stdio/stdio.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      ISO C Standard: 4.9 INPUT/OUTPUT        <stdio.h>
  21  */
  22
  23 #ifndef _STDIO_H
  24
  25 #if     !defined(__need_FILE)
  26 #define _STDIO_H        1
  27 #include <features.h>
  28
  29 __BEGIN_DECLS
  30
  31 #define __need_size_t
  32 #define __need_NULL
  33 #include <stddef.h>
  34
  35 #define __need___va_list
  36 #include <stdarg.h>
  37 #ifndef __GNUC_VA_LIST
  38 #define __gnuc_va_list  __ptr_t
  39 #endif
  40
  41 #include <gnu/types.h>
  42 #endif /* Don't need FILE.  */
  43 #undef  __need_FILE
  44
  45
  46 #ifndef __FILE_defined
  47
  48 /* The opaque type of streams.  */
  49 typedef struct __stdio_file FILE;
  50
  51 #define __FILE_defined  1
  52 #endif /* FILE not defined.  */
  53
  54
  55 #ifdef  _STDIO_H
  56
  57 /* The type of the second argument to `fgetpos' and `fsetpos'.  */
  58 typedef __off_t fpos_t;
  59
  60 /* The mode of I/O, as given in the MODE argument to fopen, etc.  */
  61 typedef struct
  62 {
  63   unsigned int __read:1;        /* Open for reading.  */
  64   unsigned int __write:1;       /* Open for writing.  */
  65   unsigned int __append:1;      /* Open for appending.  */
  66   unsigned int __binary:1;      /* Opened binary.  */
  67   unsigned int __create:1;      /* Create the file.  */
  68   unsigned int __exclusive:1;   /* Error if it already exists.  */
  69   unsigned int __truncate:1;    /* Truncate the file on opening.  */
  70 } __io_mode;
  71
  72
  73 /* Functions to do I/O and file management for a stream.  */
  74
  75 /* Read NBYTES bytes from COOKIE into a buffer pointed to by BUF.
  76    Return number of bytes read.  */
  77 typedef __ssize_t __io_read_fn __P ((__ptr_t __cookie, char *__buf,
  78                                      size_t __nbytes));
  79
  80 /* Write N bytes pointed to by BUF to COOKIE.  Write all N bytes
  81    unless there is an error.  Return number of bytes written, or -1 if
  82    there is an error without writing anything.  If the file has been
  83    opened for append (__mode.__append set), then set the file pointer
  84    to the end of the file and then do the write; if not, just write at
  85    the current file pointer.  */
  86 typedef __ssize_t __io_write_fn __P ((__ptr_t __cookie, __const char *__buf,
  87                                       size_t __n));
  88
  89 /* Move COOKIE's file position to *POS bytes from the
  90    beginning of the file (if W is SEEK_SET),
  91    the current position (if W is SEEK_CUR),
  92    or the end of the file (if W is SEEK_END).
  93    Set *POS to the new file position.
  94    Returns zero if successful, nonzero if not.  */
  95 typedef int __io_seek_fn __P ((__ptr_t __cookie, fpos_t *__pos, int __w));
  96
  97 /* Close COOKIE.  */
  98 typedef int __io_close_fn __P ((__ptr_t __cookie));
  99
 100 /* Return the file descriptor associated with COOKIE,
 101    or -1 on error.  There need not be any associated file descriptor.  */
 102 typedef int __io_fileno_fn __P ((__ptr_t __cookie));
 103
 104 #ifdef __USE_GNU
 105 /* User-visible names for the above.  */
 106 typedef __io_read_fn cookie_read_function_t;
 107 typedef __io_write_fn cookie_write_function_t;
 108 typedef __io_seek_fn cookie_seek_function_t;
 109 typedef __io_close_fn cookie_close_function_t;
 110 typedef __io_fileno_fn cookie_fileno_function_t;
 111 #endif
 112
 113 /* Low level interface, independent of FILE representation.  */
 114 #if defined (__USE_GNU) && !defined (_LIBC)
 115 /* Define the user-visible type, with user-friendly member names.  */
 116 typedef struct
 117 {
 118   __io_read_fn *read;           /* Read bytes.  */
 119   __io_write_fn *write;         /* Write bytes.  */
 120   __io_seek_fn *seek;           /* Seek/tell file position.  */
 121   __io_close_fn *close;         /* Close file.  */
 122   __io_fileno_fn *fileno;       /* Return file descriptor.  */
 123 } cookie_io_functions_t;
 124 /* This name is still used in the prototypes in this file.  */
 125 typedef cookie_io_functions_t __io_functions;
 126 #else
 127 /* Stick to ANSI-safe names.  */
 128 typedef struct
 129 {
 130   __io_read_fn *__read;         /* Read bytes.  */
