handle> like C<new> does. |
| 58 | It requires two parameters, which are passed to the method C<fdopen>; |
| 59 | if the fdopen fails, the object is destroyed. Otherwise, it is returned |
| 60 | to the caller. |
| 61 | |
| 62 | =back |
| 63 | |
| 64 | =head1 METHODS |
| 65 | |
| 66 | If the C function setvbuf() is available, then C<IO::Handle::setvbuf> |
| 67 | sets the buffering policy for the IO::Handle. The calling sequence |
| 68 | for the Perl function is the same as its C counterpart, including the |
| 69 | macros C<_IOFBF>, C<_IOLBF>, and C<_IONBF>, except that the buffer |
| 70 | parameter specifies a scalar variable to use as a buffer. WARNING: A |
| 71 | variable used as a buffer by C<IO::Handle::setvbuf> must not be |
| 72 | modified in any way until the IO::Handle is closed or until |
| 73 | C<IO::Handle::setvbuf> is called again, or memory corruption may |
| 74 | result! |
| 75 | |
| 76 | See L<perlfunc> for complete descriptions of each of the following |
| 77 | supported C<IO::Handle> methods, which are just front ends for the |
| 78 | corresponding built-in functions: |
| 79 | |
| 80 | close |
| 81 | fileno |
| 82 | getc |
| 83 | gets |
| 84 | eof |
| 85 | read |
| 86 | truncate |
| 87 | stat |
| 88 | print |
| 89 | printf |
| 90 | sysread |
| 91 | syswrite |
| 92 | |
| 93 | See L<perlvar> for complete descriptions of each of the following |
| 94 | supported C<IO::Handle> methods: |
| 95 | |
| 96 | autoflush |
| 97 | output_field_separator |
| 98 | output_record_separator |
| 99 | input_record_separator |
| 100 | input_line_number |
| 101 | format_page_number |
| 102 | format_lines_per_page |
| 103 | format_lines_left |
| 104 | format_name |
| 105 | format_top_name |
| 106 | format_line_break_characters |
| 107 | format_formfeed |
| 108 | format_write |
| 109 | |
| 110 | Furthermore, for doing normal I/O you might need these: |
| 111 | |
| 112 | =over |
| 113 | |
| 114 | =item $fh->getline |
| 115 | |
| 116 | This works like <$fh> described in L<perlop/"I/O Operators"> |
| 117 | except that it's more readable and can be safely called in an |
| 118 | array context but still returns just one line. |
| 119 | |
| 120 | =item $fh->getlines |
| 121 | |
| 122 | This works like <$fh> when called in an array context to |
| 123 | read all the remaining lines in a file, except that it's more readable. |
| 124 | It will also croak() if accidentally called in a scalar context. |
| 125 | |
| 126 | =item $fh->fdopen ( FD, MODE ) |
| 127 | |
| 128 | C<fdopen> is like an ordinary C<open> except that its first parameter |
| 129 | is not a filename but rather a file handle name, a IO::Handle object, |
| 130 | or a file descriptor number. |
| 131 | |
| 132 | =item $fh->write ( BUF, LEN [, OFFSET }\] ) |
| 133 | |
| 134 | C<write> is like C<write> found in C, that is it is the |
| 135 | opposite of read. The wrapper for the perl C<write> function is |
| 136 | called C<format_write>. |
| 137 | |
| 138 | =item $fh->opened |
| 139 | |
