.

bac2/os/chap2/Makefile

@@ -0,0 +1,26 @@
+.PHONY: clean, mrproper
+CC = gcc
+CFLAGS = -g -Wall
+
+all: ex3 ex4
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+ex3: ex3.o
+	$(CC) $(CFLAGS) -o $@ $+
+
+ex4: ex4.o
+	$(CC) $(CFLAGS) -o $@ $+
+
+ex5: ex5.o
+	$(CC) $(CFLAGS) -o $@ $+
+
+clean:
+	rm -f *.o core.*
+
+mrproper: clean
+	rm -f ex3 ex4 ex5
+
+run: ex5
+	./ex5

bac2/os/chap2/ex1.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_SIZE 100
+
+int main(void)
+{
+	char* blop[TEST_SIZE];
+	for (int i = 0; i < TEST_SIZE; ++i) {
+		blop[i] = malloc(sizeof(char));
+		printf("%p\n", blop[i]);
+	}
+	while(1);
+}

bac2/os/chap2/ex2.c

@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char* expand_tabs(const char* string);
+
+int main(void)
+{
+	const char* str = "This is a text	This is another one. ' ' <- space; '	' <-tab";
+	printf("%s - %d\n", str, (int)strlen(str));
+	printf("%s - %d\n", expand_tabs(str),(int) strlen(expand_tabs(str)));
+	
+}
+
+char* expand_tabs(const char* string){
+	int tab_count = 0, letter_count = 0;
+	for(int i = 0; string[i] != '\0'; i++){
+		letter_count++;
+		if(string[i] == '\t')
+			tab_count++;
+	}
+	char* ret = malloc(sizeof(char) * letter_count + 3*tab_count);
+	char* filler = ret;
+	for(int i = 0; string[i] != '\0'; i++){
+		if(string[i] == '\t'){
+			for (int j = 0; j < 4; ++j) {
+				*(filler++) = ' ';
+			}
+		}else{
+			*(filler++) = string[i];
+		}
+	}
+	return ret;
+}

bac2/os/chap2/ex3.c

@@ -0,0 +1,62 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+#define print_vec(vec) for (int i = 0; i < (vec)->size; ++i) { printf("%d, ", (vec)->data[i]); } printf("\n")
+
+struct vec {
+	int size;
+	int *data;
+};
+
+
+struct vec* new(unsigned int n);
+struct vec* add(const struct vec *v, const struct vec *w);
+struct vec* smul(double s, const struct vec *v);
+
+int main(void)
+{
+	struct vec *v = new(4);
+	v->data[0] = 1;
+	v->data[1] = 2;
+	v->data[2] = 3;
+	v->data[3] = 4;
+	print_vec(v);
+
+	struct vec *w = new(4);
+	w->data[0] = 5;
+	w->data[1] = 6;
+	w->data[2] = 7;
+	w->data[3] = 8;
+	print_vec(w);
+
+	struct vec *added = add(v, w);
+	print_vec(added);
+
+	struct vec *multiplied = smul(3, v);
+	print_vec(multiplied);
+}
+
+struct vec* new(unsigned int n){
+	struct vec* ret = malloc(sizeof(struct vec));
+	ret->size = n;
+	ret->data = malloc(sizeof(int) * n);
+	return ret;
+}
+
+
+struct vec* add(const struct vec *v, const struct vec *w){
+	if(v->size != w->size)
+		return NULL;
+	struct vec *ret = new(v->size);
+	for (int i = 0; i < v->size; ++i) {
+		ret->data[i] = v->data[i] + w->data[i];
+	}
+	return ret;
+}
+struct vec* smul(double s, const struct vec *v){
+	struct vec *ret = new(v->size);
+	for (int i = 0; i < v->size; ++i) {
+		ret->data[i] = v->data[i] * s;
+	}
+	return ret;
+}

bac2/os/chap2/ex4.c

@@ -0,0 +1,61 @@
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define AT(mat, x, y) ((mat)->data[((x)-1) + ( ((y)-1) * ((mat)->w) )])
+
+#define PRINT_MAT(mat) for (int i = 1; i <= (mat)->h; ++i) { for (int j = 1; j <= (mat)->w; ++j) { printf("%d,", AT((mat),(j), (i))); } printf("\n"); } printf("\n");
+
+typedef struct {
+	uint8_t w, h;
+	int *data;
+} MAT;
+
+MAT *new(uint8_t, uint8_t);
+MAT *mul(MAT*, MAT*);
+
+int main(void)
+{
+	MAT* a = new(3, 2);
+	MAT* b = new(3, 3);
+	MAT* mult;
+
+
+	AT(a, 1, 1) = 0; AT(a, 2, 1) = 1; AT(a, 3, 1) = 2;
+	AT(a, 1, 2) = 3; AT(a, 2, 2) = 4; AT(a, 3, 2) = 5;
+	/* AT(a, 1, 3) = 6; AT(a, 2, 3) = 7; AT(a, 3, 3) = 8; */
+	PRINT_MAT(a);
+
+	AT(b, 1, 1) = 1; AT(b, 2, 1) = 0; AT(b, 3, 1) = 0;
+	AT(b, 1, 2) = 0; AT(b, 2, 2) = 1; AT(b, 3, 2) = 0;
+	AT(b, 1, 3) = 0; AT(b, 2, 3) = 0; AT(b, 3, 3) = 1;
+	PRINT_MAT(b);
+
+	mult = mul(a,b);
+	PRINT_MAT(mult);
+	
+}
+
+MAT *new(uint8_t w, uint8_t h){
+	MAT* ret = malloc(sizeof(MAT));
+	ret->w = w; 
+	ret->h = h; 
+	ret->data = malloc(sizeof(int) * w * h);
+	return ret;
+}
+
+MAT *mul(MAT *a, MAT *b){
+	if(a->w != b->h)
+		return NULL;
+	MAT* ret = new(b->w, a->h);
+	for (int i = 1; i <= a->h; ++i) {
+		for (int j = 1; j <= b->w; ++j) {
+			int tmp = 0;
+			for (int k = 1; k <= a->w; ++k) {
+				tmp += AT(a, k, i) * AT(b, j, k);
+			}
+			AT(ret, j, i) = tmp;
+		}
+	}
+	return ret;
+}

bac2/os/chap2/ex5.c

@@ -0,0 +1,41 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+struct node{
+	struct node* prev;
+	void* data;
+};
+
+typedef struct node* LIFO; 
+
+LIFO* mklifo ();
+void push(LIFO* lst , void*);
+void* pop(LIFO* lst);
+
+int main(void)
+{
+	char* t = "test";
+	LIFO* lifo = mklifo();
+	push(lifo, t);
+	printf("%s", (char *)pop(lifo));
+	
+}
+
+LIFO *mklifo (){
+	LIFO* ret = malloc(sizeof(struct node));
+	return ret;
+}
+
+void push(LIFO *lst , void *el){
+	LIFO* next = mklifo();
+	(*lst)->data = el;
+	(*next)->prev = *lst;
+	lst = next;
+}
+
+void *pop(LIFO *lst){
+	void* el;
+	(*lst)->data = el;
+	*lst = (*lst)->prev;
+	return el;
+}