 131   __io_write_fn *__write;       /* Write bytes.  */
 132   __io_seek_fn *__seek;         /* Seek/tell file position.  */
 133   __io_close_fn *__close;       /* Close file.  */
 134   __io_fileno_fn *__fileno;     /* Return file descriptor.  */
 135 } __io_functions;
 136 #endif
 137
 138 /* Higher level interface, dependent on FILE representation.  */
 139 typedef struct
 140 {
 141   /* Make room in the input buffer.  */
 142   int (*__input) __P ((FILE *__stream));
 143   /* Make room in the output buffer.  */
 144   void (*__output) __P ((FILE *__stream, int __c));
 145 } __room_functions;
 146
 147 extern __const __io_functions __default_io_functions;
 148 extern __const __room_functions __default_room_functions;
 149
 150
 151 /* Default close function.  */
 152 extern __io_close_fn __stdio_close;
 153 /* Open FILE with mode M, store cookie in *COOKIEPTR.  */
 154 extern int __stdio_open __P ((__const char *__file, __io_mode __m,
 155                               __ptr_t *__cookieptr));
 156 /* Put out an error message for when stdio needs to die.  */
 157 extern void __stdio_errmsg __P ((__const char *__msg, size_t __len));
 158 /* Generate a unique file name (and possibly open it with mode "w+b").  */
 159 extern char *__stdio_gen_tempname __P ((char *__buf, size_t __bufsize,
 160                                         __const char *__dir,
 161                                         __const char *__pfx,
 162                                         int __dir_search,
 163                                         size_t *__lenptr,
 164                                         FILE **__streamptr));
 165
 166
 167 /* Print out MESSAGE on the error output and abort.  */
 168 extern void __libc_fatal __P ((__const char *__message))
 169      __attribute__ ((__noreturn__));
 170
 171
 172 /* For thread safe I/O functions we need a lock in each stream.  We
 173    keep the type opaque here.  */
 174 struct __stdio_lock;
 175
 176 /* The FILE structure.  */
 177 struct __stdio_file
 178 {
 179   /* Magic number for validation.  Must be negative in open streams
 180      for the glue to Unix stdio getc/putc to work.
 181      NOTE: stdio/glue.c has special knowledge of these first four members.  */
 182   int __magic;
 183 #define _IOMAGIC ((int) 0xfedabeeb)     /* Magic number to fill `__magic'.  */
 184 #define _GLUEMAGIC ((int) 0xfeedbabe)   /* Magic for glued Unix streams.  */
 185
 186   char *__bufp;                 /* Pointer into the buffer.  */
 187   char *__get_limit;            /* Reading limit.  */
 188   char *__put_limit;            /* Writing limit.  */
 189
 190   char *__buffer;               /* Base of buffer.  */
 191   size_t __bufsize;             /* Size of the buffer.  */
 192   __ptr_t __cookie;             /* Magic cookie.  */
 193   __io_mode __mode;             /* File access mode.  */
 194   __io_functions __io_funcs;    /* I/O functions.  */
 195   __room_functions __room_funcs;/* I/O buffer room functions.  */
 196   fpos_t __offset;              /* Current file position.  */
 197   fpos_t __target;              /* Target file position.  */
 198   FILE *__next;                 /* Next FILE in the linked list.  */
 199   char *__pushback_bufp;        /* Old bufp if char pushed back.  */
 200   unsigned char __pushback;     /* Pushed-back character.  */
 201   unsigned int __pushed_back:1; /* A char has been pushed back.  */
 202   unsigned int __eof:1;         /* End of file encountered.  */
 203   unsigned int __error:1;       /* Error encountered.  */
 204   unsigned int __userbuf:1;     /* Buffer from user (should not be freed).  */
 205   unsigned int __linebuf:1;     /* Flush on newline.  */
 206   unsigned int __linebuf_active:1; /* put_limit is not really in use.  */
 207   unsigned int __seen:1;        /* This stream has been seen.  */
 208   unsigned int __ispipe:1;      /* Nonzero if opened by popen.  */
 209   struct __stdio_lock *__lock;  /* Pointer to associated lock.  */
 210 };
 211
 212
 213 /* All macros used internally by other macros here and by stdio functions begin
 214    with `__'.  All of these may evaluate their arguments more than once.  */
 215
 216
 217 /* Nonzero if STREAM is a valid stream.
