Implement writing to disk

include/buffer.h

@@ -1,6 +1,8 @@
 #ifndef BUFFER_H
 #define BUFFER_H
 
+#include "utils.h"
+
 struct erow {
     char *chars;
     int n_chars;
@@ -18,6 +20,7 @@ struct buffer {
 struct buffer *buffer_create(void);
 void buffer_read_file(struct buffer *buffer, const char *filename);
 void buffer_append_row(struct buffer *buffer, const char *chars, int n_chars);
+ERRCODE buffer_write_file(struct buffer *buffer);
 
 void erow_update_rendering(struct erow *erow);
 void erow_insert_char(struct erow *erow, int at, char c);

include/commands.h

@@ -5,5 +5,6 @@
 
 void command_move_cursor(KEY key);
 void command_insert_char(char c);
+void command_save_buffer(void);
 
 #endif // COMMANDS_H

include/input.h

@@ -5,6 +5,7 @@
 
 enum KEYS {
     TAB = 9,
+    BACKSPACE = 127,
     HOME = 0x100,
     DEL,
     PG_UP,

src/buffer.c

@@ -1,7 +1,9 @@
+#include <fcntl.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #include "buffer.h"
 #include "kilo.h"
@@ -19,6 +21,7 @@ struct buffer *buffer_create(void) {
     return buf;
 }
 
+// TODO: Handle file not existing
 void buffer_read_file(struct buffer *buffer, const char *filename) {
     if (buffer->filename)
         free(buffer->filename);
@@ -56,6 +59,33 @@ void buffer_read_file(struct buffer *buffer, const char *filename) {
     fclose(file);
 }
 
+ERRCODE buffer_write_file(struct buffer *buffer) {
+    if (buffer->filename == NULL)
+        return -1;
+
+    size_t len = 0;
+
+    for (int i = 0; i < buffer->n_rows; i++)
+        len += buffer->rows[i].n_chars + 1;
+
+    char *write_buffer = malloc(len);
+    char *p = write_buffer;
+    for (int i = 0; i < buffer->n_rows; i++) {
+        struct erow *row = buffer->rows+i;
+        memcpy(p, row->chars, row->n_chars);
+        p += row->n_chars;
+        *p = '\n';
+        p++;
+    }
+
+    int fd = open(buffer->filename, O_RDWR | O_TRUNC | O_CREAT, 0644);
+    write(fd, write_buffer, len);
+    close(fd);
+    free(write_buffer);
+
+    return 0;
+}
+
 void buffer_append_row(struct buffer *buffer, const char *chars, int n_chars) {
     buffer->rows = realloc(buffer->rows, sizeof(struct erow) * (buffer->n_rows + 1));
     struct erow *new_row = &buffer->rows[buffer->n_rows++];

src/commands.c

@@ -4,6 +4,7 @@
 #include "input.h"
 #include "kilo.h"
 #include "buffer.h"
+#include "utils.h"
 
 static void cursor_adjust_viewport(void);
 static void cursor_check_file_bounds(bool horizontal);
@@ -63,6 +64,15 @@ void command_insert_char(char c) {
     E.rx = erow_cx_to_rx(E.current_buf->rows+E.cy, E.cx);
 }
 
+void command_save_buffer(void) {
+    ERRCODE errcode = buffer_write_file(E.current_buf);
+
+    if (errcode == 0)
+        editor_set_message("Saved file %s", E.current_buf->filename);
+    else if (errcode == -1)
+        editor_set_message("Save failed, no filename");
+}
+
 static void cursor_check_file_bounds(bool horizontal) {
     struct erow *rows = E.current_buf->rows;
     int n_rows = E.current_buf->n_rows;

src/input.c

@@ -20,6 +20,10 @@ void input_process_key(void) {
             command_move_cursor(c);
             break;
 
+        case CTRL_KEY('S'):
+            command_save_buffer();
+            break;
+
         case CTRL_KEY('Q'):
             terminal_clear();
             exit(0);
@@ -28,9 +32,13 @@ void input_process_key(void) {
         case '\r':
             break;
 
-        case 127:
-        case DEL:
+        case BACKSPACE:
         case CTRL_KEY('H'):
+        case DEL:
+            break;
+
+        case CTRL_KEY('L'):
+        // case NOP:
             break;
 
         default:

src/kilo.c

@@ -45,7 +45,7 @@ void editor_init(char *filename) {
     if (filename)
         buffer_read_file(E.current_buf, filename);
 
-    editor_set_message("Welcome to kilo. Press CTRL-Q to quit.");
+    editor_set_message("Welcome to kilo! | CTRL-Q: Quit | CTRL-S: SAVE");
     terminal_clear();
 }