1 files changed, 170 insertions, 0 deletions
diff --git a/buff.c b/buff.c
new file mode 100644
index 0000000..91593bb
--- /dev/null
+++ b/buff.c
@@ -0,0 +1,170 @@
+#include "buff.h"
+
+line_t* __search_pos(int addr){
+  
+  int i;
+  line_t *cur = b_start;
+  for(i=1; i<addr; i++){
+    cur = cur -> next;
+  }
+  return cur;
+}
+
+int read_lines(FILE *fin){
+  
+  char buff[4096];
+  line_t *line;
+  size_t s;
+
+  while(feof(fin) == 0){
+    if (!fgets(buff, 4095, fin)) break;
+    s = strlen(buff) + 1;
+    line = malloc(sizeof(line_t));
+    line->s = s;
+    line->c = malloc(s * sizeof(char));
+    memcpy(line->c, buff, s);
+    line->next = NULL;
+    
+    if (b_start == NULL){
+      line->prev = NULL;
+      b_start = line;
+    }
+    else{
+      b_end->next = line;
+      line->prev = b_end;
+    }
+    b_end = line;
+    num += 1;
+  }
+  cur = b_end;
+  pos = num;
+}
+
+void print_cur_line(char lineno){
+  
+  if (!b_start){
+    printf("?\n");
+    return;
+  }
+  
+  if (lineno)
+    printf("%d\t", pos);
+  printf("%s", cur->c);
+}
+  
+void print_lines(char lineno){
+
+  line_t *p;
+  int i=0;
+  p = b_start;
+
+  
+  printf(">>> *** addr1: %d addr2: %d ***\n", addr1, addr2);
+  for (i=1; i<addr2; i++) p = p->next;
+  pos = i;
+  cur = p;
+  while(pos < addr1){
+    if (lineno)
+      printf("%d\t", pos);
+    printf("%s", cur->c);
+    cur = cur->next;
+    pos += 1;
+  }
+  if (lineno)
+    printf("%d\t", pos);
+  printf("%s", cur->c);
+  if (pos != num) {
+    pos += 1;
+    cur = cur -> next;
+  }
+}
+
+int move_to_line(int addr, char print){
+
+  if (addr > num)
+    return -1;
+  else if (addr >= 0){
+    pos = addr;
+    cur = __search_pos(pos);
+    if (print)
+      print_cur_line(0);
+  }
+  return pos;
+}
+
+void print_lineno(){
+  printf("%d\n", addr1);
+}
+
+int move_forward(int n){
+
+  if (pos + n > num){
+    printf("?\n");
+    return -1;
+  }
+  while(n-- >0){
+    cur = cur->next;
+  }
+  pos += n;
+  return 0;
+}
+
+int move_backward(int n){
+
+  if (pos - n < 1){
+    printf("?\n");
+    return -1;
+  }
+  while(n-- >0){
+    cur = cur->prev;
+  }
+  pos -= n;
+  return 0;
+}
+
+
+
+/* add lines after pos */
+void append_lines(){
+
+  char buff[4096];
+  int n,s;
+  line_t *first, *l, *last;
+  
+  n = 0;
+  first = last = NULL;
+  while(feof(stdin) == 0){
+    if (!fgets(buff, 4095, stdin)) break;
+    if (buff[0] == '.')
+      break;
+    s = strlen(buff) + 1;
+    l = malloc(sizeof(line_t));
+    l->c = malloc(s * sizeof(char));
+    memcpy(l->c, buff, s);
+    l->s = s;
+    if (first == NULL)
+      first = last = l;
+    else{
+      last -> next = l;
+      l->prev = last;
+      last = l;
+    }
+    n += 1;
+  }
+  if (addr1 == 0){
+    last->next = b_start;
+    b_start -> prev = last;
+    b_start = first;
+    move_to_line(n,0);
+  }
+  else{
+    last -> next = cur -> next;
+    cur->next = first;
+    first->prev = cur;
+    move_forward(n);
+  }
+}
+
+void insert_lines(){}
+
+void delete_lines(){}