3 /* Input/output <stdio.h>
5 This file is part of the Public Domain C Library (PDCLib).
6 Permission is granted to use, modify, and / or redistribute at will.
9 #ifndef _PDCLIB_STDIO_H
10 #define _PDCLIB_STDIO_H _PDCLIB_STDIO_H
13 #define _PDCLIB_INT_H _PDCLIB_INT_H
14 #include <_PDCLIB_int.h>
17 #ifndef _PDCLIB_SIZE_T_DEFINED
18 #define _PDCLIB_SIZE_T_DEFINED _PDCLIB_SIZE_T_DEFINED
19 typedef _PDCLIB_size_t size_t;
22 #ifndef _PDCLIB_NULL_DEFINED
23 #define _PDCLIB_NULL_DEFINED _PDCLIB_NULL_DEFINED
24 #define NULL _PDCLIB_NULL
27 /* See setvbuf(), third argument */
32 /* The following are platform-dependant, and defined in _PDCLIB_config.h. */
33 typedef struct _PDCLIB_fpos_t fpos_t;
34 typedef struct _PDCLIB_file_t FILE;
36 #define BUFSIZ _PDCLIB_BUFSIZ
37 #define FOPEN_MAX _PDCLIB_FOPEN_MAX
38 #define FILENAME_MAX _PDCLIB_FILENAME_MAX
39 #define L_tmpnam _PDCLIB_L_tmpnam
40 #define TMP_MAX _PDCLIB_TMP_MAX
42 /* See fseek(), third argument */
43 #define SEEK_CUR _PDCLIB_SEEK_CUR
44 #define SEEK_END _PDCLIB_SEEK_END
45 #define SEEK_SET _PDCLIB_SEEK_SET
51 /* Operations on files */
53 /* Remove the given file.
54 Returns zero if successful, non-zero otherwise.
55 This implementation does detect if a file of that name is currently open,
56 and fails the remove in this case. This does not detect two distinct names
57 that merely result in the same file (e.g. "/home/user/foo" vs. "~/foo").
59 int remove( const char * filename );
61 /* Rename the given old file to the given new name.
62 Returns zero if successful, non-zero otherwise.
63 This implementation does detect if the old filename corresponds to an open
64 file, and fails the rename in this case.
65 If there already is a file with the new filename, behaviour is defined by
66 the glue code (see functions/_PDCLIB/rename.c).
68 int rename( const char * old, const char * new );
70 /* Open a temporary file with mode "wb+", i.e. binary-update. Remove the file
71 automatically if it is closed or the program exits normally (by returning
72 from main() or calling exit()).
73 Returns a pointer to a FILE handle for this file.
74 This implementation does not remove temporary files if the process aborts
75 abnormally (e.g. abort()).
77 FILE * tmpfile( void );
79 /* Generate a file name that is not equal to any existing filename AT THE TIME
80 OF GENERATION. Generate a different name each time it is called.
81 Returns a pointer to an internal static buffer containing the filename if s
82 is a NULL pointer. (This is not thread-safe!)
83 Returns s if it is not a NULL pointer (s is then assumed to point to an array
84 of at least L_tmpnam characters).
85 Returns NULL if unable to generate a suitable name (because all possible
86 names already exist, or the function has been called TMP_MAX times already).
87 Note that this implementation cannot guarantee a file of the name generated
88 is not generated between the call to this function and a subsequent fopen().
90 char * tmpnam( char * s );
92 /* File access functions */
94 /* Close the file associated with the given stream (after flushing its buffers).
95 Returns zero if successful, EOF if any errors occur.
97 int fclose( FILE * stream );
99 /* Flush the buffers of the given output stream. If the stream is an input
100 stream, or an update stream with the last operation being an input operation,
101 behaviour is undefined.
102 If stream is a NULL pointer, perform the buffer flushing for all applicable
104 Returns zero if successful, EOF if a write error occurs.
105 Sets the error indicator of the stream if a write error occurs.
107 int fflush( FILE * stream );
109 /* Open the file with the given filename in the given mode, and return a stream
110 handle for it in which error and end-of-file indicator are cleared. Defined
114 text files binary files
115 without update "r" "rb"
116 with update "r+" "rb+" or "r+b"
118 Opening in read mode fails if no file with the given filename exists, or if
122 text files binary files
123 without update "w" "wb"
124 with update "w+" "wb+" or "w+b"
126 With write modes, if a file with the given filename already exists, it is
127 truncated to zero length.