| 140 | Returns true if the object is currently a valid file descriptor. |
| 141 | |
| 142 | =back |
| 143 | |
| 144 | Lastly, a special method for working under B<-T> and setuid/gid scripts: |
| 145 | |
| 146 | =over |
| 147 | |
| 148 | =item $fh->untaint |
| 149 | |
| 150 | Marks the object as taint-clean, and as such data read from it will also |
| 151 | be considered taint-clean. Note that this is a very trusting action to |
| 152 | take, and appropriate consideration for the data source and potential |
| 153 | vulnerability should be kept in mind. |
| 154 | |
| 155 | =back |
| 156 | |
| 157 | =head1 NOTE |
| 158 | |
| 159 | A C<IO::Handle> object is a GLOB reference. Some modules that |
| 160 | inherit from C<IO::Handle> may want to keep object related variables |
| 161 | in the hash table part of the GLOB. In an attempt to prevent modules |
| 162 | trampling on each other I propose the that any such module should prefix |
| 163 | its variables with its own name separated by _'s. For example the IO::Socket |
| 164 | module keeps a C<timeout> variable in 'io_socket_timeout'. |
| 165 | |
| 166 | =head1 SEE ALSO |
| 167 | |
| 168 | L<perlfunc>, |
| 169 | L<perlop/"I/O Operators">, |
| 170 | L<FileHandle> |
| 171 | |
| 172 | =head1 BUGS |
| 173 | |
| 174 | Due to backwards compatibility, all filehandles resemble objects |
| 175 | of class C<IO::Handle>, or actually classes derived from that class. |
| 176 | They actually aren't. Which means you can't derive your own |
| 177 | class from C<IO::Handle> and inherit those methods. |
| 178 | |
| 179 | =head1 HISTORY |
| 180 | |
| 181 | Derived from FileHandle.pm by Graham Barr E<lt>F<bodg@tiuk.ti.com>E<gt> |
| 182 | |
| 183 | =cut |
| 184 | |
| 185 | require 5.000; |
| 186 | use strict; |
| 187 | use vars qw($VERSION @EXPORT_OK $AUTOLOAD @ISA); |
| 188 | use Carp; |
| 189 | use Symbol; |
| 190 | use SelectSaver; |
| 191 | |
| 192 | require Exporter; |
| 193 | @ISA = qw(Exporter); |
| 194 | |
| 195 | $VERSION = "1.14"; |
| 196 | |
| 197 | @EXPORT_OK = qw( |
| 198 | autoflush |
| 199 | output_field_separator |
| 200 | output_record_separator |
| 201 | input_record_separator |
| 202 | input_line_number |
| 203 | format_page_number |
| 204 | format_lines_per_page |
| 205 | format_lines_left |
| 206 | format_name |
| 207 | format_top_name |
| 208 | format_line_break_characters |
| 209 | format_formfeed |
| 210 | format_write |
| 211 | |
| 212 | print |
| 213 | printf |
| 214 | getline |
| 215 | getlines |
| 216 | |
| 217 | SEEK_SET |
| 218 | SEEK_CUR |
| 219 | SEEK_END |
| 220 | _IOFBF |
| 221 | _IOLBF |
| 222 | _IONBF |
| 223 | |
| 224 | _open_mode_string |
| 225 | ); |
| 226 | |
| 227 | |
| 228 | ################################################ |
| 229 | ## Interaction with the XS. |
| 230 | ## |
| 231 | |
| 232 | require DynaLoader; |
| 233 | @IO::ISA = qw(DynaLoader); |
| 234 | bootstrap IO $VERSION; |
| 235 | |
| 236 | sub AUTOLOAD { |
| 237 | if ($AUTOLOAD =~ /::(_?[a-z])/) { |
| 238 | $AutoLoader::AUTOLOAD = $AUTOLOAD; |
