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