130 text files binary files
131 without update "a" "ab"
132 with update "a+" "ab+" or "a+b"
134 With update modes, if a file with the given filename already exists, it is
135 not truncated to zero length, but all writes are forced to end-of-file (this
136 regardless to fseek() calls). Note that binary files opened in append mode
137 might have their end-of-file padded with '\0' characters.
139 Update modes mean that both input and output functions can be performed on
140 the stream, but output must be terminated with a call to either fflush(),
141 fseek(), fsetpos(), or rewind() before input is performed, and input must
142 be terminated with a call to either fseek(), fsetpos(), or rewind() before
143 output is performed, unless input encountered end-of-file.
145 If a text file is opened with update mode, the implementation is at liberty
146 to open a binary stream instead. This implementation honors the exact mode
149 The stream is fully buffered if and only if it can be determined not to
150 refer to an interactive device.
152 If the mode string begins with but is longer than one of the above sequences
153 the implementation is at liberty to ignore the additional characters, or do
154 implementation-defined things. This implementation only accepts the exact
157 Returns a pointer to the stream handle if successfull, NULL otherwise.
159 FILE * fopen( const char * _PDCLIB_restrict filename, const char * _PDCLIB_restrict mode );
161 /* Close any file currently associated with the given stream. Open the file
162 identified by the given filename with the given mode (equivalent to fopen()),
163 and associate it with the given stream. If filename is a NULL pointer,
164 attempt to change the mode of the given stream.
165 This implementation allows the following mode changes: TODO
166 (Primary use of this function is to redirect stdin, stdout, and stderr.)
168 FILE * freopen( const char * _PDCLIB_restrict filename, const char * _PDCLIB_restrict mode, FILE * _PDCLIB_restrict stream );
170 /* If buf is a NULL pointer, call setvbuf( stream, NULL, _IONBF, BUFSIZ ).
171 If buf is not a NULL pointer, call setvbuf( stream, buf, _IOFBF, BUFSIZ ).
173 void setbuf( FILE * _PDCLIB_restrict stream, char * _PDCLIB_restrict buf );
175 /* Set the given stream to the given buffering mode. If buf is not a NULL
176 pointer, use buf as file buffer (of given size). If buf is a NULL pointer,
177 use a buffer of given size allocated internally. _IONBF causes unbuffered
178 behaviour, _IOLBF causes line-buffered behaviour, _IOFBF causes fully
179 buffered behaviour. Calling this function is only valid right after a file is
180 opened, and before any other operation (except for any unsuccessful calls to
181 setvbuf()) has been performed.
182 Returns zero if successful, nonzero otherwise.
184 int setvbuf( FILE * _PDCLIB_restrict stream, char * _PDCLIB_restrict buf, int mode, size_t size );
186 /* Formatted input/output functions */
189 Write output to the given stream, as defined by the given format string and
190 0..n subsequent arguments (the argument stack).
192 The format string is written to the given stream verbatim, except for any
193 conversion specifiers included, which start with the letter '%' and are
194 documented below. If the given conversion specifiers require more arguments
195 from the argument stack than provided, behaviour is undefined. Additional
196 arguments not required by conversion specifiers are evaluated but otherwise
199 (The standard specifies the format string is allowed to contain multibyte
200 character sequences as long as it starts and ends in initial shift state,
201 but this is not yet supported by this implementation, which interprets the
202 format string as sequence of char.)
203 TODO: Add multibyte support to printf() functions.
205 A conversion specifier consists of:
206 - Zero or more flags (one of the characters "-+ #0").
207 - Optional minimum field width as decimal integer. Default is padding to the
208 left, using spaces. Note that 0 is taken as a flag, not the beginning of a
209 field width. Note also that a small field width will not result in the
210 truncation of a value.
211 - Optional precision (given as ".#" with # being a decimal integer),
213 - the min. number of digits to appear (diouxX),
214 - the max. number of digits after the decimal point (aAeEfF),
215 - the max. number of significant digits (gG),
216 - the max. number of bytes to be written (s).
217 - behaviour with other conversion specifiers is undefined.
218 - Optional length modifier specifying the size of the argument (one of "hh",
219 "ll", or one of the characters "hljztL").
220 - Conversion specifier character specifying the type of conversion to be
221 applied (and the type of the next argument from the argument stack). One
222 of the characters "diouxXfFeEgGaAcspn%".
