--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <ctype.h>
+#include <assert.h>
+#include <string.h>
+
+#undef TEST
+#include </home/solar/src/pdclib/functions/_PDCLIB/digits.c>
+
+/* Using an integer's bits as flags for both the conversion flags and length
+ modifiers.
+*/
+#define E_minus 1<<0
+#define E_plus 1<<1
+#define E_alt 1<<2
+#define E_space 1<<3
+#define E_zero 1<<4
+#define E_done 1<<5
+#define E_char 1<<6
+#define E_short 1<<7
+#define E_long 1<<8
+#define E_llong 1<<9
+#define E_intmax 1<<10
+#define E_size 1<<11
+#define E_ptrdiff 1<<12
+#define E_double 1<<13
+#define E_lower 1<<14
+#define E_term 1<<15
+
+void parse_out( const char * spec, va_list ap );
+
+struct status_t
+{
+ int base; /* base to which the value shall be converted */
+ int flags; /* flags and length modifiers */
+ size_t n; /* maximum number of characters to be written */
+ size_t i; /* number of characters already written */
+ size_t this; /* number of output chars in the current conversion */
+ char * s; /* target buffer */
+ size_t width; /* width of current field */
+ int prec; /* precision of current field */
+};
+
+/* x - the character to be delivered
+ i - pointer to number of characters already delivered in this call
+ n - pointer to maximum number of characters to be delivered in this call
+ s - the buffer into which the character shall be delivered
+ TODO: Overruns.
+*/
+#define DELIVER( x ) if ( status->i < status->n ) status->s[status->i] = x; ++(status->i)
+
+/* TODO: Left / right alignment - requires track-keeping of width and printed chars.
+ "Father function", die für right alignment "tail recursive" gerufen wird, und
+ "after" für left alignment? Parameter als struct?
+*/
+
+static void int2base( int value, struct status_t * status )
+{
+ ++(status->this);
+ if ( ( value / status->base ) != 0 )
+ {
+ int2base( value / status->base, status );
+ }
+ else
+ {
+ char preface[3] = "\0\0";
+ size_t preidx = 0;
+ if ( ( status->flags & E_alt ) && ( status->base == 16 || status->base == 8 ) )
+ {
+ preface[ preidx++ ] = '0';
+ if ( status->base == 16 )
+ {
+ preface[ preidx++ ] = ( status->flags & E_lower ) ? 'x' : 'X';
+ }
+ }
+ if ( value < 0 )
+ {
+ preface[ preidx++ ] = '-';
+ }
+ else
+ {
+ if ( status->flags & E_plus )
+ {
+ preface[ preidx++ ] = '+';
+ }
+ else if ( status->flags & E_space )
+ {
+ preface[ preidx++ ] = ' ';
+ }
+ }
+ if ( ! ( ( status->flags & E_minus ) || ( status->flags & E_zero ) ) )
+ {
+ while ( ( status->this + preidx ) < status->width )
+ {
+ DELIVER( ' ' );
+ ++(status->this);
+ }
+ }
+ preidx = 0;
+ while ( preface[ preidx ] != '\0' )
+ {
+ DELIVER( preface[ preidx++ ] );
+ ++(status->this);
+ }
+ if ( ( ! ( status->flags & E_minus ) ) && ( status->flags & E_zero ) )
+ {
+ while ( status->this < status->width )
+ {
+ DELIVER( '0' );
+ ++(status->this);
+ }
+ }
+ }
+ if ( value < 0 )
+ {
+ value *= -1;
+ }
+ if ( status->flags & E_lower )
+ {
+ DELIVER( _PDCLIB_digits[ value % status->base ] );
+ }
+ else
+ {
+ DELIVER( toupper( _PDCLIB_digits[ value % status->base ] ) );
+ }
+}
+
+static void padwrap( int value, struct status_t * status )
+{
+ int2base( value, status );
+ if ( status->flags & E_minus )
+ {
+ while ( status->this < status->width )
+ {
+ DELIVER( ' ' );
+ ++(status->this);
+ }
+ }
+ if ( status->i == status->n )
+ {
+ status->s[status->i] = '\0';
+ }
+}
+
+void parse_out( const char * spec, va_list ap )
+{
+ /* TODO: '%' handled correctly? */
+ struct status_t status = { 0, 0, 0, 0, 0, NULL, 0, EOF };
+ /* First come 0..n flags */
+ while ( ! ( status.flags & E_done ) )
+ {
+ switch ( *(++spec) )
+ {
+ case '-':
+ status.flags |= E_minus;
+ break;
+ case '+':
+ status.flags |= E_plus;
+ break;
+ case '#':
+ status.flags |= E_alt;
+ break;
+ case ' ':
+ status.flags |= E_space;
+ break;
+ case '0':
+ status.flags |= E_zero;
+ break;
+ default:
+ status.flags |= E_done;
+ break;
+ }
+ }
+ if ( *spec == '*' )
+ {
+ /* Retrieve width value from argument stack */
+ if ( ( status.width = va_arg( ap, int ) ) < 0 )
+ {
+ /* Negative value is '-' flag plus absolute value */
+ status.flags |= E_minus;
+ status.width *= -1;
+ }
+ ++spec;
+ }
+ else
+ {
+ /* If a width is given, strtol() will return its value. If not given,
+ strtol() will return zero. In both cases, endptr will point to the
+ rest of the conversion specifier.
