include/all-io.h

   1 /*
   2  * No copyright is claimed.  This code is in the public domain; do with
   3  * it what you wish.
   4  *
   5  * Written by Karel Zak <kzak@redhat.com>
   6  *            Petr Uzel <petr.uzel@suse.cz>
   7  */
   8
   9 #ifndef UTIL_LINUX_ALL_IO_H
  10 #define UTIL_LINUX_ALL_IO_H
  11
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <errno.h>
  15
  16 #include "c.h"
  17
  18 static inline int write_all(int fd, const void *buf, size_t count)
  19 {
  20         while (count) {
  21                 ssize_t tmp;
  22
  23                 errno = 0;
  24                 tmp = write(fd, buf, count);
  25                 if (tmp > 0) {
  26                         count -= tmp;
  27                         if (count)
  28                                 buf = (const void *) ((const char *) buf + tmp);
  29                 } else if (errno != EINTR && errno != EAGAIN)
  30                         return -1;
  31                 if (errno == EAGAIN)    /* Try later, *sigh* */
  32                         xusleep(250000);
  33         }
  34         return 0;
  35 }
  36
  37 static inline int fwrite_all(const void *ptr, size_t size,
  38                              size_t nmemb, FILE *stream)
  39 {
  40         while (nmemb) {
  41                 size_t tmp;
  42
  43                 errno = 0;
  44                 tmp = fwrite(ptr, size, nmemb, stream);
  45                 if (tmp > 0) {
  46                         nmemb -= tmp;
  47                         if (nmemb)
  48                                 ptr = (const void *) ((const char *) ptr + (tmp * size));
  49                 } else if (errno != EINTR && errno != EAGAIN)
  50                         return -1;
  51                 if (errno == EAGAIN)    /* Try later, *sigh* */
  52                         xusleep(250000);
  53         }
  54         return 0;
  55 }
  56
  57 static inline ssize_t read_all(int fd, char *buf, size_t count)
  58 {
  59         ssize_t ret;
  60         ssize_t c = 0;
  61         int tries = 0;
  62
  63         memset(buf, 0, count);
  64         while (count > 0) {
  65                 ret = read(fd, buf, count);
  66                 if (ret <= 0) {
  67                         if (ret < 0 && (errno == EAGAIN || errno == EINTR) && (tries++ < 5)) {
  68                                 xusleep(250000);
  69                                 continue;
  70                         }
  71                         return c ? c : -1;
  72                 }
  73                 tries = 0;
  74                 count -= ret;
  75                 buf += ret;
  76                 c += ret;
  77         }
  78         return c;
  79 }
  80
  81 #endif /* UTIL_LINUX_ALL_IO_H */