Simple memory allocation examples

chp9/malloc.c

@@ -0,0 +1,45 @@
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void *xmalloc(size_t size);
+
+int main(void)
+{
+	char *str = xmalloc(1024);
+	char *src = "HelloWorld";
+	for (int i = 0; i < (int)strlen(src); i++)
+		str[i] = src[i];
+	printf("%s\n", str);
+
+	int *numbers = calloc(10, sizeof(int));
+	for (int i = 0; i < 10; i++) {
+		numbers[i] = i + 1;
+		printf("%d ", numbers[i]);
+	}
+
+	printf("\n");
+
+	int *p = realloc(numbers, 2 * sizeof(int));
+	if (!p) {
+		perror("realloc");
+		exit(1);
+	}
+
+	for (int i = 0; i < 20; i++) {
+		printf("%d ", p[i]);
+	}
+	return EXIT_SUCCESS;
+}
+
+void *xmalloc(size_t size)
+{
+	void *p;
+	p = malloc(size);
+	if (!p) {
+		perror("xmalloc");
+		exit(1);
+	}
+	return p;
+}