224 Minimum field width and/or precision may be given as asterisk ('*') instead
225 of a decimal integer. In this case, the next argument from the argument
226 stack is assumed to be an int value specifying the width / precision. A
227 negative field width is interpreted as flag '-' followed by a positive field
228 width. A negative precision is interpreted as if no precision was given.
231 - Left-justify the conversion result within its field width.
232 + Prefix a '+' on positive signed conversion results. Prefix a '-' on
233 floating conversions resulting in negative zero, or negative values
235 space Prefix a space on positive signed conversion results, or if a signed
236 conversion results in no characters. If both '+' and ' ' are given,
238 # Use an "alternative form" for
239 - 'o' conversion, increasing precision until the first digit of the
241 - 'x' or 'X' conversion, prefixing "0x" or "0X" to nonzero results;
242 - "aAeEfF" conversions, always printing a decimal point even if no
243 digits are following;
244 - 'g' or 'G' conversions, always printing a decimal point even if no
245 digits are following, and not removing trailing zeroes.
246 - behaviour for other conversions is unspecified.
247 0 Use leading zeroes instead of spaces for field width padding. If both
248 '-' and '0' are given, '0' is ignored. If a precision is specified for
249 any of the "diouxX" conversions, '0' is ignored. Behaviour is only
250 defined for "diouxXaAeEfFgG".
253 hh For "diouxX" conversions, the argument from the argument stack is
254 assumed to be of char width. (It will have been subject to integer
255 promotion but will be converted back.) For 'n' conversions, the argument
256 is assumed to be a pointer to signed char.
257 h For "diouxX" conversions, the argument from the argument stack is
258 assumed to be of short int width. (It will have been subject to integer
259 promotion but will be converted back.) For 'n' conversions, the argument
260 is assumed to be a pointer to short int.
261 l For "diouxX" conversions, the argument from the argument stack is
262 assumed to be of long int width. For 'n' conversions, the argument is
263 assumed to be a pointer to short int. For 'c' conversions, the argument
264 is assumed to be a wint_t. For 's' conversions, the argument is assumed
265 to be a pointer to wchar_t. No effect on "aAeEfFgG" conversions.
266 ll For "diouxX" conversions, the argument from the argument stack is
267 assumed to be of long long int width. For 'n' conversions, the argument
268 is assumed to be a pointer to long long int.
269 j For "diouxX" conversions, the argument from the argument stack is
270 assumed to be of intmax_t width. For 'n' conversions, the argument is
271 assumed to be a pointer to intmax_t.
272 z For "diouxX" conversions, the argument from the argument stack is
273 assumed to be of size_t width. For 'n' conversions, the argument is
274 assumed to be a pointer to size_t.
275 t For "diouxX" conversions, the argument from the argument stack is
276 assumed to be of ptrdiff_t width. For 'n' conversions, the argument is
277 assumed to be a pointer to ptrdiff_t.
278 L For "aAeEfFgG" conversions, the argument from the argument stack is
279 assumed to be a long double.
280 Length modifiers appearing for any conversions not mentioned above will have
282 If a length modifier appears with any conversion specifier other than as
283 specified above, the behavior is undefined.
285 CONVERSION SPECIFIERS
286 d,i The argument from the argument stack is assumed to be of type int, and
287 is converted to a signed decimal value with a minimum number of digits
288 as specified by the precision (default 1), padded with leading zeroes.
289 A zero value converted with precision zero yields no output.
290 o The argument from the argument stack is assumed to be of type unsigned
291 int, and is converted to an unsigned octal value, other behaviour being
293 u The argument from the argument stack is assumed to be of type unsigned
294 int, and converted to an unsigned decimal value, other behaviour being
296 x,X The argument from the argument stack is assumed to be of type unsigned
297 int, and converted to an unsigned hexadecimal value, using lowercase
298 "abcdef" for 'x' and uppercase "ABCDEF" for 'X' conversion, other
299 behaviour being as above.
300 f,F The argument from the argument stack is assumed to be of type double,
301 and converted to a decimal floating point in decimal-point notation,
302 with the number of digits after the decimal point as specified by the
303 precision (default 6) and the value being rounded appropriately. If
304 precision is zero (and the '#' flag is not given), no decimal point is
305 printed. At least one digit is always printed before the decimal point.
