+#define _PDCLIB_INTMAX_MIN _PDCLIB_concat( _PDCLIB_concat( _PDCLIB_, _PDCLIB_INTMAX ), _MIN )
+#define _PDCLIB_INTMAX_MAX _PDCLIB_concat( _PDCLIB_concat( _PDCLIB_, _PDCLIB_INTMAX ), _MAX )
+#define _PDCLIB_UINTMAX_MAX _PDCLIB_concat( _PDCLIB_concat( _PDCLIB_U, _PDCLIB_INTMAX ), _MAX )
+#define _PDCLIB_INTMAX_C( value ) _PDCLIB_concat( value, _PDCLIB_INTMAX_LITERAL )
+#define _PDCLIB_UINTMAX_C( value ) _PDCLIB_concat( value, _PDCLIB_concat( u, _PDCLIB_INTMAX_LITERAL ) )
+
+/* -------------------------------------------------------------------------- */
+/* Various <stdio.h> internals */
+/* -------------------------------------------------------------------------- */
+
+/* Flags for representing mode (see fopen()). Note these must fit the same
+ status field as the _IO?BF flags in <stdio.h> and the internal flags below.
+*/
+#define _PDCLIB_FREAD 8u
+#define _PDCLIB_FWRITE 16u
+#define _PDCLIB_FAPPEND 32u
+#define _PDCLIB_FRW 64u
+#define _PDCLIB_FBIN 128u
+
+/* Internal flags, made to fit the same status field as the flags above. */
+#define _PDCLIB_LIBBUFFER 512u
+#define _PDCLIB_ERRORFLAG 1024u
+#define _PDCLIB_EOFFLAG 2048u
+#define _PDCLIB_WIDESTREAM 4096u
+#define _PDCLIB_BYTESTREAM 8192u
+
+/* Position / status structure for getpos() / fsetpos(). */
+struct _PDCLIB_fpos_t
+{
+ _PDCLIB_uint64_t offset; /* File position offset */
+ int status; /* Multibyte parsing state (unused, reserved) */
+};
+
+/* FILE structure */
+struct _PDCLIB_file_t
+{
+ _PDCLIB_fd_t handle; /* OS file handle */
+ char * buffer; /* Pointer to buffer memory */
+ _PDCLIB_size_t bufsize; /* Size of buffer */
+ _PDCLIB_size_t bufidx; /* Index of current position in buffer */
+ _PDCLIB_size_t bufend; /* Index of last pre-read character in buffer */
+ struct _PDCLIB_fpos_t pos; /* Offset and multibyte parsing state */
+ _PDCLIB_size_t ungetidx; /* Number of ungetc()'ed characters */
+ unsigned char * ungetbuf; /* ungetc() buffer */
+ unsigned int status; /* Status flags; see above */
+ /* multibyte parsing status to be added later */
+ char * filename; /* Name the current stream has been opened with */
+ struct _PDCLIB_file_t * next; /* Pointer to next struct (internal) */
+};
+
+/* -------------------------------------------------------------------------- */
+/* Internal data types */
+/* -------------------------------------------------------------------------- */
+
+/* Structure required by both atexit() and exit() for handling atexit functions */
+struct _PDCLIB_exitfunc_t
+{
+ struct _PDCLIB_exitfunc_t * next;
+ void (*func)( void );
+};
+
+/* Structures required by malloc(), realloc(), and free(). */
+struct _PDCLIB_headnode_t
+{
+ struct _PDCLIB_memnode_t * first;
+ struct _PDCLIB_memnode_t * last;
+};
+
+struct _PDCLIB_memnode_t
+{
+ _PDCLIB_size_t size;
+ struct _PDCLIB_memnode_t * next;
+};
+
+/* Status structure required by _PDCLIB_print(). */
+struct _PDCLIB_status_t
+{
+ int base; /* base to which the value shall be converted */
+ _PDCLIB_int_fast32_t flags; /* flags and length modifiers */
+ _PDCLIB_size_t n; /* print: maximum characters to be written */
+ /* scan: number matched conversion specifiers */
+ _PDCLIB_size_t i; /* number of characters already written */
+ _PDCLIB_size_t this; /* output chars in the current conversion */
+ char * s; /* print: target buffer */
+ /* scan: source string */
+ _PDCLIB_size_t width; /* width of current field */
+ _PDCLIB_size_t prec; /* precision of current field */
+ struct _PDCLIB_file_t * stream;/* for to-stream output */
+ _PDCLIB_va_list arg; /* argument stack passed to the printf function */
+};
+
+/* -------------------------------------------------------------------------- */
+/* Declaration of helper functions (implemented in functions/_PDCLIB). */
+/* -------------------------------------------------------------------------- */
+
+/* This is the main function called by atoi(), atol() and atoll(). */
+_PDCLIB_intmax_t _PDCLIB_atomax( const char * s );
+
+/* Two helper functions used by strtol(), strtoul() and long long variants. */
+const char * _PDCLIB_strtox_prelim( const char * p, char * sign, int * base );
+_PDCLIB_uintmax_t _PDCLIB_strtox_main( const char ** p, unsigned int base, _PDCLIB_uintmax_t error, _PDCLIB_uintmax_t limval, int limdigit, char * sign );
+
+/* Digits arrays used by various integer conversion functions */
+extern char _PDCLIB_digits[];
+extern char _PDCLIB_Xdigits[];
+
+/* The worker for all printf() type of functions. The pointer spec should point
+ to the introducing '%' of a conversion specifier. The status structure is to
+ be that of the current printf() function, of which the members n, s, stream
+ and arg will be preserved; i will be updated; and all others will be trashed
+ by the function.
+ Returns a pointer to the first character not parsed as conversion specifier.
+*/
+const char * _PDCLIB_print( const char * spec, struct _PDCLIB_status_t * status );
+
+/* The worker for all scanf() type of functions. The pointer spec should point
+ to the introducing '%' of a conversion specifier. The status structure is to
+ be that of the current scanf() function, of which the member stream will be
+ preserved, n, i, and s will be updated; and all others will be trashed by the
+ function.
+ Returns a pointer to the first character not parsed as conversion specifier.
+*/
+const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status );
+
+/* Parsing any fopen() style filemode string into a number of flags. */
+unsigned int _PDCLIB_filemode( const char * mode );
+
+/* Sanity checking and preparing of read buffer, should be called first thing
+ by any stdio read-data function.
+ Returns 0 on success, EOF on error.
+ On error, EOF / error flags and errno are set appropriately.
+*/
+int _PDCLIB_prepread( struct _PDCLIB_file_t * stream );
+
+/* Sanity checking, should be called first thing by any stdio write-data
+ function.
+ Returns 0 on success, EOF on error.
+ On error, error flags and errno are set appropriately.
+*/
+int _PDCLIB_prepwrite( struct _PDCLIB_file_t * stream );
+
+/* -------------------------------------------------------------------------- */
+/* errno */
+/* -------------------------------------------------------------------------- */
+
+extern int _PDCLIB_errno;
+int * _PDCLIB_errno_func( void );
+
+/* ERANGE and EDOM are specified by the standard. */
+#define _PDCLIB_ERANGE 1
+#define _PDCLIB_EDOM 2
+/* Used in the example implementation for any kind of I/O error. */
+#define _PDCLIB_EIO 3
+/* Used in the example implementation for "unknown error". */
+#define _PDCLIB_EUNKNOWN 4
+/* Used in the example implementation for "invalid parameter value". */
+#define _PDCLIB_EINVAL 5
+/* Used in the example implementation for "I/O retries exceeded". */
+#define _PDCLIB_ERETRY 6
+