+ */
+ char * endptr;
+ status.width = (int)strtol( spec, &endptr, 10 );
+ spec = endptr;
+ }
+ if ( *spec == '.' )
+ {
+ if ( *(++spec) == '*' )
+ {
+ /* Retrieve precision value from argument stack. A negative value
+ is as if no precision is given - as precision is initalized to
+ EOF (negative), there is no need for testing for negative here.
+ */
+ status.prec = va_arg( ap, int );
+ }
+ else
+ {
+ char * endptr;
+ status.prec = (int)strtol( spec, &endptr, 10 );
+ spec = endptr;
+ }
+ }
+ /* We step one character ahead in any case, and step back only if we find
+ there has been no length modifier (or step ahead another character if it
+ has been "hh" or "ll").
+ */
+ switch ( *(spec++) )
+ {
+ case 'h':
+ if ( *spec == 'h' )
+ {
+ status.flags |= E_char;
+ ++spec;
+ }
+ else
+ {
+ status.flags |= E_short;
+ }
+ break;
+ case 'l':
+ if ( *spec == 'l' )
+ {
+ status.flags |= E_llong;
+ ++spec;
+ }
+ else
+ {
+ status.flags |= E_long;
+ }
+ break;
+ case 'j':
+ status.flags |= E_intmax;
+ break;
+ case 'z':
+ status.flags |= E_size;
+ break;
+ case 't':
+ status.flags |= E_ptrdiff;
+ break;
+ case 'L':
+ status.flags |= E_double;
+ break;
+ default:
+ ++spec;
+ break;
+ }
+ switch ( *spec )
+ {
+ case 'd':
+ case 'i':
+ /* int2base( 10, value, true ) */
+ break;
+ case 'o':
+ /* int2base( 8, value, true ) */
+ break;
+ case 'u':
+ /* uint2base( 10, value, true ) */
+ break;
+ case 'x':
+ /* uint2base( 16, value, true ) */
+ break;
+ case 'X':
+ /* uint2base( 16, value, false ) */
+ break;
+ case 'f':
+ case 'F':
+ case 'e':
+ case 'E':
+ case 'g':
+ case 'G':
+ break;
+ case 'a':
+ case 'A':
+ break;
+ case 'c':
+ break;
+ case 's':
+ break;
+ case 'p':
+ /* uint2base( 16, (intptr_t)value, true ) */
+ case 'n':
+ case '%':
+ // conversion specifier
+ break;
+ default:
+ // undefined
+ return;
+ }
+}
+
+/*
+static void int2base( int value, int base, struct status_t * status )
+
+#define E_minus 1<<0
+#define E_plus 1<<1
+#define E_alt 1<<2
+#define E_space 1<<3
+#define E_zero 1<<4
+#define E_done 1<<5
+#define E_char 1<<6
+#define E_short 1<<7
+#define E_long 1<<8
+#define E_llong 1<<9
+#define E_intmax 1<<10
+#define E_size 1<<11
+#define E_ptrdiff 1<<12
+#define E_double 1<<13
+#define E_lower 1<<14
+
+ struct status_t
+{
+ int flags;
+ size_t n;
+ size_t i;
+ char * s;
+ size_t width;
+ size_t prec;
+};
+*/
+
+#define TESTCASE( _flags, _n, _width, _prec, _value, _base, _expect ) \
+ status.flags = _flags | E_term; \
+ status.n = _n; \
+ status.i = 0; \
+ status.width = _width; \
+ status.prec = _prec; \
+ status.base = _base; \
+ status.this = 0; \
+ memset( status.s, '\0', 20 ); \
+ padwrap( _value, &status ); \
+ printf( "Output '%s', RC %d \t- ", status.s, status.i ); \
+ rc = snprintf( buffer, _n, _expect, _value ); \
+ printf( "Expect '%s', RC %d\n", buffer, rc );
+
+int main()
+{
+ struct status_t status;