 218    STREAM must be a modifiable lvalue (wow, I got to use that term).
 219    See stdio/glue.c for what the confusing bit is about.  */
 220 #define __validfp(stream)                                                     \
 221   (stream != NULL &&                                                          \
 222    ({ if (stream->__magic == _GLUEMAGIC)                                      \
 223         stream = *((struct { int __magic; FILE **__p; } *) stream)->__p;      \
 224       stream->__magic == _IOMAGIC; }))
 225
 226 /* Clear the error and EOF indicators of STREAM.  */
 227 #define __clearerr(stream)      ((stream)->__error = (stream)->__eof = 0)
 228
 229 /* Nuke STREAM, making it unusable but available for reuse.  */
 230 extern void __invalidate __P ((FILE *__stream));
 231
 232 /* Make sure STREAM->__offset and STREAM->__target are initialized.
 233    Returns 0 if successful, or EOF on
 234    error (but doesn't set STREAM->__error).  */
 235 extern int __stdio_check_offset __P ((FILE *__stream));
 236
 237
 238 /* The possibilities for the third argument to `setvbuf'.  */
 239 #define _IOFBF  0x1             /* Full buffering.  */
 240 #define _IOLBF  0x2             /* Line buffering.  */
 241 #define _IONBF  0x4             /* No buffering.  */
 242
 243
 244 /* Default buffer size.  */
 245 #define BUFSIZ  1024
 246
 247
 248 /* End of file character.
 249    Some things throughout the library rely on this being -1.  */
 250 #define EOF     (-1)
 251
 252
 253 /* The possibilities for the third argument to `fseek'.
 254    These values should not be changed.  */
 255 #define SEEK_SET        0       /* Seek from beginning of file.  */
 256 #define SEEK_CUR        1       /* Seek from current position.  */
 257 #define SEEK_END        2       /* Seek from end of file.  */
 258
 259
 260 #ifdef  __USE_SVID
 261 /* Default path prefix for `tempnam' and `tmpnam'.  */
 262 #define P_tmpdir        "/usr/tmp"
 263 #endif
 264
 265
 266 /* Get the values:
 267    L_tmpnam     How long an array of chars must be to be passed to `tmpnam'.
 268    TMP_MAX      The minimum number of unique filenames generated by tmpnam
 269                 (and tempnam when it uses tmpnam's name space),
 270                 or tempnam (the two are separate).
 271    L_ctermid    How long an array to pass to `ctermid'.
 272    L_cuserid    How long an array to pass to `cuserid'.
 273    FOPEN_MAX    Minimum number of files that can be open at once.
 274    FILENAME_MAX Maximum length of a filename.  */
 275 #include <stdio_lim.h>
 276
 277
 278 /* All the known streams are in a linked list
 279    linked by the `next' field of the FILE structure.  */
 280 extern FILE *__stdio_head;      /* Head of the list.  */
 281
 282 /* Standard streams.  */
 283 extern FILE *stdin, *stdout, *stderr;
 284 #ifdef __STRICT_ANSI__
 285 /* ANSI says these are macros; satisfy pedants.  */
 286 #define stdin   stdin
 287 #define stdout  stdout
 288 #define stderr  stderr
 289 #endif
 290
 291
 292 /* Remove file FILENAME.  */
 293 extern int remove __P ((__const char *__filename));
 294 /* Rename file OLD to NEW.  */
 295 extern int rename __P ((__const char *__old, __const char *__new));
 296
 297
 298 /* Create a temporary file and open it read/write.  */
 299 extern FILE *tmpfile __P ((void));
 300 /* Generate a temporary filename.  */
 301 extern char *tmpnam __P ((char *__s));
 302
 303 #ifdef __USE_REENTRANT
 304 /* This is the reentrant variant of `tmpnam'.  The only difference is
 305    that it does not allow S to be NULL.  */
 306 extern char *tmpnam_r __P ((char *__s));
 307 #endif
 308
 309
 310 #if defined(__USE_SVID) || defined(__USE_XOPEN)
 311 /* Generate a unique temporary filename using up to five characters of PFX
 312    if it is not NULL.  The directory to put this file in is searched for
 313    as follows: First the environment variable "TMPDIR" is checked.
