copy.c

   1 #include "cache.h"
   2
   3 int copy_fd(int ifd, int ofd)
   4 {
   5         while (1) {
   6                 int len;
   7                 char buffer[8192];
   8                 char *buf = buffer;
   9                 len = xread(ifd, buffer, sizeof(buffer));
  10                 if (!len)
  11                         break;
  12                 if (len < 0) {
  13                         int read_error;
  14                         read_error = errno;
  15                         close(ifd);
  16                         return error("copy-fd: read returned %s",
  17                                      strerror(read_error));
  18                 }
  19                 while (len) {
  20                         int written = xwrite(ofd, buf, len);
  21                         if (written > 0) {
  22                                 buf += written;
  23                                 len -= written;
  24                         }
  25                         else if (!written) {
  26                                 close(ifd);
  27                                 return error("copy-fd: write returned 0");
  28                         } else {
  29                                 close(ifd);
  30                                 return error("copy-fd: write returned %s",
  31                                              strerror(errno));
  32                         }
  33                 }
  34         }
  35         close(ifd);
  36         return 0;
  37 }
  38