306 For 'f' conversions, an infinity value is printed as either [-]inf or
307 [-]infinity (, depending on the configuration of this implementation. A
308 NaN value is printed as [-]nan. For 'F' conversions uppercase characters
309 are used for these special values. The flags '-', '+' and ' ' apply as
310 usual to these special values, '#' and '0' have no effect.
311 e,E The argument from the argument stack is assumed to be of type double,
312 and converted to a decimal floating point in normalized exponential
313 notation ([?]d.ddd edd). "Normalized" means one nonzero digit before
314 the decimal point, unless the value is zero. The number of digits after
315 the decimal point is specified by the precision (default 6), the value
316 being rounded appropriately. If precision is zero (and the '#' flag is
317 not given), no decimal point is printed. The exponent has at least two
318 digits, and not more than necessary to represent the exponent. If the
319 value is zero, the exponent is zero. The 'e' written to indicate the
320 exponend is uppercase for 'E' conversions.
321 Infinity or NaN values are represented as for 'f' and 'F' conversions,
323 g,G The argument from the argument stack is assumed to be of type double,
324 and converted according to either 'f' or 'e' format for 'g' conversions,
325 or 'F' or 'E' format for 'G' conversions, respectively, with the actual
326 conversion chosen depending on the value. 'e' / 'E' conversion is chosen
327 if the resulting exponent is < -4 or >= the precision (default 1).
328 Trailing zeroes are removed (unless the '#' flag is given). A decimal
329 point appears only if followed by a digit.
330 Infinity or NaN values are represented as for 'f' and 'F' conversions,
332 a,A The argument from the argument stack is assumed to be of type double,
333 and converted to a floating point hexadecimal notation ([?]0xh.hhhh pd)
334 with one hexadecimal digit (being nonzero if the value is normalized,
335 and otherwise unspecified) before the decimal point, and the number of
336 digits after the decimal point being specified by the precision. If no
337 precision is given, the default is to print as many digits as nevessary
338 to give an exact representation of the value (if FLT_RADIX is a power of
339 2). If no precision is given and FLT_RADIX is not a power of 2, the
340 default is to print as many digits to distinguish values of type double
341 (possibly omitting trailing zeroes). (A precision p is sufficient to
342 distinguish values of the source type if 16^p-1 > b^n where b is
343 FLT_RADIX and n is the number of digits in the significand (to base b)
344 of the source type. A smaller p might suffice depending on the
345 implementation's scheme for determining the digit to the left of the
346 decimal point.) The error has the correct sign for the current rounding
348 Unless the '#' flag is given, no decimal-point is given for zero
350 The 'a' conversion uses lowercase "abcdef", "0x" and 'p', the 'A'
351 conversion uppercase "ABCDEF", "0X" and 'P'.
352 The exponent always has at least one digit, and not more than necessary
353 to represent the decimal exponent of 2. If the value is zero, the
355 Infinity or NaN values are represented as for 'f' and 'F' conversions,
357 Binary implementations are at liberty to chose the hexadecimal digit to
358 the left of the decimal point so that subsequent digits align to nibble
360 c The argument from the argument stack is assumed to be of type int, and
361 converted to a character after the value has been cast to unsigned char.
362 If the 'l' length modifier is given, the argument is assumed to be of
363 type wint_t, and converted as by a "%ls" conversion with no precision
364 and a pointer to a two-element wchar_t array, with the first element
365 being the wint_t argument and the second a '\0' wide character.
366 s The argument from the argument stack is assumed to be a char array (i.e.
367 pointer to char). Characters from that array are printed until a zero
368 byte is encountered or as many bytes as specified by a given precision
370 If the l length modifier is given, the argument from the argument stack
371 is assumed to be a wchar_t array (i.e. pointer to wchar_t). Wide
372 characters from that array are converted to multibyte characters as by
373 calls to wcrtomb() (using a mbstate_t object initialized to zero prior
374 to the first conversion), up to and including the terminating null wide
375 character. The resulting multibyte character sequence is then printed up
376 to but not including the terminating null character. If a precision is
377 given, it specifies the maximum number of bytes to be written (including
378 shift sequences). If the given precision would require access to a wide
379 character one past the end of the array, the array shall contain a '\0'
380 wide character. In no case is a partial multibyte character written.
381 Redundant shift sequences may result if the multibyte characters have a
382 state-dependent encoding.