+ int rc;
+ char * buffer = malloc( 20 );
+ status.s = malloc( 20 );
+ TESTCASE( E_plus, 5, 0, 0, 1234, 10, "%+d" );
+ TESTCASE( E_space, 3, 0, 0, 1234, 10, "% d" );
+ TESTCASE( E_space, 3, 0, 0, -1234, 10, "% d" );
+ TESTCASE( E_plus, 3, 0, 0, -1234, 10, "%+d" );
+ TESTCASE( E_done, 4, 0, 0, 65535, 16, "%X" );
+ TESTCASE( E_lower | E_alt, 4, 0, 0, 65534, 16, "%#x" );
+ TESTCASE( E_done, 4, 0, 0, 62, 8, "%o" );
+ TESTCASE( E_alt, 4, 0, 0, 62, 8, "%#o" );
+ TESTCASE( E_done, 6, 6, 0, 1234, 10, "%6d" );
+ TESTCASE( E_minus, 6, 6, 0, 1234, 10, "%-6d" );
+ TESTCASE( E_minus, 6, 2, 0, 1234, 10, "%-2d" );
+ TESTCASE( E_done, 6, 2, 0, 1234, 10, "%2d" );
+ TESTCASE( E_zero, 6, 6, 0, -1234, 10, "%06d" );
+ TESTCASE( E_zero, 7, 7, 0, -65535, 16, "%07X" );
+ TESTCASE( E_zero | E_minus, 6, 6, 0, 1234, 10, "%-06d" );
+ TESTCASE( E_plus, 6, 6, 0, 1234, 10, "%+6d" );
+ TESTCASE( E_space, 6, 6, 0, 1234, 10, "% 6d" );
+ TESTCASE( E_space, 6, 6, 0, -1234, 10, "% 6d" );
+ TESTCASE( E_space | E_minus, 6, 6, 0, -1234, 10, "%- 6d" );
+ return 0;
+}
int setvbuf( FILE * _PDCLIB_restrict stream, char * _PDCLIB_restrict buf, int mode, size_t size );
/* Formatted input/output functions */
+
+/*
+ Write output to the given stream, as defined by the given format string and
+ 0..n subsequent arguments (the argument stack).
+
+ The format string is written to the given stream verbatim, except for any
+ conversion specifiers included, which start with the letter '%' and are
+ documented below. If the given conversion specifiers require more arguments
+ from the argument stack than provided, behaviour is undefined. Additional
+ arguments not required by conversion specifiers are evaluated but otherwise
+ ignored.
+
+ (The standard specifies the format string is allowed to contain multibyte
+ character sequences as long as it starts and ends in initial shift state,
+ but this is not yet supported by this implementation, which interprets the
+ format string as sequence of char.)
+ TODO: Add multibyte support to printf() functions.
+
+ A conversion specifier consists of:
+ - Zero or more flags (one of the characters "-+ #0").
+ - Optional minimum field width as decimal integer. Default is padding to the
+ left, using spaces. Note that 0 is taken as a flag, not the beginning of a
+ field width. Note also that a small field width will not result in the
+ truncation of a value.
+ - Optional precision (given as ".#" with # being a decimal integer),
+ specifying:
+ - the min. number of digits to appear (diouxX),
+ - the max. number of digits after the decimal point (aAeEfF),
+ - the max. number of significant digits (gG),
+ - the max. number of bytes to be written (s).
+ - behaviour with other conversion specifiers is undefined.
+ - Optional length modifier specifying the size of the argument (one of "hh",
+ "ll", or one of the characters "hljztL").
