Add new code

Signed-off-by: Carlos Maiolino <[email protected]>

2 files changed, 89 insertions, 0 deletions

diff --git a/C/Pointers/addr.c b/C/Pointers/addr.c
new file mode 100644
index 0000000..f77a9c6
--- /dev/null
+++ b/C/Pointers/addr.c
@@ -0,0 +1,47 @@
+#include <stdio.h>
+
+int main (void)
+{
+	/*
+	 * Arrays in C are just sequential data items
+	 * stored in a memory location
+	 * The address of the array, is the same as the first
+	 * element in the array
+	 * The name of the array is also the address of the array.
+	 */
+
+	char str1[] = "Hello cruel world"; /* \0 is automatically added */
+
+	/* Those variables look the same, but they are not. */
+
+	/* This is an array */
+
+	/*
+	 * str2, is the address of the "ARRAY" which the characters
+	 * of the string are stored
+	 * str2 is not a 'pointer' to the location of the Hello char array
+	 * str2 IS THE LOCATION of the array.
+	 */
+	char str2[] = "Hello";
+
+	/*
+	 * This is a pointer.
+	 *
+	 * Whose value is not the string, but the - address of that string -
+	 *
+	 */
+	char *str3 = "Goodbye";
+
+	str3 = NULL;
+	str2 = NULL;
+	/*
+	 * &str1, &str1[0] and str1, all points to the very same address.
+	 *
+	 * The array name, str1, is also the address of the array.
+	 * */
+	printf("%s, %c, %d, %d %d\n", str1, str1[0], &str1, &str1[0], str1);
+
+	printf("%p %p %s\n", &str2, str2, str2);
+	printf("%p %p %s\n", &str3, str3, str3);
+
+}
diff --git a/C/Pointers/multi_indirection.c b/C/Pointers/multi_indirection.c
new file mode 100644
index 0000000..92b677c
--- /dev/null
+++ b/C/Pointers/multi_indirection.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+
+char *words[3];
+
+int main(void)
+{
+	char *pc;
+	char **ppc;
+	int i;
+	char *foo, *bar;
+
+	printf("multiple indirection example\n");
+
+	words[0] = "zero";
+	foo = "FOO";
+	words[1] = "one";
+	bar = "BAR";
+	words[2] = "two";
+
+	for (int i = 0; i < 3; i++)
+		printf("%s\n", words[i]);
+
+	printf("Print each char in each string...\n");
+
+	ppc = words;
+
+	printf("Addr of array head %p\n", words);
+	for (i = 0; i < 3; i ++) {
+		ppc = words + i;
+		pc = *ppc;
+
+		printf("array %d -> loc %p -> deref: %p\n", i, &words[i], *ppc);
+		while (*pc != 0) {
+			printf("addr: %p - content: %c \n", pc, *pc);
+			pc += 1;
+		}
+
+		printf("\n");
+	}
+
+	return 0;
+}