vsprintf.h

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#ifndef _IPXE_VSPRINTF_H
#define _IPXE_VSPRINTF_H

/** @file
 *
 * printf() and friends
 *
 * Etherboot's printf() functions understand the following subset of
 * the standard C printf()'s format specifiers:
 *
 *      - Flag characters
 *              - '#'           - Alternate form (i.e. "0x" prefix)
 *              - '0'           - Zero-pad
 *      - Field widths
 *      - Length modifiers
 *              - 'hh'          - Signed / unsigned char
 *              - 'h'           - Signed / unsigned short
 *              - 'l'           - Signed / unsigned long
 *              - 'll'          - Signed / unsigned long long
 *              - 'z'           - Signed / unsigned size_t
 *      - Conversion specifiers
 *              - 'd'           - Signed decimal
 *              - 'x','X'       - Unsigned hexadecimal
 *              - 'c'           - Character
 *              - 's'           - String
 *              - 'p'           - Pointer
 *
 * Hexadecimal numbers are always zero-padded to the specified field
 * width (if any); decimal numbers are always space-padded.  Decimal
 * long longs are not supported.
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
FILE_SECBOOT ( PERMITTED );

#include <stdint.h>
#include <stdarg.h>
#include <stdio.h>

/**
 * A printf context
 *
 * Contexts are used in order to be able to share code between
 * vprintf() and vsnprintf(), without requiring the allocation of a
 * buffer for vprintf().
 */
struct printf_context {
        /**
         * Character handler
         *
         * @v ctx       Context
         * @v c         Character
         *
         * This method is called for each character written to the
         * formatted string.
         */
        void ( * handler ) ( struct printf_context *ctx, unsigned int c );
        /** Length of formatted string
         *
         * When handler() is called, @len will be set to the number of
         * characters written so far (i.e. zero for the first call to
         * handler()).
         */
        size_t len;
};

extern size_t vcprintf ( struct printf_context *ctx, const char *fmt,
                         va_list args );
extern int vssnprintf ( char *buf, ssize_t ssize, const char *fmt,
                        va_list args );
extern int __attribute__ (( format ( printf, 3, 4 ) ))
ssnprintf ( char *buf, ssize_t ssize, const char *fmt, ... );

#endif /* _IPXE_VSPRINTF_H */