 314    If it contains the name of a writable directory, that directory is used.
 315    If not and if DIR is not NULL, that value is checked.  If that fails,
 316    P_tmpdir is tried and finally "/tmp".  The storage for the filename
 317    is allocated by `malloc'.  */
 318 extern char *tempnam __P ((__const char *__dir, __const char *__pfx));
 319 #endif
 320
 321
 322 /* This performs actual output when necessary, flushing
 323    STREAM's buffer and optionally writing another character.  */
 324 extern int __flshfp __P ((FILE *__stream, int __c));
 325
 326
 327 /* Close STREAM.  */
 328 extern int fclose __P ((FILE *__stream));
 329 /* Flush STREAM, or all streams if STREAM is NULL.  */
 330 extern int fflush __P ((FILE *__stream));
 331
 332 #ifdef __USE_GNU
 333 /* Close all streams.  */
 334 extern int __fcloseall __P ((void));
 335 extern int fcloseall __P ((void));
 336 #endif
 337
 338
 339 /* Open a file and create a new stream for it.  */
 340 extern FILE *fopen __P ((__const char *__filename, __const char *__modes));
 341 /* Open a file, replacing an existing stream with it. */
 342 extern FILE *freopen __P ((__const char *__filename,
 343                            __const char *__modes, FILE *__stream));
 344
 345 /* Return a new, zeroed, stream.
 346    You must set its cookie and io_mode.
 347    The first operation will give it a buffer unless you do.
 348    It will also give it the default functions unless you set the `seen' flag.
 349    The offset is set to -1, meaning it will be determined by doing a
 350    stationary seek.  You can set it to avoid the initial tell call.
 351    The target is set to -1, meaning it will be set to the offset
 352    before the target is needed.
 353    Returns NULL if a stream can't be created.  */
 354 extern FILE *__newstream __P ((void));
 355
 356 #ifdef  __USE_POSIX
 357 /* Create a new stream that refers to an existing system file descriptor.  */
 358 extern FILE *fdopen __P ((int __fd, __const char *__modes));
 359 #endif
 360
 361 #ifdef  __USE_GNU
 362 /* Create a new stream that refers to the given magic cookie,
 363    and uses the given functions for input and output.  */
 364 extern FILE *fopencookie __P ((__ptr_t __magic_cookie, __const char *__modes,
 365                                __io_functions __io_funcs));
 366
 367 /* Create a new stream that refers to a memory buffer.  */
 368 extern FILE *fmemopen __P ((__ptr_t __s, size_t __len, __const char *__modes));
 369
 370 /* Open a stream that writes into a malloc'd buffer that is expanded as
 371    necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
 372    and the number of characters written on fflush or fclose.  */
 373 extern FILE *open_memstream __P ((char **__bufloc, size_t *__sizeloc));
 374 #endif
 375
 376
 377 /* If BUF is NULL, make STREAM unbuffered.
 378    Else make it use buffer BUF, of size BUFSIZ.  */
 379 extern void setbuf __P ((FILE *__stream, char *__buf));
 380 /* Make STREAM use buffering mode MODE.
 381    If BUF is not NULL, use N bytes of it for buffering;
 382    else allocate an internal buffer N bytes long.  */
 383 extern int setvbuf __P ((FILE *__stream, char *__buf,
 384                          int __modes, size_t __n));
 385
 386 #ifdef  __USE_BSD
 387 /* If BUF is NULL, make STREAM unbuffered.