+ - Conversion specifier character specifying the type of conversion to be
+ applied (and the type of the next argument from the argument stack). One
+ of the characters "diouxXfFeEgGaAcspn%".
+
+ Minimum field width and/or precision may be given as asterisk ('*') instead
+ of a decimal integer. In this case, the next argument from the argument
+ stack is assumed to be an int value specifying the width / precision. A
+ negative field width is interpreted as flag '-' followed by a positive field
+ width. A negative precision is interpreted as if no precision was given.
+
+ FLAGS
+ - Left-justify the conversion result within its field width.
+ + Prefix a '+' on positive signed conversion results. Prefix a '-' on
+ floating conversions resulting in negative zero, or negative values
+ rounding to zero.
+ space Prefix a space on positive signed conversion results, or if a signed
+ conversion results in no characters. If both '+' and ' ' are given,
+ ' ' is ignored.
+ # Use an "alternative form" for
+ - 'o' conversion, increasing precision until the first digit of the
+ result is a zero;
+ - 'x' or 'X' conversion, prefixing "0x" or "0X" to nonzero results;
+ - "aAeEfF" conversions, always printing a decimal point even if no
+ digits are following;
+ - 'g' or 'G' conversions, always printing a decimal point even if no
+ digits are following, and not removing trailing zeroes.
+ - behaviour for other conversions is unspecified.
+ 0 Use leading zeroes instead of spaces for field width padding. If both
+ '-' and '0' are given, '0' is ignored. If a precision is specified for
+ any of the "diouxX" conversions, '0' is ignored. Behaviour is only
+ defined for "diouxXaAeEfFgG".
+
+ LENGTH MODIFIERS
+ hh For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of char width. (It will have been subject to integer
+ promotion but will be converted back.) For 'n' conversions, the argument
+ is assumed to be a pointer to signed char.
+ h For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of short int width. (It will have been subject to integer
+ promotion but will be converted back.) For 'n' conversions, the argument
+ is assumed to be a pointer to short int.
+ l For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of long int width. For 'n' conversions, the argument is
+ assumed to be a pointer to short int. For 'c' conversions, the argument
+ is assumed to be a wint_t. For 's' conversions, the argument is assumed
+ to be a pointer to wchar_t. No effect on "aAeEfFgG" conversions.
+ ll For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of long long int width. For 'n' conversions, the argument
+ is assumed to be a pointer to long long int.
+ j For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of intmax_t width. For 'n' conversions, the argument is
+ assumed to be a pointer to intmax_t.
+ z For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of size_t width. For 'n' conversions, the argument is
+ assumed to be a pointer to size_t.
+ t For "diouxX" conversions, the argument from the argument stack is
+ assumed to be of ptrdiff_t width. For 'n' conversions, the argument is
+ assumed to be a pointer to ptrdiff_t.
+ L For "aAeEfFgG" conversions, the argument from the argument stack is
+ assumed to be a long double.
+ Length modifiers appearing for any conversions not mentioned above will have
+ undefined behaviour.
+ If a length modifier appears with any conversion specifier other than as
+ specified above, the behavior is undefined.
+
+ CONVERSION SPECIFIERS
+ d,i The argument from the argument stack is assumed to be of type int, and
+ is converted to a signed decimal value with a minimum number of digits
+ as specified by the precision (default 1), padded with leading zeroes.
+ A zero value converted with precision zero yields no output.
+ o The argument from the argument stack is assumed to be of type unsigned
+ int, and is converted to an unsigned octal value, other behaviour being
+ as above.
+ u The argument from the argument stack is assumed to be of type unsigned
+ int, and converted to an unsigned decimal value, other behaviour being
+ as above.
+ x,X The argument from the argument stack is assumed to be of type unsigned
+ int, and converted to an unsigned hexadecimal value, using lowercase
+ "abcdef" for 'x' and uppercase "ABCDEF" for 'X' conversion, other
+ behaviour being as above.
+ f,F The argument from the argument stack is assumed to be of type double,
+ and converted to a decimal floating point in decimal-point notation,
+ with the number of digits after the decimal point as specified by the
+ precision (default 6) and the value being rounded appropriately. If
+ precision is zero (and the '#' flag is not given), no decimal point is
+ printed. At least one digit is always printed before the decimal point.