| 239 | goto &AutoLoader::AUTOLOAD |
| 240 | } |
| 241 | my $constname = $AUTOLOAD; |
| 242 | $constname =~ s/.*:://; |
| 243 | my $val = constant($constname); |
| 244 | defined $val or croak "$constname is not a valid IO::Handle macro"; |
| 245 | no strict 'refs'; |
| 246 | *$AUTOLOAD = sub { $val }; |
| 247 | goto &$AUTOLOAD; |
| 248 | } |
| 249 | |
| 250 | |
| 251 | ################################################ |
| 252 | ## Constructors, destructors. |
| 253 | ## |
| 254 | |
| 255 | sub new { |
| 256 | my $class = ref($_[0]) || $_[0] || "IO::Handle"; |
| 257 | @_ == 1 or croak "usage: new $class"; |
| 258 | my $fh = gensym; |
| 259 | bless $fh, $class; |
| 260 | } |
| 261 | |
| 262 | sub new_from_fd { |
| 263 | my $class = ref($_[0]) || $_[0] || "IO::Handle"; |
| 264 | @_ == 3 or croak "usage: new_from_fd $class FD, MODE"; |
| 265 | my $fh = gensym; |
| 266 | shift; |
| 267 | IO::Handle::fdopen($fh, @_) |
| 268 | or return undef; |
| 269 | bless $fh, $class; |
| 270 | } |
| 271 | |
| 272 | sub DESTROY { |
| 273 | my ($fh) = @_; |
| 274 | |
| 275 | # During global object destruction, this function may be called |
| 276 | # on FILEHANDLEs as well as on the GLOBs that contains them. |
| 277 | # Thus the following trickery. If only the CORE file operators |
| 278 | # could deal with FILEHANDLEs, it wouldn't be necessary... |
| 279 | |
| 280 | if ($fh =~ /=FILEHANDLE\(/) { |
| 281 | local *TMP = $fh; |
| 282 | close(TMP) |
| 283 | if defined fileno(TMP); |
| 284 | } |
| 285 | else { |
| 286 | close($fh) |
| 287 | if defined fileno($fh); |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | ################################################ |
| 292 | ## Open and close. |
| 293 | ## |
| 294 | |
| 295 | sub _open_mode_string { |
| 296 | my ($mode) = @_; |
| 297 | $mode =~ /^\+?(<|>>?)$/ |
| 298 | or $mode =~ s/^r(\+?)$/$1</ |
| 299 | or $mode =~ s/^w(\+?)$/$1>/ |
| 300 | or $mode =~ s/^a(\+?)$/$1>>/ |
| 301 | or croak "IO::Handle: bad open mode: $mode"; |
| 302 | $mode; |
| 303 | } |
| 304 | |
| 305 | sub fdopen { |
| 306 | @_ == 3 or croak 'usage: $fh->fdopen(FD, MODE)'; |
| 307 | my ($fh, $fd, $mode) = @_; |
| 308 | local(*GLOB); |
| 309 | |
| 310 | if (ref($fd) && "".$fd =~ /GLOB\(/o) { |
| 311 | # It's a glob reference; Alias it as we cannot get name of anon GLOBs |
| 312 | my $n = qualify(*GLOB); |
| 313 | *GLOB = *{*$fd}; |
| 314 | $fd = $n; |
| 315 | } elsif ($fd =~ m#^\d+$#) { |
| 316 | # It's an FD number; prefix with "=". |
| 317 | $fd = "=$fd"; |
| 318 | } |
| 319 | |
| 320 | open($fh, _open_mode_string($mode) . '&' . $fd) |
| 321 | ? $fh : undef; |
| 322 | } |
| 323 | |
| 324 | sub close { |
| 325 | @_ == 1 or croak 'usage: $fh->close()'; |
| 326 | my($fh) = @_; |
| 327 | my $r = close($fh); |
| 328 | |
| 329 | # This may seem as though it should be in IO::Pipe, but the |
| 330 | # object gets blessed out of IO::Pipe when reader/writer is called |
| 331 | waitpid(${*$fh}{'io_pipe_pid'},0) |
| 332 | if(defined ${*$fh}{'io_pipe_pid'}); |
| 333 | |
| 334 | $r; |