 388    Else make it use SIZE bytes of BUF for buffering.  */
 389 extern void setbuffer __P ((FILE *__stream, char *__buf, size_t __size));
 390
 391 /* Make STREAM line-buffered.  */
 392 extern void setlinebuf __P ((FILE *__stream));
 393 #endif
 394
 395
 396 /* Write formatted output to STREAM.  */
 397 extern int fprintf __P ((FILE *__stream, __const char *__format, ...));
 398 /* Write formatted output to stdout.  */
 399 extern int printf __P ((__const char *__format, ...));
 400 /* Write formatted output to S.  */
 401 extern int sprintf __P ((char *__s, __const char *__format, ...));
 402
 403 /* Write formatted output to S from argument list ARG.  */
 404 extern int vfprintf __P ((FILE *__s, __const char *__format,
 405                           __gnuc_va_list __arg));
 406 /* Write formatted output to stdout from argument list ARG.  */
 407 extern int vprintf __P ((__const char *__format, __gnuc_va_list __arg));
 408 /* Write formatted output to S from argument list ARG.  */
 409 extern int vsprintf __P ((char *__s, __const char *__format,
 410                           __gnuc_va_list __arg));
 411
 412 #ifdef  __OPTIMIZE__
 413 extern __inline int
 414 vprintf (const char *__fmt, __gnuc_va_list __arg)
 415 {
 416   return vfprintf (stdout, __fmt, __arg);
 417 }
 418 #endif /* Optimizing.  */
 419
 420 #ifdef  __USE_GNU
 421 /* Maximum chars of output to write in MAXLEN.  */
 422 extern int __snprintf __P ((char *__s, size_t __maxlen,
 423                             __const char *__format, ...));
 424 extern int snprintf __P ((char *__s, size_t __maxlen,
 425                           __const char *__format, ...));
 426
 427 extern int __vsnprintf __P ((char *__s, size_t __maxlen,
 428                              __const char *__format, __gnuc_va_list __arg));
 429 extern int vsnprintf __P ((char *__s, size_t __maxlen,
 430                            __const char *__format, __gnuc_va_list __arg));
 431
 432 /* Write formatted output to a string dynamically allocated with `malloc'.
 433    Store the address of the string in *PTR.  */
 434 extern int vasprintf __P ((char **__ptr, __const char *__f,
 435                            __gnuc_va_list __arg));
 436 extern int asprintf __P ((char **__ptr, __const char *__fmt, ...));
 437
 438 /* Write formatted output to a file descriptor.  */
 439 extern int vdprintf __P ((int __fd, __const char *__fmt,
 440                           __gnuc_va_list __arg));
 441 extern int dprintf __P ((int __fd, __const char *__fmt, ...));
 442 #endif
 443
 444
 445 /* Read formatted input from STREAM.  */
 446 extern int fscanf __P ((FILE *__stream, __const char *__format, ...));
 447 /* Read formatted input from stdin.  */
 448 extern int scanf __P ((__const char *__format, ...));
 449 /* Read formatted input from S.  */
 450 extern int sscanf __P ((__const char *__s, __const char *__format, ...));
 451
 452 #ifdef  __USE_GNU
 453 /* Read formatted input from S into argument list ARG.  */
 454 extern int __vfscanf __P ((FILE *__s, __const char *__format,
 455                            __gnuc_va_list __arg));
 456 extern int vfscanf __P ((FILE *__s, __const char *__format,
 457                          __gnuc_va_list __arg));
 458
 459 /* Read formatted input from stdin into argument list ARG.  */
 460 extern int __vscanf __P ((__const char *__format, __gnuc_va_list __arg));
 461 extern int vscanf __P ((__const char *__format, __gnuc_va_list __arg));
 462
 463 /* Read formatted input from S into argument list ARG.  */
 464 extern int __vsscanf __P ((__const char *__s, __const char *__format,
 465                            __gnuc_va_list __arg));
 466 extern int vsscanf __P ((__const char *__s, __const char *__format,
 467                          __gnuc_va_list __arg));
 468
 469
 470 #ifdef  __OPTIMIZE__
 471 extern __inline int
 472 vfscanf (FILE *__s, const char *__fmt, __gnuc_va_list __arg)
 473 {
 474   return __vfscanf (__s, __fmt, __arg);
 475 }
 476 extern __inline int
 477 vscanf (const char *__fmt, __gnuc_va_list __arg)
