Advance implementation of edit command.

programs/edit.c

@@ -1,11 +1,16 @@
 #include <sys/unistd.h>
+#include <sys/stat.h>
+#include <strerror.h>
 #include <termios.h>
 #include <stdbool.h>
+#include <string.h>
 #include <debug.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <fcntl.h>
 
 #define CTRL_KEY(k) ((k)&0x1f)
+#define BUFFER_SIZE 4096
 
 static struct termios _original_termios, _termios;
 
@@ -30,19 +35,70 @@ static inline void enable_raw_mode()
 
 int main(int argc, char *argv[])
 {
+    if (argc != 2) {
+        printf("edit: missing operand.\n");
+        printf("Try 'edit --help' for more information.\n\n");
+        return 1;
+    }
+    if (strcmp(argv[1], "--help") == 0) {
+        printf("Prints the content of the given file.\n");
+        printf("Usage:\n");
+        printf("    edit <file>\n\n");
+        return 0;
+    }
+    int fd = open(argv[1], O_RDONLY, 42);
+    if (fd < 0) {
+        printf("edit: %s: %s\n\n", argv[0], strerror(errno));
+        return 1;
+    }
+    stat_t statbuf;
+    if (fstat(fd, &statbuf) == -1) {
+        printf("edit: %s: %s\n\n", argv[0], strerror(errno));
+        // Close the file descriptor.
+        close(fd);
+        return 1;
+    }
+    if (S_ISDIR(statbuf.st_mode)) {
+        printf("edit: %s: %s\n\n", argv[0], strerror(EISDIR));
+        // Close the file descriptor.
+        close(fd);
+        return 1;
+    }
+    // Put on the standard output the characters.
+    char buffer[BUFFER_SIZE];
+    while (read(fd, buffer, BUFFER_SIZE) > 0) {
+        puts(buffer);
+    }
+    // Close the file descriptor.
+    close(fd);
+
     enable_raw_mode();
 
     int c;
     do {
         c = getchar();
-        if (iscntrl(c)) {
-            printf("%d\n", c);
+        // Return Key
+        if (c == '\n') {
+            putchar('\n');
+        } else if (c == '\033') {
+            c = getchar();
+            if (c == '[') {
+                c = getchar();
+                if (c == 'D') {
+                    puts("\033[1D");
+                } else if (c == 'C') {
+                    puts("\033[1C");
+                } else if (c == 'H') {
+                    printf("\033[%dD", 0);
+                } else if (c == 'F') {
+                    printf("\033[%dC", 60);
+                }
+            }
         } else {
-            printf("%d ('%c')\n", c, c);
+            putchar(c);
         }
     } while (c != 'q');
 
     disable_raw_mode();
-
     return 0;
 }