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 = read(ifd, buffer, sizeof(buffer));
  10                 if (!len)
  11                         break;
  12                 if (len < 0) {
  13                         if (errno == EAGAIN)
  14                                 continue;
  15                         return error("copy-fd: read returned %s",
  16                                      strerror(errno));
  17                 }
  18                 while (1) {
  19                         int written = write(ofd, buf, len);
  20                         if (written > 0) {
  21                                 buf += written;
  22                                 len -= written;
  23                                 if (!len)
  24                                         break;
  25                         }
  26                         if (!written)
  27                                 return error("copy-fd: write returned 0");
  28                         if (errno == EAGAIN || errno == EINTR)
  29                                 continue;
  30                         return error("copy-fd: write returned %s",
  31                                      strerror(errno));
  32                 }
  33         }
  34         close(ifd);
  35         return 0;
  36 }
  37