40 lines
1.0 KiB
C
40 lines
1.0 KiB
C
#include <stdio.h>
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// internal depency
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#include "internal/printf.h"
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static void disp_char(struct printf_opt *opt, char n)
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{
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// Check write possibility
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if (opt->buffer_cursor < opt->str_size - 1) {
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opt->str[opt->buffer_cursor] = n;
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opt->buffer_cursor = opt->buffer_cursor + 1;
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}
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}
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static void disp_fflush(struct printf_opt *opt)
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{
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opt->str[opt->buffer_cursor] = '\0';
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}
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/*
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** The functions vsnprintf() are equivalent to the snprintf() except that they
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** are called with a va_list instead of a variable number of arguments. These
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** functions do not call the va_end macro. Because they invoke the va_arg macro,
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** the value of ap is undefined after the call.
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*/
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int vsnprintf(char *restrict str, size_t size, const char *restrict format,
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va_list ap)
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{
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extern int printf_common(struct printf_opt *opt,
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const char *restrict format);
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struct printf_opt opt;
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opt.str = str;
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opt.str_size = size;
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opt.disp_char = &disp_char;
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opt.disp_fflush = &disp_fflush;
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va_copy(opt.ap, ap);
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return (printf_common(&opt, format) + 1);
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}
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