383 TODO: Clarify these statements regarding %ls.
384 p The argument from the argument stack is assumed to be a void pointer,
385 and converted to a sequence of printing characters in an implementation-
387 This implementation casts the pointer to type intptr_t, and prints the
388 value as if a %#x conversion specifier was given.
389 n The argument from the argument stack is assumed to be a pointer to a
390 signed integer, into which the number of characters written so far by
391 this call to fprintf is stored. The behaviour, should any flags, field
392 widths, or precisions be given is undefined.
393 % A verbatim '%' character is written. No argument is taken from the
396 Returns the number of characters written if successful, a negative value
399 int fprintf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, ... );
401 /* TODO: fscanf() documentation */
403 Read input from a given stream, as defined by the given format string, and
404 store converted input in the objects pointed to by 0..n subsequent arguments
405 (the argument stack).
407 The format string contains a sequence of directives that are expected to
408 match the input. If such a directive fails to match, the function returns
409 (matching error). It also returns if an input error occurs (input error).
412 - one or more whitespaces, matching any number of whitespaces in the input;
413 - printing characters, matching the input verbatim;
414 - conversion specifications, which convert an input sequence into a value as
415 defined by the individual specifier, and store that value in a memory
416 location pointed to by the next pointer on the argument stack. Details are
417 documented below. If there is an insufficient number of pointers on the
418 argument stack, behaviour is undefined. Additional arguments not required
419 by any conversion specifications are evaluated, but otherwise ignored.
421 (The standard specifies the format string is allowed to contain multibyte
422 character sequences as long as it starts and ends in initial shift state,
423 but this is not yet supported by this implementation, which interprets the
424 format string as sequence of char.)
425 TODO: Add multibyte support to scanf() functions.
427 A conversion specifier consists of:
428 - Optional assignment-suppressing character ('*') that makes the conversion
429 read input as usual, but does not assign the conversion result.
430 - Optional maximum field width as decimal integer.
431 - Optional length modifier specifying the size of the argument (one of "hh",
432 "ll", or one of the characters "hljztL").
433 - Conversion specifier character specifying the type of conversion to be
434 applied (and the type of the next argument from the argument stack). One
435 of the characters "diouxXaAeEfFgGcs[pn%".
438 hh For "diouxXn" conversions, the next pointer from the argument stack is
439 assumed to point to a variable of of char width.
440 h For "diouxXn" conversions, the next pointer from the argument stack is
441 assumed to point to a variable of short int width.
442 l For "diouxXn" conversions, the next pointer from the argument stack is
443 assumed to point to a variable of long int width.
444 For "aAeEfFgG" conversions, it is assumed to point to a variable of type
446 For "cs[" conversions, it is assumed to point to a variable of type
448 ll For "diouxXn" conversions, the next pointer from the argument stack is
449 assumed to point to a variable of long long int width.
450 j For "diouxXn" conversions, the next pointer from the argument stack is
451 assumed to point to a variable of intmax_t width.
452 z For "diouxXn" conversions, the next pointer from the argument stack is
453 assumed to point to a variable of size_t width.
454 t For "diouxXn" conversions, the next pointer from the argument stack is
455 assumed to point to a variable of ptrdiff_t width.
456 L For "aAeEfFgG" conversions, the next pointer from the argument stack is
457 assumed to point to a variable of type long double.
458 Length modifiers appearing for any conversions not mentioned above will have
460 If a length modifier appears with any conversion specifier other than as
461 specified above, the behavior is undefined.
463 CONVERSION SPECIFIERS
464 d Matches an (optionally signed) decimal integer of the format expected
465 by strtol() with base 10. The next pointer from the argument stack is
466 assumed to point to a signed integer.
467 i Matches an (optionally signed) integer of the format expected by
468 strtol() with base 0. The next pointer from the argument stack is
469 assumed to point to a signed integer.
470 o Matches an (optionally signed) octal integer of the format expected by
471 strtoul() with base 8. The next pointer from the argument stack is
472 assumed to point to an unsigned integer.
473 u Matches an (optionally signed) decimal integer of the format expected
474 by strtoul() with base 10. The next pointer from the argument stack is
475 assumed to point to an unsigned integer.
476 x Matches an (optionally signed) hexadecimal integer of the format
477 expected by strtoul() with base 16. The next pointer from the argument
478 stack is assumed to point to an unsigned integer.
479 aefg Matches an (optionally signed) floating point number, infinity, or not-
480 a-number-value of the format expected by strtod(). The next pointer
481 from the argument stack is assumed to point to a float.
