1 files changed, 71 insertions, 0 deletions
diff --git a/write-or-die.c b/write-or-die.c
new file mode 100644
index 000000000000..eab8c8d0b9aa
--- /dev/null
+++ b/write-or-die.c
@@ -0,0 +1,71 @@
+#include "cache.h"
+#include "run-command.h"
+
+/*
+ * Some cases use stdio, but want to flush after the write
+ * to get error handling (and to get better interactive
+ * behaviour - not buffering excessively).
+ *
+ * Of course, if the flush happened within the write itself,
+ * we've already lost the error code, and cannot report it any
+ * more. So we just ignore that case instead (and hope we get
+ * the right error code on the flush).
+ *
+ * If the file handle is stdout, and stdout is a file, then skip the
+ * flush entirely since it's not needed.
+ */
+void maybe_flush_or_die(FILE *f, const char *desc)
+{
+	static int skip_stdout_flush = -1;
+	struct stat st;
+	char *cp;
+
+	if (f == stdout) {
+		if (skip_stdout_flush < 0) {
+			cp = getenv("GIT_FLUSH");
+			if (cp)
+				skip_stdout_flush = (atoi(cp) == 0);
+			else if ((fstat(fileno(stdout), &st) == 0) &&
+				 S_ISREG(st.st_mode))
+				skip_stdout_flush = 1;
+			else
+				skip_stdout_flush = 0;
+		}
+		if (skip_stdout_flush && !ferror(f))
+			return;
+	}
+	if (fflush(f)) {
+		check_pipe(errno);
+		die_errno("write failure on '%s'", desc);
+	}
+}
+
+void fprintf_or_die(FILE *f, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = vfprintf(f, fmt, ap);
+	va_end(ap);
+
+	if (ret < 0) {
+		check_pipe(errno);
+		die_errno("write error");
+	}
+}
+
+void fsync_or_die(int fd, const char *msg)
+{
+	if (fsync(fd) < 0) {
+		die_errno("fsync error on '%s'", msg);
+	}
+}
+
+void write_or_die(int fd, const void *buf, size_t count)
+{
+	if (write_in_full(fd, buf, count) < 0) {
+		check_pipe(errno);
+		die_errno("write error");
+	}
+}