write_or_die.c

   1 #include "cache.h"
   2
   3 /*
   4  * Some cases use stdio, but want to flush after the write
   5  * to get error handling (and to get better interactive
   6  * behaviour - not buffering excessively).
   7  *
   8  * Of course, if the flush happened within the write itself,
   9  * we've already lost the error code, and cannot report it any
  10  * more. So we just ignore that case instead (and hope we get
  11  * the right error code on the flush).
  12  *
  13  * If the file handle is stdout, and stdout is a file, then skip the
  14  * flush entirely since it's not needed.
  15  */
  16 void maybe_flush_or_die(FILE *f, const char *desc)
  17 {
  18         static int skip_stdout_flush = -1;
  19         struct stat st;
  20         char *cp;
  21
  22         if (f == stdout) {
  23                 if (skip_stdout_flush < 0) {
  24                         cp = getenv("GIT_FLUSH");
  25                         if (cp)
  26                                 skip_stdout_flush = (atoi(cp) == 0);
  27                         else if ((fstat(fileno(stdout), &st) == 0) &&
  28                                  S_ISREG(st.st_mode))
  29                                 skip_stdout_flush = 1;
  30                         else
  31                                 skip_stdout_flush = 0;
  32                 }
  33                 if (skip_stdout_flush && !ferror(f))
  34                         return;
  35         }
  36         if (fflush(f)) {
  37                 /*
  38                  * On Windows, EPIPE is returned only by the first write()
  39                  * after the reading end has closed its handle; subsequent
  40                  * write()s return EINVAL.
  41                  */
  42                 if (errno == EPIPE || errno == EINVAL)
  43                         exit(0);
  44                 die("write failure on %s: %s", desc, strerror(errno));
  45         }
  46 }
  47
  48 void fsync_or_die(int fd, const char *msg)
  49 {
  50         if (fsync(fd) < 0) {
  51                 die("%s: fsync error (%s)", msg, strerror(errno));
  52         }
  53 }
  54
  55 void write_or_die(int fd, const void *buf, size_t count)
  56 {
  57         if (write_in_full(fd, buf, count) < 0) {
  58                 if (errno == EPIPE)
  59                         exit(0);
  60                 die("write error (%s)", strerror(errno));
  61         }
  62 }
  63
  64 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  65 {
  66         if (write_in_full(fd, buf, count) < 0) {
  67                 if (errno == EPIPE)
  68                         exit(0);
  69                 fprintf(stderr, "%s: write error (%s)\n",
  70                         msg, strerror(errno));
  71                 return 0;
  72         }
  73
  74         return 1;
  75 }
  76
  77 int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
  78 {
  79         if (write_in_full(fd, buf, count) < 0) {
  80                 fprintf(stderr, "%s: write error (%s)\n",
  81                         msg, strerror(errno));
  82                 return 0;
  83         }
  84
  85         return 1;
  86 }