src/include/gpxe/vsprintf.h

   1 #ifndef _GPXE_VSPRINTF_H
   2 #define _GPXE_VSPRINTF_H
   3
   4 /** @file
   5  *
   6  * printf() and friends
   7  *
   8  * Etherboot's printf() functions understand the following subset of
   9  * the standard C printf()'s format specifiers:
  10  *
  11  *      - Flag characters
  12  *              - '#'           - Alternate form (i.e. "0x" prefix)
  13  *              - '0'           - Zero-pad
  14  *      - Field widths
  15  *      - Length modifiers
  16  *              - 'hh'          - Signed / unsigned char
  17  *              - 'h'           - Signed / unsigned short
  18  *              - 'l'           - Signed / unsigned long
  19  *              - 'll'          - Signed / unsigned long long
  20  *              - 'z'           - Signed / unsigned size_t
  21  *      - Conversion specifiers
  22  *              - 'd'           - Signed decimal
  23  *              - 'x','X'       - Unsigned hexadecimal
  24  *              - 'c'           - Character
  25  *              - 's'           - String
  26  *              - 'p'           - Pointer
  27  *
  28  * Hexadecimal numbers are always zero-padded to the specified field
  29  * width (if any); decimal numbers are always space-padded.  Decimal
  30  * long longs are not supported.
  31  *
  32  */
  33
  34 FILE_LICENCE ( GPL2_OR_LATER );
  35
  36 #include <stdint.h>
  37 #include <stdarg.h>
  38 #include <stdio.h>
  39
  40 /**
  41  * A printf context
  42  *
  43  * Contexts are used in order to be able to share code between
  44  * vprintf() and vsnprintf(), without requiring the allocation of a
  45  * buffer for vprintf().
  46  */
  47 struct printf_context {
  48         /**
  49          * Character handler
  50          *
  51          * @v ctx       Context
  52          * @v c         Character
  53          *
  54          * This method is called for each character written to the
  55          * formatted string.
  56          */
  57         void ( * handler ) ( struct printf_context *ctx, unsigned int c );
  58         /** Length of formatted string
  59          *
  60          * When handler() is called, @len will be set to the number of
  61          * characters written so far (i.e. zero for the first call to
  62          * handler()).
  63          */
  64         size_t len;
  65 };
  66
  67 extern size_t vcprintf ( struct printf_context *ctx, const char *fmt,
  68                          va_list args );
  69 extern int vssnprintf ( char *buf, ssize_t ssize, const char *fmt,
  70                         va_list args );
  71 extern int __attribute__ (( format ( printf, 3, 4 ) ))
  72 ssnprintf ( char *buf, ssize_t ssize, const char *fmt, ... );
  73
  74 #endif /* _GPXE_VSPRINTF_H */