+ For 'f' conversions, an infinity value is printed as either [-]inf or
+ [-]infinity (, depending on the configuration of this implementation. A
+ NaN value is printed as [-]nan. For 'F' conversions uppercase characters
+ are used for these special values. The flags '-', '+' and ' ' apply as
+ usual to these special values, '#' and '0' have no effect.
+ e,E The argument from the argument stack is assumed to be of type double,
+ and converted to a decimal floating point in normalized exponential
+ notation ([?]d.ddd e±dd). "Normalized" means one nonzero digit before
+ the decimal point, unless the value is zero. The number of digits after
+ the decimal point is specified by the precision (default 6), the value
+ being rounded appropriately. If precision is zero (and the '#' flag is
+ not given), no decimal point is printed. The exponent has at least two
+ digits, and not more than necessary to represent the exponent. If the
+ value is zero, the exponent is zero. The 'e' written to indicate the
+ exponend is uppercase for 'E' conversions.
+ Infinity or NaN values are represented as for 'f' and 'F' conversions,
+ respectively.
+ g,G The argument from the argument stack is assumed to be of type double,
+ and converted according to either 'f' or 'e' format for 'g' conversions,
+ or 'F' or 'E' format for 'G' conversions, respectively, with the actual
+ conversion chosen depending on the value. 'e' / 'E' conversion is chosen
+ if the resulting exponent is < -4 or >= the precision (default 1).
+ Trailing zeroes are removed (unless the '#' flag is given). A decimal
+ point appears only if followed by a digit.
+ Infinity or NaN values are represented as for 'f' and 'F' conversions,
+ respectively.
+ a,A The argument from the argument stack is assumed to be of type double,
+ and converted to a floating point hexadecimal notation ([?]0xh.hhhh p±d)
+ with one hexadecimal digit (being nonzero if the value is normalized,
+ and otherwise unspecified) before the decimal point, and the number of
+ digits after the decimal point being specified by the precision. If no
+ precision is given, the default is to print as many digits as nevessary
+ to give an exact representation of the value (if FLT_RADIX is a power of
+ 2). If no precision is given and FLT_RADIX is not a power of 2, the
+ default is to print as many digits to distinguish values of type double
+ (possibly omitting trailing zeroes). (A precision p is sufficient to
+ distinguish values of the source type if 16^p-1 > b^n where b is
+ FLT_RADIX and n is the number of digits in the significand (to base b)
+ of the source type. A smaller p might suffice depending on the
+ implementation's scheme for determining the digit to the left of the
+ decimal point.) The error has the correct sign for the current rounding
+ direction.
+ Unless the '#' flag is given, no decimal-point is given for zero
+ precision.
+ The 'a' conversion uses lowercase "abcdef", "0x" and 'p', the 'A'
+ conversion uppercase "ABCDEF", "0X" and 'P'.
+ The exponent always has at least one digit, and not more than necessary
+ to represent the decimal exponent of 2. If the value is zero, the
+ exponent is zero.
+ Infinity or NaN values are represented as for 'f' and 'F' conversions,
+ respectively.
+ Binary implementations are at liberty to chose the hexadecimal digit to
+ the left of the decimal point so that subsequent digits align to nibble
+ boundaries.
+ c The argument from the argument stack is assumed to be of type int, and
+ converted to a character after the value has been cast to unsigned char.
+ If the 'l' length modifier is given, the argument is assumed to be of
+ type wint_t, and converted as by a "%ls" conversion with no precision
+ and a pointer to a two-element wchar_t array, with the first element
+ being the wint_t argument and the second a '\0' wide character.
+ s The argument from the argument stack is assumed to be a char array (i.e.
+ pointer to char). Characters from that array are printed until a zero
+ byte is encountered or as many bytes as specified by a given precision
+ have been written.
+ If the l length modifier is given, the argument from the argument stack
+ is assumed to be a wchar_t array (i.e. pointer to wchar_t). Wide
+ characters from that array are converted to multibyte characters as by
+ calls to wcrtomb() (using a mbstate_t object initialized to zero prior
+ to the first conversion), up to and including the terminating null wide
+ character. The resulting multibyte character sequence is then printed up
+ to but not including the terminating null character. If a precision is
+ given, it specifies the maximum number of bytes to be written (including
+ shift sequences). If the given precision would require access to a wide
+ character one past the end of the array, the array shall contain a '\0'
+ wide character. In no case is a partial multibyte character written.
