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Author: garyexplains

ptr_to_struct/struct1.c

@@ -0,0 +1,17 @@
+// gcc -o struct1 struct1.c 
+
+#include <stdio.h>
+
+struct point {
+    int x;
+    int y;
+};
+
+int main() {
+    struct point p;
+
+    p.x = 10;
+    p.y = 42;
+
+    printf("x is %d and y is %d\n", p.x, p.y);
+}

ptr_to_struct/struct2.c

@@ -0,0 +1,14 @@
+// gcc -o struct2 struct2.c 
+
+#include <stdio.h>
+
+struct point {
+    int x;
+    int y;
+};
+
+int main() {
+    struct point p = {11, 43};
+
+    printf("x is %d and y is %d\n", p.x, p.y);
+}

ptr_to_struct/struct3.c

@@ -0,0 +1,17 @@
+// gcc -o struct3 struct3.c 
+
+#include <stdio.h>
+
+struct point {
+    int x;
+    int y;
+};
+
+int main() {
+    struct point q = {12, 44};
+    struct point p;
+
+    p = q;
+
+    printf("x is %d and y is %d\n", p.x, p.y);
+}

ptr_to_struct/struct3a.c

@@ -0,0 +1,20 @@
+// gcc -o struct3a struct3a.c 
+
+#include <stdio.h>
+
+struct point {
+    int x;
+    int y;
+};
+
+int main() {
+    struct point q = {12, 44};
+    struct point p;
+
+    p = q;
+    p.x = p.x + 1;
+    p.y = p.y + 1;
+
+    printf("q: x is %d and y is %d\n", q.x, q.y);
+    printf("p: x is %d and y is %d\n", p.x, p.y);
+}

ptr_to_struct/struct4.c

@@ -0,0 +1,14 @@
+// gcc -o struct4 struct4.c 
+
+#include <stdio.h>
+
+typedef struct point {
+    int x;
+    int y;
+} point_t;
+
+int main() {
+    point_t p = {13, 45};
+
+    printf("x is %d and y is %d\n", p.x, p.y);
+}

ptr_to_struct/struct5.c

@@ -0,0 +1,24 @@
+// gcc -o struct5 struct5.c 
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct point {
+    int x;
+    int y;
+    char desc64[64];
+} point_t;
+
+int main() {
+    point_t *p = (point_t *) malloc(sizeof(point_t));
+
+    p->x = 14;
+    p->y = 46;
+    strcpy(p->desc64, "A point");
+
+    printf("x is %d and y is %d and it is a '%s' and its size is %d\n",
+                            p->x, p->y, p->desc64, (int) sizeof(point_t));
+
+    free(p);
+}

ptr_to_struct/struct6.c

@@ -0,0 +1,33 @@
+// gcc -o struct6 struct6.c 
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct point {
+    int x;
+    int y;
+    char desc64[64];
+} point_t;
+
+int main() {
+    point_t *p = (point_t *) malloc(sizeof(point_t));
+    point_t *q;
+
+    p->x = 14;
+    p->y = 46;
+    strcpy(p->desc64, "A point");
+
+    printf("x is %d and y is %d and it is a '%s' and its size is %d\n",
+                            p->x, p->y, p->desc64, (int) sizeof(point_t));
+
+    q = p;
+
+    q->x = 15;
+    q->y = 47;
+
+    printf("x is %d and y is %d\n", p->x, p->y);
+
+    free(p);
+    // free(q) /* NO */
+}

ptr_to_struct/struct7.c

@@ -0,0 +1,30 @@
+// gcc -o struct7 struct7.c 
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct point {
+    int x;
+    int y;
+    char desc64[64];
+} point_t;
+
+void point_factor2(point_t *apoint) {
+    apoint->x = apoint->x * 2;
+    apoint->y = apoint->y * 2;
+}
+
+int main() {
+    point_t *p = (point_t *) malloc(sizeof(point_t));
+
+    p->x = 14;
+    p->y = 46;
+    strcpy(p->desc64, "A point");
+
+    point_factor2(p);
+
+    printf("x is %d and y is %d\n", p->x, p->y);
+
+    free(p);
+}

ptr_to_struct/struct8.c

@@ -0,0 +1,32 @@
+// gcc -o struct8 struct8.c 
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct point {
+    int x;
+    int y;
+    char desc64[64];
+} point_t;
+
+void point_add(point_t *a, const point_t *b) {
+    a->x = a->x + b->x;
+    a->y = a->y + b->y;
+    // b->x = 0; /* No, as b is const */
+}
+
+int main() {
+    point_t *p1 = (point_t *) malloc(sizeof(point_t));
+    point_t p2 = {10, 20, "Another point"};
+
+    p1->x = 14;
+    p1->y = 46;
+    strcpy(p1->desc64, "A point");
+
+    point_add(p1, &p2);
+
+    printf("x is %d and y is %d\n", p1->x, p1->y);
+
+    free(p1);
+}