Document git-patch-id a bit better.
[git.git] / 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