+ Redundant shift sequences may result if the multibyte characters have a
+ state-dependent encoding.
+ TODO: Clarify these statements regarding %ls.
+ p The argument from the argument stack is assumed to be a void pointer,
+ and converted to a sequence of printing characters in an implementation-
+ defined manner.
+ This implementation casts the pointer to type intptr_t, and prints the
+ value as if a %#x conversion specifier was given.
+ n The argument from the argument stack is assumed to be a pointer to a
+ signed integer, into which the number of characters written so far by
+ this call to fprintf is stored. The behaviour, should any flags, field
+ widths, or precisions be given is undefined.
+ % A verbatim '%' character is written. No argument is taken from the
+ argument stack.
+
+ Returns the number of characters written if successful, a negative value
+ otherwise.
+*/
int fprintf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, ... );
+
+/* TODO: fscanf() documentation */
+/*
+ Write output to the given stream, as defined by the given format string and
+ 0..n subsequent arguments (the argument stack).
+
+ The format string is written to the given stream verbatim, except for any
+ conversion specifiers included, which start with the letter '%' and are
+ documented below. If the given conversion specifiers require more arguments
+ from the argument stack than provided, behaviour is undefined. Additional
+ arguments not required by conversion specifiers are evaluated but otherwise
+ ignored.
+
+ (The standard specifies the format string is allowed to contain multibyte
+ character sequences as long as it starts and ends in initial shift state,
+ but this is not yet supported by this implementation, which interprets the
+ format string as sequence of char.)
+ TODO: Add multibyte support to printf() functions.
+
+ Read input from the given stream, as defined by the given format string and
+ 0..n subsequent arguments (the argument stack).
+
+ The format string contains a sequence of directives that are expected to
+ match the input. If such a directive fails to match, the function returns
+ (matching error). It also returns if an input error occurs (input error).
+
+ Directives can be:
+ - one or more whitespaces, matching any number of whitespaces in the input;
+ - printing characters, matching the input verbatim;
+ - conversion specifications, which convert an input sequence into a value as
+ defined by the individual specifier, and store that value in a memory
+ location pointed to by the next pointer on the argument stack. Details are
+ documented below. If there is an insufficient number of pointers on the
+ argument stack, behaviour is undefined. Additional arguments not required
+ by any conversion specifications are evaluated, but otherwise ignored.
+
+The format shall be a multibyte character sequence, beginning and ending in its initial
+shift state. The format is composed of zero or more directives: one or more white-space
+characters, an ordinary multibyte character (neither % nor a white-space character), or a
+conversion speci?cation. Each conversion speci?cation is introduced by the character %.
+After the %, the following appear in sequence:
+? An optional assignment-suppressing character *.
+? An optional nonzero decimal integer that speci?es the maximum ?eld width (in
+ characters).
+? An optional length modi?er that speci?es the size of the receiving object.
+? A conversion speci?er character that speci?es the type of conversion to be applied.
+The fscanf function executes each directive of the format in turn. If a directive fails, as
+detailed below, the function returns. Failures are described as input failures (due to the
+occurrence of an encoding error or the unavailability of input characters), or matching
+failures (due to inappropriate input).
+A directive composed of white-space character(s) is executed by reading input up to the
+?rst non-white-space character (which remains unread), or until no more characters can
+be read.
+A directive that is an ordinary multibyte character is executed by reading the next
+characters of the stream. If any of those characters differ from the ones composing the
+directive, the directive fails and the differing and subsequent characters remain unread.
+Similarly, if end-of-?le, an encoding error, or a read error prevents a character from being
+read, the directive fails.
+A directive that is a conversion speci?cation de?nes a set of matching input sequences, as
+described below for each speci?er. A conversion speci?cation is executed in the
+following steps:
+Input white-space characters (as speci?ed by the isspace function) are skipped, unless
+the speci?cation includes a [, c, or n speci?er.241)
+These white-space characters are not counted against a speci?ed ?eld width.
+An input item is read from the stream, unless the speci?cation includes an n speci?er. An
+input item is de?ned as the longest sequence of input characters which does not exceed
+any speci?ed ?eld width and which is, or is a pre?x of, a matching input sequence.242)
+fscanf pushes back at most one input character onto the input stream. Therefore, some sequences
+that are acceptable to strtod, strtol, etc., are unacceptable to fscanf.
