write_or_die.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3
   4 static void check_pipe(int err)
   5 {
   6         if (err == EPIPE) {
   7                 if (in_async())
   8                         async_exit(141);
   9
  10                 signal(SIGPIPE, SIG_DFL);
  11                 raise(SIGPIPE);
  12                 /* Should never happen, but just in case... */
  13                 exit(141);
  14         }
  15 }
  16
  17 /*
  18  * Some cases use stdio, but want to flush after the write
  19  * to get error handling (and to get better interactive
  20  * behaviour - not buffering excessively).
  21  *
  22  * Of course, if the flush happened within the write itself,
  23  * we've already lost the error code, and cannot report it any
  24  * more. So we just ignore that case instead (and hope we get
  25  * the right error code on the flush).
  26  *
  27  * If the file handle is stdout, and stdout is a file, then skip the
  28  * flush entirely since it's not needed.
  29  */
  30 void maybe_flush_or_die(FILE *f, const char *desc)
  31 {
  32         static int skip_stdout_flush = -1;
  33         struct stat st;
  34         char *cp;
  35
  36         if (f == stdout) {
  37                 if (skip_stdout_flush < 0) {
  38                         cp = getenv("GIT_FLUSH");
  39                         if (cp)
  40                                 skip_stdout_flush = (atoi(cp) == 0);
  41                         else if ((fstat(fileno(stdout), &st) == 0) &&
  42                                  S_ISREG(st.st_mode))
  43                                 skip_stdout_flush = 1;
  44                         else
  45                                 skip_stdout_flush = 0;
  46                 }
  47                 if (skip_stdout_flush && !ferror(f))
  48                         return;
  49         }
  50         if (fflush(f)) {
  51                 check_pipe(errno);
  52                 die_errno("write failure on '%s'", desc);
  53         }
  54 }
  55
  56 void fprintf_or_die(FILE *f, const char *fmt, ...)
  57 {
  58         va_list ap;
  59         int ret;
  60
  61         va_start(ap, fmt);
  62         ret = vfprintf(f, fmt, ap);
  63         va_end(ap);
  64
  65         if (ret < 0) {
  66                 check_pipe(errno);
  67                 die_errno("write error");
  68         }
  69 }
  70
  71 void fsync_or_die(int fd, const char *msg)
  72 {
  73         if (fsync(fd) < 0) {
  74                 die_errno("fsync error on '%s'", msg);
  75         }
  76 }
  77
  78 void write_or_die(int fd, const void *buf, size_t count)
  79 {
  80         if (write_in_full(fd, buf, count) < 0) {
  81                 check_pipe(errno);
  82                 die_errno("write error");
  83         }
  84 }
  85
  86 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
  87 {
  88         if (write_in_full(fd, buf, count) < 0) {
  89                 check_pipe(errno);
  90                 fprintf(stderr, "%s: write error (%s)\n",
  91                         msg, strerror(errno));
  92                 return 0;
  93         }
  94
  95         return 1;
  96 }