Added shred

src/shred.c

@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <errno.h>
+
+int
+count_bytes(const char *filename)
+{
+  int fd = open(filename,O_RDWR);
+  if(fd == -1)
+    {
+      printf("Error reading file: %i = %s\n",errno,strerror(errno));
+      return 1;
+    }
+  int bytes_read = 0;
+  char *buf = NULL;
+  int bytes = 0;
+  buf = malloc(1);
+  while ((bytes_read = read(fd,buf,1)) > 0)
+    bytes++;
+  return bytes;
+}
+
+int
+fill_with_zeroes(const char *filename)
+{
+  int fd = open(filename,O_RDWR);
+  if(fd == -1)
+    {
+      printf("Error reading file: %i = %s\n",errno,strerror(errno));
+      return 1;
+    }
+  int bytes_to_write = count_bytes(filename);
+  int bytes_read = 0;
+  char *buf = NULL;
+  int bytes = 0;
+  buf = malloc(bytes_to_write);
+  while((bytes_read = read(fd,buf,bytes_to_write)) > 0)
+    write(fd,"\0",bytes_to_write + 4096);
+  free(buf);
+  return 0;
+}
+
+int
+main(int argc, char *argv[])
+{
+  int c = getopt(argc, argv, "u"); /* TODO: add -f */
+  
+  fill_with_zeroes(argv[1]);
+  if(c == 'u')
+    remove(argv[1]);
+}