+The ?rst character, if any, after the input item remains unread. If the length of the input
+item is zero, the execution of the directive fails; this condition is a matching failure unless
+end-of-?le, an encoding error, or a read error prevented input from the stream, in which
+case it is an input failure.
+Except in the case of a % speci?er, the input item (or, in the case of a %n directive, the
+count of input characters) is converted to a type appropriate to the conversion speci?er. If
+the input item is not a matching sequence, the execution of the directive fails: this
+condition is a matching failure. Unless assignment suppression was indicated by a *, the
+result of the conversion is placed in the object pointed to by the ?rst argument following
+the format argument that has not already received a conversion result. If this object
+does not have an appropriate type, or if the result of the conversion cannot be represented
+in the object, the behavior is unde?ned.
+The length modi?ers and their meanings are:
+
+ LENGTH MODIFIERS
+ hh For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of of char width.
+ h For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of short int width.
+ l For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of long int width.
+ For "aAeEfFgG" conversions, it is assumed to point to a variable of type
+ double.
+ For "cs[" conversions, it is assumed to point to a variable of type
+ wchar_t.
+ ll For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of long long int width.
+ j For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of intmax_t width.
+ z For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of size_t width.
+ t For "diouxXn" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of ptrdiff_t width.
+ L For "aAeEfFgG" conversions, the next pointer from the argument stack is
+ assumed to point to a variable of type long double.
+ Length modifiers appearing for any conversions not mentioned above will have
+ undefined behaviour.
+ If a length modifier appears with any conversion specifier other than as
+ specified above, the behavior is undefined.
+
+ CONVERSION SPECIFIERS
+ d Matches an (optionally signed) decimal integer of the format expected
+ by strtol() with base 10. The next pointer from the argument stack is
+ assumed to point to a signed integer.
+ i Matches an (optionally signed) integer of the format expected by
+ strtol() with base 0. The next pointer from the argument stack is
+ assumed to point to a signed integer.
+ o Matches an (optionally signed) octal integer of the format expected by
+ strtoul() with base 8. The next pointer from the argument stack is
+ assumed to point to an unsigned integer.
+ u Matches an (optionally signed) decimal integer of the format expected
+ by strtoul() with base 10. The next pointer from the argument stack is
+ assumed to point to an unsigned integer.
+ x Matches an (optionally signed) hexadecimal integer of the format
+ expected by strtoul() with base 16. The next pointer from the argument
+ stack is assumed to point to an unsigned integer.
+ aefg Matches an (optionally signed) floating point number, infinity, or not-
+ a-number-value of the format expected by strtod(). The next pointer
+ from the argument stack is assumed to point to a float.
+ c Matches a number of characters as specified by the field width (default
+ 1). The next pointer from the argument stack is assumed to point to a
+ character array large enough to hold that many characters.
+ If the 'l' length modifier is given, the input is assumed to match a
+ sequence of multibyte characters (starting in the initial shift state),
+ which will be converted to a wide character sequence as by successive
+ calls to mbrtowc() with a mbstate_t object initialized to zero prior to
+ the first conversion. The next pointer from the argument stack is
+ assumed to point to a wchar_t array large enough to hold that many
+ characters.
+ In either case, note that no '\0' character is added to terminate the
+ sequence.
+ s Matches a sequence of non-white-space characters. The next pointer from
+ the argument stack is assumed to point to a character array large
+ enough to hold the sequence including terminating '\0' character.
+ If the 'l' length modifier is given, the input is assumed to match a
+ sequence of multibyte characters (starting in the initial shift state),
+ which will be converted to a wide character sequence as by a call to
+ mbrtowc() with a mbstate_t object initialized to zero prior to the
+ first conversion. The next pointer from the argument stack is assumed
+ to point to a wchar_t array large enough to hold the sequence including
+ terminating '\0' character.
+ [ Matches a nonempty sequence consisting of any of those characters
+ specified between itself and a corresponding closing bracket (']').
+ If the first character in the list is a circumflex ('^'), this matches
+ a nonempty sequence consisting of any characters NOT specified. If the
+ closing bracket appears as the first character in the scanset ("[]" or
+ "[^]", it is assumed to belong to the scanset, which then ends with the
+ NEXT closing bracket.
