stdio-common/printf.h

   1 /* Copyright (C) 1991-1993,1995-2001,2006,2009
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _PRINTF_H
  21
  22 #define _PRINTF_H       1
  23 #include <features.h>
  24
  25 __BEGIN_DECLS
  26
  27 #define __need_FILE
  28 #include <stdio.h>
  29 #define __need_size_t
  30 #define __need_wchar_t
  31 #include <stddef.h>
  32 #include <stdarg.h>
  33
  34
  35 struct printf_info
  36 {
  37   int prec;                     /* Precision.  */
  38   int width;                    /* Width.  */
  39   wchar_t spec;                 /* Format letter.  */
  40   unsigned int is_long_double:1;/* L flag.  */
  41   unsigned int is_short:1;      /* h flag.  */
  42   unsigned int is_long:1;       /* l flag.  */
  43   unsigned int alt:1;           /* # flag.  */
  44   unsigned int space:1;         /* Space flag.  */
  45   unsigned int left:1;          /* - flag.  */
  46   unsigned int showsign:1;      /* + flag.  */
  47   unsigned int group:1;         /* ' flag.  */
  48   unsigned int extra:1;         /* For special use.  */
  49   unsigned int is_char:1;       /* hh flag.  */
  50   unsigned int wide:1;          /* Nonzero for wide character streams.  */
  51   unsigned int i18n:1;          /* I flag.  */
  52   unsigned int __pad:4;         /* Unused so far.  */
  53   unsigned short int user;      /* Bits for user-installed modifiers.  */
  54   wchar_t pad;                  /* Padding character.  */
  55 };
  56
  57
  58 /* Type of a printf specifier-handler function.
  59    STREAM is the FILE on which to write output.
  60    INFO gives information about the format specification.
  61    ARGS is a vector of pointers to the argument data;
  62    the number of pointers will be the number returned
  63    by the associated arginfo function for the same INFO.
  64
  65    The function should return the number of characters written,
  66    or -1 for errors.  */
  67
  68 typedef int printf_function (FILE *__stream,
  69                              __const struct printf_info *__info,
  70                              __const void *__const *__args);
  71
  72 /* Type of a printf specifier-arginfo function.
  73    INFO gives information about the format specification.
  74    N, ARGTYPES, *SIZE has to contain the size of the parameter for
  75    user-defined types, and return value are as for parse_printf_format
  76    except that -1 should be returned if the handler cannot handle
  77    this case.  This allows to partially overwrite the functionality
  78    of existing format specifiers.  */
  79
  80 typedef int printf_arginfo_size_function (__const struct printf_info *__info,
  81                                           size_t __n, int *__argtypes,
  82                                           int *__size);
  83
  84 /* Old version of 'printf_arginfo_function' without a SIZE parameter.  */
  85
  86 typedef int printf_arginfo_function (__const struct printf_info *__info,
  87                                      size_t __n, int *__argtypes);
  88
  89 /* Type of a function to get a value of a user-defined from the
  90    variable argument list.  */
  91 typedef void printf_va_arg_function (void *__mem, va_list *__ap);
  92
  93
  94 /* Register FUNC to be called to format SPEC specifiers; ARGINFO must be
  95    specified to determine how many arguments a SPEC conversion requires and
  96    what their types are.  */
  97
  98 extern int register_printf_specifier (int __spec, printf_function __func,
  99                                       printf_arginfo_size_function __arginfo)
 100   __THROW;
 101
 102
 103 /* Obsolete interface similar to register_printf_specifier.  It can only
 104    handle basic data types because the ARGINFO callback does not return
 105    information on the size of the user-defined type.  */
 106
 107 extern int register_printf_function (int __spec, printf_function __func,
 108                                      printf_arginfo_function __arginfo)
 109   __THROW __attribute_deprecated__;
 110
 111
 112 /* Register a new modifier character sequence.  If the call succeeds
 113    it returns a positive value representing the bit set in the USER
 114    field in 'struct printf_info'.  */
 115
 116 extern int register_printf_modifier (__const wchar_t *__str) __wur __THROW;
 117
 118
 119 /* Register variable argument handler for user type.  The return value
 120    is to be used in ARGINFO functions to signal the use of the
 121    type.  */
 122 extern int register_printf_type (printf_va_arg_function __fct) __wur __THROW;
 123
 124
 125 /* Parse FMT, and fill in N elements of ARGTYPES with the
 126    types needed for the conversions FMT specifies.  Returns
 127    the number of arguments required by FMT.
 128
 129    The ARGINFO function registered with a user-defined format is passed a
 130    `struct printf_info' describing the format spec being parsed.  A width
 131    or precision of INT_MIN means a `*' was used to indicate that the
 132    width/precision will come from an arg.  The function should fill in the
 133    array it is passed with the types of the arguments it wants, and return
 134    the number of arguments it wants.  */
 135
 136 extern size_t parse_printf_format (__const char *__restrict __fmt, size_t __n,
 137                                    int *__restrict __argtypes) __THROW;
 138
 139
 140 /* Codes returned by `parse_printf_format' for basic types.
 141
 142    These values cover all the standard format specifications.
 143    Users can reserve new values after PA_LAST for their own types
 144    using 'register_printf_type'.  */
 145
 146 enum
 147 {                               /* C type: */
 148   PA_INT,                       /* int */
 149   PA_CHAR,                      /* int, cast to char */
 150   PA_WCHAR,                     /* wide char */
 151   PA_STRING,                    /* const char *, a '\0'-terminated string */
 152   PA_WSTRING,                   /* const wchar_t *, wide character string */
 153   PA_POINTER,                   /* void * */
 154   PA_FLOAT,                     /* float */
 155   PA_DOUBLE,                    /* double */
 156   PA_LAST
 157 };
 158
 159 /* Flag bits that can be set in a type returned by `parse_printf_format'.  */
 160 #define PA_FLAG_MASK            0xff00
 161 #define PA_FLAG_LONG_LONG       (1 << 8)
 162 #define PA_FLAG_LONG_DOUBLE     PA_FLAG_LONG_LONG
 163 #define PA_FLAG_LONG            (1 << 9)
 164 #define PA_FLAG_SHORT           (1 << 10)
 165 #define PA_FLAG_PTR             (1 << 11)
 166
 167
 168
 169 /* Function which can be registered as `printf'-handlers.  */
 170
 171 /* Print floating point value using using abbreviations for the orders
 172    of magnitude used for numbers ('k' for kilo, 'm' for mega etc).  If
 173    the format specifier is a uppercase character powers of 1000 are
 174    used.  Otherwise powers of 1024.  */
 175 extern int printf_size (FILE *__restrict __fp,
 176                         __const struct printf_info *__info,
 177                         __const void *__const *__restrict __args) __THROW;
 178
 179 /* This is the appropriate argument information function for `printf_size'.  */
 180 extern int printf_size_info (__const struct printf_info *__restrict
 181                              __info, size_t __n, int *__restrict __argtypes)
 182      __THROW;
 183
 184 #ifdef __LDBL_COMPAT
 185 # include <bits/printf-ldbl.h>
 186 #endif
 187
 188 __END_DECLS
 189
 190 #endif /* printf.h  */