482 c Matches a number of characters as specified by the field width (default
483 1). The next pointer from the argument stack is assumed to point to a
484 character array large enough to hold that many characters.
485 If the 'l' length modifier is given, the input is assumed to match a
486 sequence of multibyte characters (starting in the initial shift state),
487 which will be converted to a wide character sequence as by successive
488 calls to mbrtowc() with a mbstate_t object initialized to zero prior to
489 the first conversion. The next pointer from the argument stack is
490 assumed to point to a wchar_t array large enough to hold that many
492 In either case, note that no '\0' character is added to terminate the
494 s Matches a sequence of non-white-space characters. The next pointer from
495 the argument stack is assumed to point to a character array large
496 enough to hold the sequence including terminating '\0' character.
497 If the 'l' length modifier is given, the input is assumed to match a
498 sequence of multibyte characters (starting in the initial shift state),
499 which will be converted to a wide character sequence as by a call to
500 mbrtowc() with a mbstate_t object initialized to zero prior to the
501 first conversion. The next pointer from the argument stack is assumed
502 to point to a wchar_t array large enough to hold the sequence including
503 terminating '\0' character.
504 [ Matches a nonempty sequence consisting of any of those characters
505 specified between itself and a corresponding closing bracket (']').
506 If the first character in the list is a circumflex ('^'), this matches
507 a nonempty sequence consisting of any characters NOT specified. If the
508 closing bracket appears as the first character in the scanset ("[]" or
509 "[^]", it is assumed to belong to the scanset, which then ends with the
510 NEXT closing bracket.
511 If there is a '-' character in the scanset which is not the first after
512 the opening bracket (or the circumflex, see above) or the last in the
513 scanset, behaviour is implementation-defined. This implementation
514 handles this character like any other.
516 The extend of the input field is determined byte-by-byte for the above
517 conversions ('c', 's', '['), with no special provisions being made for
518 multibyte characters. The resulting field is nevertheless a multibyte
519 sequence begining in intial shift state.
521 p Matches a sequence of characters as produced by the printf() "%p"
522 conversion. The next pointer from the argument stack is assumed to
523 point to a void pointer, which will be filled with the same location
524 as the pointer used in the printf() statement. Note that behaviour is
525 undefined if the input value is not the result of an earlier printf()
527 n Does not read input. The next pointer from the argument stack is
528 assumed to point to a signed integer, into which the number of
529 characters read from input so far by this call to fscanf() is stored.
530 This does not affect the return value of fscanf(). The behaviour,
531 should an assignment-supressing character of field width be given,
533 This can be used to test the success of literal matches and suppressed
535 % Matches a single, verbatim '%' character.
537 A, E, F, G and X are valid, and equivalent to their lowercase counterparts.
539 All conversions except [, c, or n imply that whitespace characters from the
540 input stream are consumed until a non-whitespace character is encountered.
541 Such whitespaces do not count against a maximum field width.
543 Conversions push at most one character back into the input stream. That
544 implies that some character sequences converted by the strtol() and strtod()
545 function families are not converted identically by the scnaf() function
548 Returns the number of input items successfully assigned. This can be zero if
549 an early mismatch occurs. Returns EOF if an input failure occurs before the
552 int fscanf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, ... );
554 /* Equivalent to fprintf( stdout, format, ... ). */
555 int printf( const char * _PDCLIB_restrict format, ... );
557 /* Equivalent to fscanf( stdin, format, ... ). */
558 int scanf( const char * _PDCLIB_restrict format, ... );
560 /* Equivalent to fprintf( stdout, format, ... ), except that the result is
561 written into the buffer pointed to by s, instead of stdout, and that any
562 characters beyond the (n-1)th are discarded. The (n)th character is
563 replaced by a '\0' character in this case.
564 Returns the number of characters that would have been written (not counting
565 the terminating '\0' character) if n had been sufficiently large, if
566 successful, and a negative number if an encoding error ocurred.
568 int snprintf( char * _PDCLIB_restrict s, size_t n, const char * _PDCLIB_restrict format, ... );
570 /* Equivalent to fprintf( stdout, format, ... ), except that the result is
571 written into the buffer pointed to by s, instead of stdout.
573 int sprintf( char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, ... );
575 /* Equivalent to fscanf( stdin, format, ... ), except that the input is read
576 from the buffer pointed to by s, instead of stdin.