+ If there is a '-' character in the scanset which is not the first after
+ the opening bracket (or the circumflex, see above) or the last in the
+ scanset, behaviour is implementation-defined. This implementation
+ handles this character like any other.
+
+ The extend of the input field is determined byte-by-byte for the above
+ conversions ('c', 's', '['), with no special provisions being made for
+ multibyte characters. The resulting field is nevertheless a multibyte
+ sequence begining in intial shift state.
+
+ p Matches a sequence of characters as produced by the printf() "%p"
+ conversion. The next pointer from the argument stack is assumed to
+ point to a void pointer, which will be filled with the same location
+ as the pointer used in the printf() statement. Note that behaviour is
+ undefined if the input value is not the result of an earlier printf()
+ call.
+ n Does not read input. The next pointer from the argument stack is
+ assumed to point to a signed integer, into which the number of
+ characters read from input so far by this call to fscanf() is stored.
+ This does not affect the return value of fscanf(). The behaviour,
+ should an assignment-supressing character of field width be given,
+ is undefined.
+ This can be used to test the success of literal matches and suppressed
+ assignments.
+ % Matches a single, verbatim '%' character.
+
+ A, E, F, G and X are valid, and equivalent to their lowercase counterparts.
+
+ Returns the number of input items successfully assigned. This can be zero if
+ an early mismatch occurs. Returns EOF if an input failure occurs before the
+ first conversion.
+*/
int fscanf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, ... );
+
+/* Equivalent to fprintf( stdout, format, ... ). */
int printf( const char * _PDCLIB_restrict format, ... );
+
+/* Equivalent to fscanf( stdin, format, ... ). */
int scanf( const char * _PDCLIB_restrict format, ... );
+
+/* Equivalent to fprintf( stdout, format, ... ), except that the result is
+ written into the buffer pointed to by s, instead of stdout, and that any
+ characters beyond the (n-1)th are discarded. The (n)th character is
+ replaced by a '\0' character in this case.
+ Returns the number of characters that would have been written (not counting
+ the terminating '\0' character) if n had been sufficiently large, if
+ successful, and a negative number if an encoding error ocurred.
+*/
int snprintf( char * _PDCLIB_restrict s, size_t n, const char * _PDCLIB_restrict format, ... );
+
+/* Equivalent to fprintf( stdout, format, ... ), except that the result is
+ written into the buffer pointed to by s, instead of stdout.
+*/
int sprintf( char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, ... );
+
+/* Equivalent to fscanf( stdin, format, ... ), except that the input is read
+ from the buffer pointed to by s, instead of stdin.
+*/
int sscanf( const char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, ... );
+
+/* Equivalent to fprintf( stream, format, ... ), except that the argument stack
+ is passed as va_list parameter. Note that va_list is not declared by
+ <stdio.h>.
+*/
int vfprintf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
+
+/* Equivalent to fscanf( stream, format, ... ), except that the argument stack
+ is passed as va_list parameter. Note that va_list is not declared by
+ <stdio.h>.
+*/
int vfscanf( FILE * _PDCLIB_restrict stream, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
+
+/* Equivalent to fprintf( stdout, format, ... ), except that the argument stack
+ is passed as va_list parameter. Note that va_list is not declared by
+ <stdio.h>.
+*/
int vprintf( const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
+
+/* Equivalent to fscanf( stdin, format, ... ), except that the argument stack
+ is passed as va_list parameter. Note that va_list is not declared by
+ <stdio.h>.
+*/
int vscanf( const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
+
+/* Equivalent to snprintf( s, n, format, ... ), except that the argument stack
+ is passed as va_list parameter. Note that va_list is not declared by
+ <stdio.h>.
+ */
int vsnprintf( char * _PDCLIB_restrict s, size_t n, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
+
+/* Equivalent to fprintf( stdout, format, ... ), except that the argument stack
+ is passed as va_list parameter, and the result is written to the buffer
+ pointed to by s, instead of stdout. Note that va_list is not declared by
+ <stdio.h>.
+*/
int vsprintf( char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
+
+/* Equivalent to fscanf( stdin, format, ... ), except that the argument stack
+ is passed as va_list parameter, and the input is read from the buffer
+ pointed to by s, instead of stdin. Note that va_list is not declared by
+ <stdio.h>.
+*/
int vsscanf( const char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, _PDCLIB_va_list arg );
/* Character input/output functions */