| 335 | } |
| 336 | |
| 337 | ################################################ |
| 338 | ## Normal I/O functions. |
| 339 | ## |
| 340 | |
| 341 | # flock |
| 342 | # select |
| 343 | |
| 344 | sub opened { |
| 345 | @_ == 1 or croak 'usage: $fh->opened()'; |
| 346 | defined fileno($_[0]); |
| 347 | } |
| 348 | |
| 349 | sub fileno { |
| 350 | @_ == 1 or croak 'usage: $fh->fileno()'; |
| 351 | fileno($_[0]); |
| 352 | } |
| 353 | |
| 354 | sub getc { |
| 355 | @_ == 1 or croak 'usage: $fh->getc()'; |
| 356 | getc($_[0]); |
| 357 | } |
| 358 | |
| 359 | sub gets { |
| 360 | @_ == 1 or croak 'usage: $fh->gets()'; |
| 361 | my ($handle) = @_; |
| 362 | scalar <$handle>; |
| 363 | } |
| 364 | |
| 365 | sub eof { |
| 366 | @_ == 1 or croak 'usage: $fh->eof()'; |
| 367 | eof($_[0]); |
| 368 | } |
| 369 | |
| 370 | sub print { |
| 371 | @_ or croak 'usage: $fh->print([ARGS])'; |
| 372 | my $this = shift; |
| 373 | print $this @_; |
| 374 | } |
| 375 | |
| 376 | sub printf { |
| 377 | @_ >= 2 or croak 'usage: $fh->printf(FMT,[ARGS])'; |
| 378 | my $this = shift; |
| 379 | printf $this @_; |
| 380 | } |
| 381 | |
| 382 | sub getline { |
| 383 | @_ == 1 or croak 'usage: $fh->getline'; |
| 384 | my $this = shift; |
| 385 | return scalar <$this>; |
| 386 | } |
| 387 | |
| 388 | sub getlines { |
| 389 | @_ == 1 or croak 'usage: $fh->getline()'; |
| 390 | wantarray or |
| 391 | croak 'Can\'t call $fh->getlines in a scalar context, use $fh->getline'; |
| 392 | my $this = shift; |
| 393 | return <$this>; |
| 394 | } |
| 395 | |
| 396 | sub truncate { |
| 397 | @_ == 2 or croak 'usage: $fh->truncate(LEN)'; |
| 398 | truncate($_[0], $_[1]); |
| 399 | } |
| 400 | |
| 401 | sub read { |
| 402 | @_ == 3 || @_ == 4 or croak '$fh->read(BUF, LEN [, OFFSET])'; |
| 403 | read($_[0], $_[1], $_[2], $_[3] || 0); |
| 404 | } |
| 405 | |
| 406 | sub sysread { |
| 407 | @_ == 3 || @_ == 4 or croak '$fh->sysread(BUF, LEN [, OFFSET])'; |
| 408 | sysread($_[0], $_[1], $_[2], $_[3] || 0); |
| 409 | } |
| 410 | |
| 411 | sub write { |
| 412 | @_ == 3 || @_ == 4 or croak '$fh->write(BUF, LEN [, OFFSET])'; |
| 413 | local($\) = ""; |
| 414 | print { $_[0] } substr($_[1], $_[3] || 0, $_[2]); |
| 415 | } |
| 416 | |
| 417 | sub syswrite { |
| 418 | @_ == 3 || @_ == 4 or croak '$fh->syswrite(BUF, LEN [, OFFSET])'; |
| 419 | syswrite($_[0], $_[1], $_[2], $_[3] || 0); |
| 420 | } |
| 421 | |
| 422 | sub stat { |
| 423 | @_ == 1 or croak 'usage: $fh->stat()'; |
| 424 | stat($_[0]); |
| 425 | } |
| 426 | |
| 427 | ################################################ |
| 428 | ## State modification functions. |
| 429 | ## |
| 430 | |
| 431 | sub autoflush { |
| 432 | my $old = new SelectSaver qualify($_[0], caller); |
| 433 | my $prev = $|; |
| 434 | $| = @_ > 1 ? $_[1] : 1; |
| 435 | $prev; |
| 436 | } |
| 437 | |
| 438 | sub output_field_separator { |
| 439 | my $old = new SelectSaver qualify($_[0], caller); |
| 440 | my $prev = $,; |
| 441 | $, = $_[1] if @_ > 1; |
| 442 | $prev; |
| 443 | } |