 478 {
 479   return __vfscanf (stdin, __fmt, __arg);
 480 }
 481 extern __inline int
 482 vsscanf (const char *__s, const char *__fmt, __gnuc_va_list __arg)
 483 {
 484   return __vsscanf (__s, __fmt, __arg);
 485 }
 486 #endif /* Optimizing.  */
 487 #endif /* Use GNU.  */
 488
 489
 490 /* This does actual reading when necessary, filling STREAM's
 491    buffer and returning the first character in it.  */
 492 extern int __fillbf __P ((FILE *__stream));
 493
 494
 495 /* Read a character from STREAM.  */
 496 extern int fgetc __P ((FILE *__stream));
 497 extern int getc __P ((FILE *__stream));
 498
 499 /* Read a character from stdin.  */
 500 extern int getchar __P ((void));
 501
 502 /* The C standard explicitly says this can
 503    re-evaluate its argument, so it does. */
 504 #define __getc(stream)                                                        \
 505   ((stream)->__bufp < (stream)->__get_limit ?                                 \
 506    (int) ((unsigned char) *(stream)->__bufp++) : __fillbf(stream))
 507
 508 /* The C standard explicitly says this is a macro,
 509    so we always do the optimization for it.  */
 510 #define getc(stream)    __getc(stream)
 511
 512 #ifdef  __OPTIMIZE__
 513 extern __inline int
 514 getchar (void)
 515 {
 516   return __getc (stdin);
 517 }
 518 #endif /* Optimizing.  */
 519
 520
 521 /* Write a character to STREAM.  */
 522 extern int fputc __P ((int __c, FILE *__stream));
 523 extern int putc __P ((int __c, FILE *__stream));
 524
 525 /* Write a character to stdout.  */
 526 extern int putchar __P ((int __c));
 527
 528
 529 /* The C standard explicitly says this can
 530    re-evaluate its arguments, so it does.  */
 531 #define __putc(c, stream)                                                     \
 532   ((stream)->__bufp < (stream)->__put_limit ?                                 \
 533    (int) (unsigned char) (*(stream)->__bufp++ = (unsigned char) (c)) :        \
 534    __flshfp ((stream), (unsigned char) (c)))
 535
 536 /* The C standard explicitly says this can be a macro,
 537    so we always do the optimization for it.  */
 538 #define putc(c, stream) __putc ((c), (stream))
 539
 540 #ifdef __OPTIMIZE__
 541 extern __inline int
 542 putchar (int __c)
 543 {
 544   return __putc (__c, stdout);
 545 }
 546 #endif
 547
 548
 549 #if defined(__USE_SVID) || defined(__USE_MISC)
 550 /* Get a word (int) from STREAM.  */
 551 extern int getw __P ((FILE *__stream));
 552
 553 /* Write a word (int) to STREAM.  */
 554 extern int putw __P ((int __w, FILE *__stream));
 555 #endif
 556
 557
 558 /* Get a newline-terminated string of finite length from STREAM.  */
 559 extern char *fgets __P ((char *__s, int __n, FILE *__stream));
 560
 561 /* Get a newline-terminated string from stdin, removing the newline.
 562    DO NOT USE THIS FUNCTION!!  There is no limit on how much it will read.  */
 563 extern char *gets __P ((char *__s));
 564
 565
 566 #ifdef  __USE_GNU
 567 #include <sys/types.h>
 568
 569 /* Read up to (and including) a DELIMITER from STREAM into *LINEPTR
 570    (and null-terminate it). *LINEPTR is a pointer returned from malloc (or
 571    NULL), pointing to *N characters of space.  It is realloc'd as
 572    necessary.  Returns the number of characters read (not including the
 573    null terminator), or -1 on error or EOF.  */
 574 ssize_t __getdelim __P ((char **__lineptr, size_t *__n,
 575                          int __delimiter, FILE *__stream));
 576 ssize_t getdelim __P ((char **__lineptr, size_t *__n,
 577                        int __delimiter, FILE *__stream));
 578
 579 /* Like `getdelim', but reads up to a newline.  */
 580 ssize_t __getline __P ((char **__lineptr, size_t *__n, FILE *__stream));
 581 ssize_t getline __P ((char **__lineptr, size_t *__n, FILE *__stream));
 582
 583 #ifdef  __OPTIMIZE__
 584 extern __inline ssize_t
 585 __getline (char **__lineptr, size_t *__n, FILE *__stream)
 586 {
 587   return __getdelim (__lineptr, __n, '\n', __stream);
 588 }
 589
 590 extern __inline ssize_t
