.

bac2/os/chap1/build.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -xe
+
 for i in $(ls *.c); do
 	gcc $i -o $(echo $i | cut -d '.' -f 1)
 done

bac2/os/chap1/ex1.c

@@ -19,9 +19,16 @@ void handler(int sig, siginfo_t* info, void* context) {
 }
 
 int main(int argc, char *argv[]){
+
 	SIGS context = {.sa_flags = SA_SIGINFO, .sa_sigaction = handler};
-	while(1)
-		pause();
+	sigaction(SIGUSR1, &context, NULL);
+	sigaction(SIGUSR2, &context, NULL);
+
+	while(1){
+		printf("The program is running...\n");
+		sleep(1);
+	}
+
 	return 0;
 }
 

bac2/os/chap1/ex2.c

@@ -0,0 +1,33 @@
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+
+typedef struct sigaction SIGS;
+
+uint8_t kill_counter = 0;
+const char* sentences[] = {
+	"Just give me a moment.",
+	"I said I need a moment!",
+	"Fine. I'm out of here....",
+};
+
+void handler(int sig, siginfo_t* info, void* context) {
+	printf("%s\n", sentences[kill_counter++]);
+	if(kill_counter >= 3)
+		abort();
+}
+
+int main(int argc, char *argv[])
+{
+	SIGS event = {
+		.sa_sigaction = handler,
+		.sa_flags = SA_SIGINFO
+	};
+	sigaction(SIGINT, &event, NULL);
+	while(1)
+		pause();
+
+	return 0;
+}

bac2/os/chap1/ex3.c

@@ -0,0 +1,38 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+
+int counter=1;
+
+void handler(int sig){
+	if(sig == SIGINT){
+		printf("Early ending. the current ammount of application is : %d\n", counter);
+		exit(0);
+	}
+}
+
+int collatz(int n){
+	sleep(1);
+	if (n % 2 == 0)
+		return n / 2;
+	return 3 * n  + 1;
+}
+
+int main(int argc, char *argv[])
+{	
+	signal(SIGINT, handler);
+	if (argc != 2)
+		exit(1);
+	int test = atoi(argv[1]);
+	printf("%d\n", test);
+	while(test != 1){
+		counter++;
+		test = collatz(test);
+		printf("%d\n", test);
+	}
+	printf("---\n%d\n", counter);
+	return 0;
+}
+

bac2/os/chap1/ex4.c

@@ -0,0 +1,26 @@
+#include <signal.h>
+#include <stdio.h>
+
+typedef struct sigaction SIGS;
+
+void handler(int sig, siginfo_t* info, void* context){
+	if(sig == SIGFPE){
+		printf("Division par zero... rip in peperoni...\n");
+		exit(1);
+	}
+
+}
+
+int main(int argc, char *argv[])
+{
+	SIGS event = {
+		.sa_flags = SA_SIGINFO,
+		.sa_sigaction = handler	
+	};
+
+	sigaction(SIGFPE, &event, NULL);
+
+	printf("I want to break free... \n");
+	printf("%d\n", 1/0);
+	return 0;
+}

bac2/os/chap1/ex5.c

@@ -0,0 +1,19 @@
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+
+void handler(int sig){
+	if(sig == SIGINT)
+		while(1)
+			printf("I cannot DIE !!!!\n");
+}
+
+int main(int argc, char *argv[])
+{
+	signal(SIGINT, handler);
+	signal(SIGQUIT, handler);
+	signal(SIGTERM, handler);
+	while(1)
+		pause();
+	return 0;
+}

bac2/os/chap1/ex6.c

@@ -0,0 +1,22 @@
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+void handler(int sig){
+	printf("test");
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	signal(SIGALRM, handler);
+
+
+	alarm(5);
+	
+	getchar();
+	printf("finished without a thing");
+
+	return 0;
+}

bac2/os/chap1/group.c

@@ -0,0 +1,50 @@
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <termios.h>
+#include <assert.h>
+#include <string.h>
+
+struct {
+	int index;
+	char tab[1024];
+} buf = {0};
+
+struct termios term, previous; // the previous state has to be restored... if not the term stay in that mode
+
+void handler(int sig){
+	switch (sig) {
+		case SIGALRM:
+			for (int i = 0; i < buf.index; ++i) {
+				if(!buf.tab[i])
+					continue;
+				printf("%c", buf.tab[i] + 'A' - 'a');
+			}
+			alarm(5);
+			break;
+		default:
+			tcsetattr(STDIN_FILENO, TCSANOW, &previous);
+			raise(sig);
+			assert(1);
+			break;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	signal(SIGALRM, handler);
+	signal(SIGINT, handler);
+
+	tcgetattr(STDIN_FILENO, &previous);
+    memcpy(&term, &previous, sizeof(struct termios));
+	term.c_lflag &= ~ICANON;
+	tcsetattr(STDIN_FILENO, TCSANOW, &term);
+
+	alarm(5);
+	
+	while(1){
+		buf.tab[buf.index++] = getchar();
+	}
+	assert(1);
+}

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;
+}