578 int sscanf( const char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, ... );
580 /* Equivalent to fprintf( stream, format, ... ), except that the argument stack
581 is passed as va_list parameter. Note that va_list is not declared by
584 int vfprintf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
586 /* Equivalent to fscanf( stream, format, ... ), except that the argument stack
587 is passed as va_list parameter. Note that va_list is not declared by
590 int vfscanf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
592 /* Equivalent to fprintf( stdout, format, ... ), except that the argument stack
593 is passed as va_list parameter. Note that va_list is not declared by
596 int vprintf( const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
598 /* Equivalent to fscanf( stdin, format, ... ), except that the argument stack
599 is passed as va_list parameter. Note that va_list is not declared by
602 int vscanf( const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
604 /* Equivalent to snprintf( s, n, format, ... ), except that the argument stack
605 is passed as va_list parameter. Note that va_list is not declared by
608 int vsnprintf( char * _PDCLIB_restrict s, size_t n, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
610 /* Equivalent to fprintf( stdout, format, ... ), except that the argument stack
611 is passed as va_list parameter, and the result is written to the buffer
612 pointed to by s, instead of stdout. Note that va_list is not declared by
615 int vsprintf( char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
617 /* Equivalent to fscanf( stdin, format, ... ), except that the argument stack
618 is passed as va_list parameter, and the input is read from the buffer
619 pointed to by s, instead of stdin. Note that va_list is not declared by
622 int vsscanf( const char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
624 /* Character input/output functions */
626 /* Retrieve the next character from given stream.
627 Returns the character, EOF otherwise.
628 If end-of-file is reached, the EOF indicator of the stream is set.
629 If a read error occurs, the error indicator of the stream is set.
631 int fgetc( FILE * stream );
633 /* Read at most n-1 characters from given stream into the array s, stopping at
634 \n or EOF. Terminate the read string with \n. If EOF is encountered before
635 any characters are read, leave the contents of s unchanged.
636 Returns s if successful, NULL otherwise.
637 If a read error occurs, the error indicator of the stream is set. In this
638 case, the contents of s are indeterminate.
640 char * fgets( char * _PDCLIB_restrict s, int n, FILE * _PDCLIB_restrict stream );
642 /* Write the value c (cast to unsigned char) to the given stream.
643 Returns c if successful, EOF otherwise.
644 If a write error occurs, sets the error indicator of the stream is set.
646 int fputc( int c, FILE * stream );
648 /* Write the string s (not including the terminating \0) to the given stream.
649 Returns a value >=0 if successful, EOF otherwise.
650 This implementation does set the error indicator of the stream if a write
653 int fputs( const char * _PDCLIB_restrict s, FILE * _PDCLIB_restrict stream );
655 /* Equivalent to fgetc( stream ), but may be implemented as a macro that
656 evaluates its parameter more than once.
658 #define getc( stream ) fgetc( stream )
660 /* Equivalent to fgetc( stdin ), but may be implemented as a macro. */
661 #define getchar() fgetc( stdin )
663 /* Read characters from given stream into the array s, stopping at \n or EOF.
664 The string read is terminated with \0. Returns s if successful. If EOF is
665 encountered before any characters are read, the contents of s are unchanged,
666 and NULL is returned. If a read error occurs, the contents of s are indeter-
667 minate, and NULL is returned.
669 char * gets( char * s );
671 /* Equivalent to fputc( c, stream ), but may be implemented as a macro that
672 evaluates its parameter more than once.
674 #define putc( c, stream ) fputc( c, stream )
676 /* Equivalent to fputc( c, stdout ), but may be implemented as a macro that
677 evaluates its parameter more than once.
679 #define putchar( c ) putc( c, stdout )
681 /* Write the string s (not including the terminating \0) to stdout, and append
682 a newline to the output. Returns a value >= 0 when successful, EOF if a
683 write error occurred.
685 int puts( const char * s );
687 /* Push the value c (cast to unsigned char) back onto the given (input) stream.
688 A character pushed back in this way will be delivered by subsequent read
689 operations (and skipped by subsequent file positioning operations) as if it
690 has not been read. The external representation of the stream is unaffected
691 by this pushback (it is a buffer operation). One character of pushback is
692 guaranteed, further pushbacks may fail. EOF as value for c does not change
693 the input stream and results in failure of the function.
