write_or_die.c

   1 #include "cache.h"
   2
   3 int read_in_full(int fd, void *buf, size_t count)
   4 {
   5         char *p = buf;
   6         ssize_t total = 0;
   7         ssize_t loaded = 0;
   8
   9         while (count > 0) {
  10                 loaded = xread(fd, p, count);
  11                 if (loaded <= 0) {
  12                         if (total)
  13                                 return total;
  14                         else
  15                                 return loaded;
  16                 }
  17                 count -= loaded;
  18                 p += loaded;
  19                 total += loaded;
  20         }
  21
  22         return total;
  23 }
  24
  25 void read_or_die(int fd, void *buf, size_t count)
  26 {
  27         ssize_t loaded;
  28
  29         if (!count)
  30                 return;
  31         loaded = read_in_full(fd, buf, count);
  32         if (loaded == 0)
  33                 die("unexpected end of file");
  34         else if (loaded < 0)
  35                 die("read error (%s)", strerror(errno));
  36 }
  37
  38 int write_in_full(int fd, const void *buf, size_t count)
  39 {
  40         const char *p = buf;
  41         ssize_t total = 0;
  42
  43         while (count > 0) {
  44                 size_t written = xwrite(fd, p, count);
  45                 if (written < 0)
  46                         return -1;
  47                 if (!written) {
  48                         errno = ENOSPC;
  49                         return -1;
  50                 }
  51                 count -= written;
  52                 p += written;
  53                 total += written;
  54         }
  55
  56         return total;
  57 }
  58
  59 void write_or_die(int fd, const void *buf, size_t count)
  60 {
  61         if (write_in_full(fd, buf, count) < 0) {
  62                 if (errno == EPIPE)
  63                         exit(0);
  64                 die("write error (%s)", strerror(errno));
  65         }
  66 }
  67
  68 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  69 {
  70         if (write_in_full(fd, buf, count) < 0) {
  71                 if (errno == EPIPE)
  72                         exit(0);
  73                 fprintf(stderr, "%s: write error (%s)\n",
  74                         msg, strerror(errno));
  75                 return 0;
  76         }
  77
  78         return 1;
  79 }
  80
  81 int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
  82 {
  83         if (write_in_full(fd, buf, count) < 0) {
  84                 fprintf(stderr, "%s: write error (%s)\n",
  85                         msg, strerror(errno));
  86                 return 0;
  87         }
  88
  89         return 1;
  90 }