1 files changed, 114 insertions, 0 deletions
diff --git a/include/closestream.h b/include/closestream.h
new file mode 100644
index 0000000..711ca5b
--- /dev/null
+++ b/include/closestream.h
@@ -0,0 +1,114 @@
+/*
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
+ */
+#ifndef UTIL_LINUX_CLOSESTREAM_H
+#define UTIL_LINUX_CLOSESTREAM_H
+
+#include <stdio.h>
+#ifdef HAVE_STDIO_EXT_H
+#include <stdio_ext.h>
+#endif
+#include <unistd.h>
+
+#include "c.h"
+#include "nls.h"
+
+#ifndef CLOSE_EXIT_CODE
+# define CLOSE_EXIT_CODE EXIT_FAILURE
+#endif
+
+static inline int
+close_stream(FILE * stream)
+{
+#ifdef HAVE___FPENDING
+	const int some_pending = (__fpending(stream) != 0);
+#endif
+	const int prev_fail = (ferror(stream) != 0);
+	const int fclose_fail = (fclose(stream) != 0);
+
+	if (prev_fail || (fclose_fail && (
+#ifdef HAVE___FPENDING
+					  some_pending ||
+#endif
+					  errno != EBADF))) {
+		if (!fclose_fail && !(errno == EPIPE))
+			errno = 0;
+		return EOF;
+	}
+	return 0;
+}
+
+static inline int
+flush_standard_stream(FILE *stream)
+{
+	int fd;
+
+	errno = 0;
+
+	if (ferror(stream) != 0 || fflush(stream) != 0)
+		goto error;
+
+	/*
+	 * Calling fflush is not sufficient on some filesystems
+	 * like e.g. NFS, which may defer the actual flush until
+	 * close. Calling fsync would help solve this, but would
+	 * probably result in a performance hit. Thus, we work
+	 * around this issue by calling close on a dup'd file
+	 * descriptor from the stream.
+	 */
+	if ((fd = fileno(stream)) < 0 || (fd = dup(fd)) < 0 || close(fd) != 0)
+		goto error;
+
+	return 0;
+error:
+	return (errno == EBADF) ? 0 : EOF;
+}
+
+/* Meant to be used atexit(close_stdout); */
+static inline void
+close_stdout(void)
+{
+	if (flush_standard_stream(stdout) != 0 && !(errno == EPIPE)) {
+		if (errno)
+			warn(_("write error"));
+		else
+			warnx(_("write error"));
+		_exit(CLOSE_EXIT_CODE);
+	}
+
+	if (flush_standard_stream(stderr) != 0)
+		_exit(CLOSE_EXIT_CODE);
+}
+
+static inline void
+close_stdout_atexit(void)
+{
+	/*
+	 * Note that close stdout at exit disables ASAN to report memory leaks
+	 */
+#if !HAS_FEATURE_ADDRESS_SANITIZER
+	atexit(close_stdout);
+#endif
+}
+
+#ifndef HAVE_FSYNC
+static inline int
+fsync(int fd __attribute__((__unused__)))
+{
+	return 0;
+}
+#endif
+
+static inline int
+close_fd(int fd)
+{
+	const int fsync_fail = (fsync(fd) != 0);
+	const int close_fail = (close(fd) != 0);
+
+	if (fsync_fail || close_fail)
+		return EOF;
+	return 0;
+}
+
+#endif /* UTIL_LINUX_CLOSESTREAM_H */