694 For text files, the file position indicator is indeterminate until all
695 pushed-back characters are read. For binary files, the file position
696 indicator is decremented by each successful call of ungetc(). If the file
697 position indicator for a binary file was zero before the call of ungetc(),
698 behaviour is undefined. (Older versions of the library allowed such a call.)
699 Returns the pushed-back character if successful, EOF if it fails.
701 int ungetc( int c, FILE * stream );
703 /* Direct input/output functions */
705 /* Read up to nmemb elements of given size from given stream into the buffer
706 pointed to by ptr. Returns the number of elements successfully read, which
707 may be less than nmemb if a read error or EOF is encountered. If a read
708 error is encountered, the value of the file position indicator is
709 indeterminate. If a partial element is read, its value is indeterminate.
710 If size or nmemb are zero, the function does nothing and returns zero.
712 size_t fread( void * _PDCLIB_restrict ptr, size_t size, size_t nmemb, FILE * _PDCLIB_restrict stream );
714 /* Write up to nmemb elements of given size from buffer pointed to by ptr to
715 the given stream. Returns the number of elements successfully written, which
716 will be less than nmemb only if a write error is encountered. If a write
717 error is encountered, the value of the file position indicator is
718 indeterminate. If size or nmemb are zero, the function does nothing and
721 size_t fwrite( const void * _PDCLIB_restrict ptr, size_t size, size_t nmemb, FILE * _PDCLIB_restrict stream );
723 /* File positioning functions */
725 /* Store the current position indicator (and, where appropriate, the current
726 mbstate_t status object) for the given stream into the given pos object. The
727 actual contents of the object are unspecified, but it can be used as second
728 parameter to fsetpos() to reposition the stream to the exact position and
729 parse state at the time fgetpos() was called.
730 Returns zero if successful, nonzero otherwise.
731 TODO: Implementation-defined errno setting for fgetpos().
733 int fgetpos( FILE * _PDCLIB_restrict stream, fpos_t * _PDCLIB_restrict pos );
735 /* Set the position indicator for the given stream to the given offset from:
736 - the beginning of the file if whence is SEEK_SET,
737 - the current value of the position indicator if whence is SEEK_CUR,
738 - end-of-file if whence is SEEK_END.
739 On text streams, non-zero offsets are only allowed with SEEK_SET, and must
740 have been returned by ftell() for the same file.
741 Any characters buffered by ungetc() are dropped, the end-of-file indicator
742 for the stream is cleared. If the given stream is an update stream, the next
743 operation after a successful fseek() may be either input or output.
744 Returns zero if successful, nonzero otherwise. If a read/write error occurs,
745 the error indicator for the given stream is set.
747 int fseek( FILE * stream, long int offset, int whence );
749 /* Set the position indicator (and, where appropriate the mbstate_t status
750 object) for the given stream to the given pos object (created by an earlier
751 call to fgetpos() on the same file).
752 Any characters buffered by ungetc() are dropped, the end-of-file indicator
753 for the stream is cleared. If the given stream is an update stream, the next
754 operation after a successful fsetpos() may be either input or output.
755 Returns zero if successful, nonzero otherwise. If a read/write error occurs,
756 the error indicator for the given stream is set.
757 TODO: Implementation-defined errno setting for fsetpos().
759 int fsetpos( FILE * stream, const fpos_t * pos );
761 /* Return the current offset of the given stream from the beginning of the
762 associated file. For text streams, the exact value returned is unspecified
763 (and may not be equal to the number of characters), but may be used in
764 subsequent calls to fseek().
765 Returns -1L if unsuccessful.
766 TODO: Implementation-defined errno setting for ftell().
768 long int ftell( FILE * stream );
770 /* Equivalent to (void)fseek( stream, 0L, SEEK_SET ), except that the error
771 indicator for the stream is also cleared.
773 void rewind( FILE * stream );
775 /* Error-handling functions */
777 /* Clear the end-of-file and error indicators for the given stream. */
778 void clearerr( FILE * stream );
780 /* Return zero if the end-of-file indicator for the given stream is not set,
783 int feof( FILE * stream );
785 /* Return zero if the error indicator for the given stream is not set, nonzero
788 int ferror( FILE * stream );
790 /* If s is neither a NULL pointer nor an empty string, print the string to
791 stderr (with appended colon (':') and a space) first. In any case, print an
792 error message depending on the current value of errno (being the same as if
793 strerror( errno ) had been called).
795 void perror( const char * s );