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         loaded = read_in_full(fd, buf, count);
  30         if (loaded == 0)
  31                 die("unexpected end of file");
  32         else if (loaded < 0)
  33                 die("read error (%s)", strerror(errno));
  34 }
  35
  36 int write_in_full(int fd, const void *buf, size_t count)
  37 {
  38         const char *p = buf;
  39         ssize_t total = 0;
  40         ssize_t written = 0;
  41
  42         while (count > 0) {
  43                 written = xwrite(fd, p, count);
  44                 if (written <= 0) {
  45                         if (total)
  46                                 return total;
  47                         else
  48                                 return written;
  49                 }
  50                 count -= written;
  51                 p += written;
  52                 total += written;
  53         }
  54
  55         return total;
  56 }
  57
  58 void write_or_die(int fd, const void *buf, size_t count)
  59 {
  60         ssize_t written;
  61
  62         written = write_in_full(fd, buf, count);
  63         if (written == 0)
  64                 die("disk full?");
  65         else if (written < 0) {
  66                 if (errno == EPIPE)
  67                         exit(0);
  68                 die("write error (%s)", strerror(errno));
  69         }
  70 }
  71
  72 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  73 {
  74         ssize_t written;
  75
  76         written = write_in_full(fd, buf, count);
  77         if (written == 0) {
  78                 fprintf(stderr, "%s: disk full?\n", msg);
  79                 return 0;
  80         }
  81         else if (written < 0) {
  82                 if (errno == EPIPE)
  83                         exit(0);
  84                 fprintf(stderr, "%s: write error (%s)\n",
  85                         msg, strerror(errno));
  86                 return 0;
  87         }
  88
  89         return 1;
  90 }
  91
  92 int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
  93 {
  94         ssize_t written;
  95
  96         written = write_in_full(fd, buf, count);
  97         if (written == 0) {
  98                 fprintf(stderr, "%s: disk full?\n", msg);
  99                 return 0;
 100         }
 101         else if (written < 0) {
 102                 fprintf(stderr, "%s: write error (%s)\n",
 103                         msg, strerror(errno));
 104                 return 0;
 105         }
 106
 107         return 1;
 108 }