libkernaux/examples/printf_file_va.c

37 lines
836 B
C

#include <kernaux/printf.h>
#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#define BUFFER_SIZE 1024
static const char *const data = "foobar";
static char buffer[BUFFER_SIZE];
static size_t buffer_index = 0;
static void my_putchar(const char chr, void *const arg)
{
assert(arg == data);
if (buffer_index >= BUFFER_SIZE) abort();
buffer[buffer_index++] = chr;
}
static int my_printf(const char *const format, ...)
{
va_list va;
va_start(va, format);
const int result = kernaux_vfprintf(my_putchar, (void*)data, format, va);
va_end(va);
return result;
}
void example_main()
{
const int result = my_printf("Hello, %s! Session ID: %u.", "Alex", 123);
assert((size_t)result == strlen(buffer));
assert(strcmp(buffer, "Hello, Alex! Session ID: 123.") == 0);
}