From de6e1a02d43a3836f422913b9a85ebe093b38d62 Mon Sep 17 00:00:00 2001
From: Alex Kotov <kotovalexarian@gmail.com>
Date: Mon, 7 Dec 2020 05:27:42 +0500
Subject: [PATCH] Add example for "kernaux_printf_va"

---
 .gitignore           |  1 +
 Makefile.am          |  5 +++++
 examples/printf_va.c | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)
 create mode 100644 examples/printf_va.c

diff --git a/.gitignore b/.gitignore
index 8c48307..e8dfedd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -34,6 +34,7 @@
 
 /examples/cmdline
 /examples/printf
+/examples/printf_va
 /tests/multiboot2_print1
 /tests/multiboot2_print2
 /tests/test_cmdline
diff --git a/Makefile.am b/Makefile.am
index e2d8794..9827e06 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -11,6 +11,7 @@ lib_LIBRARIES = libkernaux.a
 
 TESTS = \
 	examples/printf \
+	examples/printf_va \
 	tests/test_printf \
 	tests/test_stdlib
 
@@ -62,6 +63,10 @@ examples_printf_SOURCES = \
 	$(libkernaux_a_SOURCES) \
 	examples/printf.c
 
+examples_printf_va_SOURCES = \
+	$(libkernaux_a_SOURCES) \
+	examples/printf_va.c
+
 tests_multiboot2_print1_SOURCES = \
 	$(libkernaux_a_SOURCES) \
 	tests/multiboot2_print1.c
diff --git a/examples/printf_va.c b/examples/printf_va.c
new file mode 100644
index 0000000..72fad69
--- /dev/null
+++ b/examples/printf_va.c
@@ -0,0 +1,37 @@
+#include <kernaux/printf.h>
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define BUFFER_SIZE 1024
+
+static char buffer[BUFFER_SIZE];
+static unsigned int buffer_index;
+
+static void my_putchar(const char chr)
+{
+    if (buffer_index >= BUFFER_SIZE) abort();
+    buffer[buffer_index++] = chr;
+}
+
+static void my_printf(const char *const format, ...)
+{
+    va_list va;
+    va_start(va, format);
+    kernaux_printf_va(my_putchar, format, va);
+    va_end(va);
+}
+
+int main()
+{
+    memset(buffer, '\0', sizeof(buffer));
+    buffer_index = 0;
+    my_printf("Hello, %s! Session ID: %u.", "Alex", 123);
+    assert(strcmp(buffer, "Hello, Alex! Session ID: 123.") == 0);
+
+    printf("OK!\n");
+
+    return 0;
+}