mdw@git.distorted.org.uk Git - mLib/blob - utils/gprintf.h

   1 /* -*-c-*-
   2  *
   3  * Generalized string formatting
   4  *
   5  * (c) 2023 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU Library General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  20  * License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib.  If not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  25  * USA.
  26  */
  27
  28 #ifndef MLIB_GPRINTF_H
  29 #define MLIB_GPRINTF_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <stdarg.h>
  38
  39 #ifndef MLIB_MACROS_H
  40 #  include "macros.h"
  41 #endif
  42
  43 /*----- Data structures ---------------------------------------------------*/
  44
  45 struct gprintf_ops {
  46   int (*putch)(void */*out*/, int /*ch*/);
  47   int (*putm)(void */*out*/, const char */*p*/, size_t /*sz*/);
  48   PRINTF_LIKE(3, 4) int (*nputf)
  49     (void */*out*/, size_t /*maxsz*/, const char */*p*/, ...);
  50 };
  51
  52 extern const struct gprintf_ops file_printops;
  53
  54 /*----- Functions provided ------------------------------------------------*/
  55
  56 /* --- @vgprintf@ --- *
  57  *
  58  * Arguments:   @const struct gprintf_ops *ops@ = output operations
  59  *              @void *out@ = context for output operations
  60  *              @const char *p@ = pointer to @printf@-style format string
  61  *              @va_list *ap@ = argument handle
  62  *
  63  * Returns:     The number of characters written to the string.
  64  *
  65  * Use:         As for @gprintf@, but takes a reified argument tail.
  66  */
  67
  68 extern int vgprintf(const struct gprintf_ops */*ops*/, void */*out*/,
  69                     const char */*p*/, va_list */*ap*/);
  70
  71 /* --- @gprintf@ --- *
  72  *
  73  * Arguments:   @const struct gprintf_ops *ops@ = output operations
  74  *              @void *out@ = context for output operations
  75  *              @const char *p@ = pointer to @printf@-style format string
  76  *              @...@ = argument handle
  77  *
  78  * Returns:     The number of characters written to the string.
  79  *
  80  * Use:         Formats a @printf@-like message and writes the result using
  81  *              the given output operations.  This is the backend machinery
  82  *              for @dstr_putf@, for example.
  83  */
  84
  85 extern int PRINTF_LIKE(3, 4)
  86   gprintf(const struct gprintf_ops */*ops*/, void */*out*/,
  87           const char */*p*/, ...);
  88
  89 /*----- That's all, folks -------------------------------------------------*/
  90
  91 #ifdef __cplusplus
  92   }
  93 #endif
  94
  95 #endif