| 444 | |
| 445 | sub output_record_separator { |
| 446 | my $old = new SelectSaver qualify($_[0], caller); |
| 447 | my $prev = $\; |
| 448 | $\ = $_[1] if @_ > 1; |
| 449 | $prev; |
| 450 | } |
| 451 | |
| 452 | sub input_record_separator { |
| 453 | my $old = new SelectSaver qualify($_[0], caller); |
| 454 | my $prev = $/; |
| 455 | $/ = $_[1] if @_ > 1; |
| 456 | $prev; |
| 457 | } |
| 458 | |
| 459 | sub input_line_number { |
| 460 | my $old = new SelectSaver qualify($_[0], caller); |
| 461 | my $prev = $.; |
| 462 | $. = $_[1] if @_ > 1; |
| 463 | $prev; |
| 464 | } |
| 465 | |
| 466 | sub format_page_number { |
| 467 | my $old = new SelectSaver qualify($_[0], caller); |
| 468 | my $prev = $%; |
| 469 | $% = $_[1] if @_ > 1; |
| 470 | $prev; |
| 471 | } |
| 472 | |
| 473 | sub format_lines_per_page { |
| 474 | my $old = new SelectSaver qualify($_[0], caller); |
| 475 | my $prev = $=; |
| 476 | $= = $_[1] if @_ > 1; |
| 477 | $prev; |
| 478 | } |
| 479 | |
| 480 | sub format_lines_left { |
| 481 | my $old = new SelectSaver qualify($_[0], caller); |
| 482 | my $prev = $-; |
| 483 | $- = $_[1] if @_ > 1; |
| 484 | $prev; |
| 485 | } |
| 486 | |
| 487 | sub format_name { |
| 488 | my $old = new SelectSaver qualify($_[0], caller); |
| 489 | my $prev = $~; |
| 490 | $~ = qualify($_[1], caller) if @_ > 1; |
| 491 | $prev; |
| 492 | } |
| 493 | |
| 494 | sub format_top_name { |
| 495 | my $old = new SelectSaver qualify($_[0], caller); |
| 496 | my $prev = $^; |
| 497 | $^ = qualify($_[1], caller) if @_ > 1; |
| 498 | $prev; |
| 499 | } |
| 500 | |
| 501 | sub format_line_break_characters { |
| 502 | my $old = new SelectSaver qualify($_[0], caller); |
| 503 | my $prev = $:; |
| 504 | $: = $_[1] if @_ > 1; |
| 505 | $prev; |
| 506 | } |
| 507 | |
| 508 | sub format_formfeed { |
| 509 | my $old = new SelectSaver qualify($_[0], caller); |
| 510 | my $prev = $^L; |
| 511 | $^L = $_[1] if @_ > 1; |
| 512 | $prev; |
| 513 | } |
| 514 | |
| 515 | sub formline { |
| 516 | my $fh = shift; |
| 517 | my $picture = shift; |
| 518 | local($^A) = $^A; |
| 519 | local($\) = ""; |
| 520 | formline($picture, @_); |
| 521 | print $fh $^A; |
| 522 | } |
| 523 | |
| 524 | sub format_write { |
| 525 | @_ < 3 || croak 'usage: $fh->write( [FORMAT_NAME] )'; |
| 526 | if (@_ == 2) { |
| 527 | my ($fh, $fmt) = @_; |
| 528 | my $oldfmt = $fh->format_name($fmt); |
| 529 | write($fh); |
| 530 | $fh->format_name($oldfmt); |
| 531 | } else { |
| 532 | write($_[0]); |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | sub fcntl { |
| 537 | @_ == 3 || croak 'usage: $fh->fcntl( OP, VALUE );'; |
| 538 | my ($fh, $op, $val) = @_; |
| 539 | my $r = fcntl($fh, $op, $val); |
| 540 | defined $r && $r eq "0 but true" ? 0 : $r; |
| 541 | } |
| 542 | |
| 543 | sub ioctl { |
| 544 | @_ == 3 || croak 'usage: $fh->ioctl( OP, VALUE );'; |
| 545 | my ($fh, $op, $val) = @_; |
| 546 | my $r = ioctl($fh, $op, $val); |
| 547 | defined $r && $r eq "0 but true" ? 0 : $r; |
| 548 | } |
| 549 | |
| 550 | 1; |