 591 getdelim (char **__lineptr, size_t *__n, int __delimiter, FILE *__stream)
 592 {
 593   return __getdelim (__lineptr, __n, __delimiter, __stream);
 594 }
 595 extern __inline ssize_t
 596 getline (char **__lineptr, size_t *__n, FILE *__stream)
 597 {
 598   return __getline (__lineptr, __n, __stream);
 599 }
 600 #endif /* Optimizing.  */
 601 #endif
 602
 603
 604 /* Write a string to STREAM.  */
 605 extern int fputs __P ((__const char *__s, FILE *__stream));
 606 /* Write a string, followed by a newline, to stdout.  */
 607 extern int puts __P ((__const char *__s));
 608
 609
 610 /* Push a character back onto the input buffer of STREAM.  */
 611 extern int ungetc __P ((int __c, FILE *__stream));
 612
 613
 614 /* Read chunks of generic data from STREAM.  */
 615 extern size_t fread __P ((__ptr_t __ptr, size_t __size,
 616                           size_t __n, FILE *__stream));
 617 /* Write chunks of generic data to STREAM.  */
 618 extern size_t fwrite __P ((__const __ptr_t __ptr, size_t __size,
 619                            size_t __n, FILE *__s));
 620
 621
 622 /* Seek to a certain position on STREAM.  */
 623 extern int fseek __P ((FILE *__stream, long int __off, int __whence));
 624 /* Return the current position of STREAM.  */
 625 extern long int ftell __P ((FILE *__stream));
 626 /* Rewind to the beginning of STREAM.  */
 627 extern void rewind __P ((FILE *__stream));
 628
 629 /* Get STREAM's position.  */
 630 extern int fgetpos __P ((FILE *__stream, fpos_t *__pos));
 631 /* Set STREAM's position.  */
 632 extern int fsetpos __P ((FILE *__stream, __const fpos_t *__pos));
 633
 634
 635 /* Clear the error and EOF indicators for STREAM.  */
 636 extern void clearerr __P ((FILE *__stream));
 637 /* Return the EOF indicator for STREAM.  */
 638 extern int feof __P ((FILE *__stream));
 639 /* Return the error indicator for STREAM.  */
 640 extern int ferror __P ((FILE *__stream));
 641
 642 #ifdef  __OPTIMIZE__
 643 #define feof(stream)    ((stream)->__eof != 0)
 644 #define ferror(stream)  ((stream)->__error != 0)
 645 #endif /* Optimizing.  */
 646
 647
 648 /* Print a message describing the meaning of the value of errno.  */
 649 extern void perror __P ((__const char *__s));
 650
 651 #ifdef  __USE_BSD
 652 extern int sys_nerr;
 653 extern const char *const sys_errlist[];
 654 #endif
 655 #ifdef  __USE_GNU
 656 extern int _sys_nerr;
 657 extern const char *const _sys_errlist[];
 658 #endif
 659
 660
 661 #ifdef  __USE_POSIX
 662 /* Return the system file descriptor for STREAM.  */
 663 extern int fileno __P ((FILE *__stream));
 664 #endif /* Use POSIX.  */
 665
 666
 667 #if (defined (__USE_POSIX2) || defined(__USE_SVID) || defined(__USE_BSD) || \
 668      defined(__USE_MISC))
 669 /* Create a new stream connected to a pipe running the given command.  */
 670 extern FILE *popen __P ((__const char *__command, __const char *__modes));
 671
 672 /* Close a stream opened by popen and return the status of its child.  */
 673 extern int pclose __P ((FILE *__stream));
 674 #endif
 675
 676
 677 #ifdef  __USE_POSIX
 678 /* Return the name of the controlling terminal.  */
 679 extern char *ctermid __P ((char *__s));
 680 #endif
 681
 682
 683 #ifdef __USE_XOPEN
 684 /* Return the name of the current user.  */
 685 extern char *cuserid __P ((char *__s));
 686 #endif
 687
 688
 689 #ifdef  __USE_GNU
 690 struct obstack;                 /* See <obstack.h>.  */
 691
 692 /* Open a stream that writes to OBSTACK.  */
 693 extern FILE *open_obstack_stream __P ((struct obstack *__obstack));
 694
 695 /* Write formatted output to an obstack.  */
 696 extern int obstack_printf __P ((struct obstack *__obstack,
 697                                 __const char *__format, ...));
 698 extern int obstack_vprintf __P ((struct obstack *__obstack,
 699                                  __const char *__format,
 700                                  __gnuc_va_list __args));
 701 #endif
 702
 703
 704 __END_DECLS
 705
 706 #endif /* <stdio.h> included.  */
 707
 708 #endif /* stdio.h  */